E07.08 - Leak Testing Method

ABSTRACT
This practice establishes the standard procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. The two types of leaks considered here are Type I, which is pressure to vacuum, and Type II, which is pressure to atmosphere. Three calibration methods are described under each type of reference leak, as follows: Method A—accumulation comparison using a known volume of tracer gas at specified conditions of temperature and pressure as a reference; Method B—accumulation comparison using a reference leak artifact calibrated using Method A; and Method C—direct measurement of leak rate by timing the movement (displacement) of a liquid slug, by the leak, in a capillary tube of known dimensions.
SCOPE
1.1 This practice covers procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. While the uncertainties associated with these procedures will most likely be greater than those obtained via traceable calibration chains (on the order of 10 %), these procedures allow independent means of establishing or verifying the leakage rate from leak artifacts of questionable history, or when traceable leak artifacts are not available.  
1.2 Two types of leaks are considered:  
1.2.1 Type I—Pressure to vacuum.  
1.2.2 Type II—Pressure to atmosphere.  
1.3 Three calibration methods are described under each type of reference leak:  
1.3.1 Method A—Accumulation comparison, using a known volume of gas at specified conditions of temperature and pressure as a reference.  
1.3.2 Method B—Accumulation comparison, using a leak artifact calibrated using Method A.  
1.3.3 Method C—Displacement of a liquid slug, by the leak, in capillary tube of known dimensions.  
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 This practice is useful for quality control testing and field inspection of piping systems, pipelines, valves, and containers that are expected to retain liquids. It is not sensitive enough for leak testing when toxic or explosive gas is expected to be retained under pressure.
SCOPE
1.1 This practice covers the testing of components for leaks by pressurizing them inside with a liquid.  
1.2 This practice can be used on piping, valves, and containers with welded or fitted sections which can be sealed at their ends and which are designed for internal pressure.  
1.3 Basic procedures are described based on the type of inspection used. These procedures should be limited to finding leakage indications of 4.5 × 10−9 mol/s (1 × 10−4 Std cm3/s)2 or larger.  
1.4 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.  
1.5 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 Methods A or B are useful in testing hermetically-sealed devices with internal volumes. Maximum acceptable leak rates have been established for microelectronic devices to assure performance characteristics will not be affected by in-leakage of air, water vapor or other contaminants over the projected life expected. Care must be taken to control the bombing pressure, bombing time and dwell time after bombing or the results can vary substantially.
SCOPE
1.1 This practice2 covers procedures for testing devices that are sealed prior to testing, such as semiconductors, hermetically enclosed relays, pyrotechnic devices, etc., for leakage through the walls of the enclosure. They may be used with various degrees of sensitivity (depending on the internal volume, the strength of the enclosure, the time available for preparation of test, and on the sorption characteristics of the enclosure material for helium). In general practice the sensitivity limits are from 10−10  to 10−6 Pa m3/s (10−9 standard cm3/s to 10−5 standard cm3/s at 0°C) for helium, although these limits may be exceeded by several decades in either direction in some circumstances.  
1.2 Two test methods are described:  
1.2.1 Test Method A—Test part preparation by bombing.  
1.2.2 Test Method B—Test part preparation by prefilling.  
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ABSTRACT
This guide deals with the selection of the appropriate leak testing method for either leak measurement or location for a particular system being tested (test system), which may consist either of open units or sealed units. The leak testing method may either be dynamic or static, with the dynamic test method requiring shorter time but lesser sensitivity as compared to static techniques. The choice of the appropriate leak testing method shall involve most importantly the optimization of the sensitivity, cost, and reliability of the test. In the case where various testing methods are available for a particular test system, each shall be examined separately and then ranked according to test system sensitivity. However, when determining the sensitivity, it is important to be able to differentiate the sensitivity associated with the instrument used to measure leakage from the sensitivity of the test system followed using the instrument. While the sensitivity of a specific test is dependent on the sensitivity of the instrument used, the choice of instrument and the test system are both influenced by the range of temperatures or pressures and the kinds of fluids involved.
SCOPE
1.1 This guide2 is intended to assist in the selection of a leak testing method.3 Fig. 1 is supplied as a simplified guide.
FIG. 1 Guide for Selection of Leakage Testing Method  
1.2 The type of item to be tested or the test system and the method considered for either leak measurement or location are related in the order of increasing sensitivity.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 Test Method A is the most frequently used in leak testing components which are structurally capable of being evacuated to pressures of 0.1 Pa (approximately 10−3 torr). Testing of small components can be correlated to calibrated leaks, and the actual leak rate can be measured or acceptance can be based on a maximum allowable leak. For most production needs acceptance is based on acceptance of parts leaking less than an established standard which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with reference leak at a representative place on the test volume. Leak rates are determined by calculating the net gain or loss through a leak in the test part that would cause failure during the expected life of the device.  
6.2 Test Method B is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test or for conditioning parts. As the volume tends to be large, a check of the response time as well as system sensitivity should be made. Volume of the system in liters divided by the speed of the vacuum pump in L/s will give the response time to reach 63 % of the total signal. Response times in excess of a few seconds makes leak detection difficult.  
6.3 Test Method C is to be used only when there is no convenient method of connecting the leak detector to the outlet of the high vacuum pump. If a helium leak detector is used and the high vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle as these pumps leave a relatively high percentage of helium in the high vacuum chamber. This will obscure all but large leaks, and the trace gas will quickly saturate the pumps.
SCOPE
1.1 This practice covers procedures for testing and locating the sources of gas leaking at the rate of 1 × 10 −8 Pa m3/s (1 × 10−9  Std cm 3/s)3 or greater. The test may be conducted on any object to be tested that can be evacuated and to the other side of which helium or other tracer gas may be applied.  
1.2 Three test methods are described:  
1.2.1 Test Method A—For the object under test capable of being evacuated, but having no inherent pumping capability.  
1.2.2 Test Method B—For the object under test with integral pumping capability.  
1.2.3 Test Method C—For the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector.  
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 The immersion technique is frequently used to locate leaks in sealed containers. Leaks in a container can be seen independently. Leak size can be approximated by the size of the bubble. It is not suitable for measurement of total system leakage.  
6.2 The liquid film technique is widely applied to components and systems that can not easily be immersed and is used to rapidly locate leaks. An approximation of leak size can be made based on the type of bubbles formed, but the technique is not suitable for measuring leakage rate. It can be used with a vacuum box to test vessels which cannot be pressurized or where only one side is accessible.  
6.3 Accuracy—This practice is not intended to measure leakage rates, but to locate leaks on a go, no-go basis. Their accuracy for locating leaks of 4.5 × 10 −10 mol/s (1 × 10−4 Std cm3/s)2 and larger is ±5 %. Accuracy for locating smaller leaks depends upon the skill of the operator.  
6.4 Repeatability—On a go, no-go basis, duplicate tests by the same operator should not vary by more than ±5 % for leaks of 4.5 × 10 −9 mol/s (1 × 10−4 Std cm3/s).2  
6.5 Reproducibility—On a go, no-go basis, duplicate tests by other trained operators should not vary by more than 10 % for leaks of 4.5 × 10 −9 mol/s (1 × 10−4 Std cm3/s)2 and larger.
SCOPE
1.1 This practice covers procedures for detecting or locating leaks, or both, by bubble emission techniques. A quantitative measure is not practical. The normal limit of sensitivity for this test method is 4.5 × 10−10 mol/s (1 × 10−5 Std cm3/s).2  
1.2 Two techniques are described:  
1.2.1 Immersion technique, and  
1.2.2 Liquid application technique.
Note 1: Additional information is available in ASME Boiler and Pressure Vessel Code, Section V, Article 10-Leak Testing, and Guide E479.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 Practice A—This practice is useful for locating and estimating the size of pressurized gas leaks, either as a quality control test or as a field inspection procedure. It is also valuable as a pretest before other more time consuming and more sensitive leak tests are employed. It should not be used exclusively to locate highly toxic or explosive gas leaks.  
6.2 Practice B—This practice is useful for locating leaks in systems that are not under pressure or vacuum as either a quality control or a field inspection procedure. It is not useful for estimating the size of a leak. It is also valuable as a pretest before leak tests using pressurized gas methods and more sensitive leak tests are employed.
SCOPE
1.1 Practice A, Pressurization—This practice covers procedures for calibration of ultrasonic instruments, location, and estimated measurements of gas leakage to atmosphere by the airborne ultrasonic technique.2  
1.2 In general practice this should be limited to leaks detected by two classifications of instruments, Class I and Class II. Class I instruments should have a minimum detectable leak rate of 6.7 × 10−7 mol/s (1.5 × 10 −2 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Class II instruments should have a minimal detectable leak rate of 6.7 × 10 −6 mol/s (1.5 × 10−1 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Refer to Guide E432 for additional information.  
1.3 Practice B, Ultrasonic Transmitter—For object under test not capable of being pressurized but capable of having ultrasonic tone placed/injected into the test area to act as an ultrasonic leak trace source.  
1.3.1 This practice is limited to leaks producing leakage of 6.7 × 10−6 mol/s (1.5 × 10 −1 std. cm3/s at 0°C) or greater.  
1.4 The values stated in SI units are to be regarded as the standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 Test Method A—This test method is the most frequently used in leak testing components. Testing of components is correlated to a standard leak, and the actual leak rate is measured. Acceptance is based on the maximum system allowable leakage. For most production needs, acceptance is based on acceptance of parts leaking less than an established leakage rate, which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with the standard leak located at a representative place on the test volume. As the volume tends to be large (>1 m3) and there are often low conductance paths involved, a check of the response time as well as system sensitivity should be made.  
5.2 Test Method B—This test method is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test, or conditioning parts. As with Test Method A, the response time and a system sensitivity check may be required for large volumes.  
5.3 Test Method C—This test method is to be used only when there is no convenient method of connecting the LD to the outlet of the high-vacuum pump. If a helium LD is used and the high-vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle, as these pumps leave a relatively high percentage of helium in the high-vacuum chamber. This will limit the maximum sensitivity that can be obtained.
SCOPE
1.1 This practice covers procedures for testing the sources of gas leaking at the rate of 1 × 10 −8 Pa m3/s (1 × 10−9  standard-cm3/s at 0 °C) or greater. These test methods may be conducted on any object that can be evacuated and to the other side of which helium or other tracer gas may be applied. The object must be structurally capable of being evacuated to pressures of 0.1 Pa (approximately 10−3 torr).  
1.2 Three test methods are described;  
1.2.1 Test Method A—For the object under test capable of being evacuated, but having no inherent pumping capability.  
1.2.2 Test Method B—For the object under test with integral pumping capability.  
1.2.3 Test Method C—For the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector (LD).  
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The equipment, test duration, and technique should be determined before commencement of the test based on the required test sensitivity or accuracy (see Annex A1 and Annex A2). If the test is used to certify that the vessel has a minimum specified leakage rate, then the test equipment and test duration should be chosen to have a resolution ten times less than the specification and an accuracy which is four times less than the specification. The test should be designed so that the total pressure change is less than 10 % of the starting pressure. Leak test specifications should specify the vessel test pressure or differential pressure. If the test specification does not specify a test pressure, then a safe test pressure should be used that complies with the applicable safety standards8.
SCOPE
1.1 This practice describes a method for determining the leakage rate of a vessel subject to a positive pressure difference. The technique is based upon evaluation of the change of mass within the test object based on a pressure decay measurement. The pressure decay measurement uses the ideal gas equation of state and the measured pressures, temperatures, and time to determine the mass loss from the vessel. This method does not apply to deformable vessels.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 These test methods are useful for locating and estimating the size of pressurized gas leaks, either as quality control tests or as field inspection procedures. Also, they are valuable as pretests before other more time consuming and more sensitive leak tests are employed. These test methods are semi-quantitative techniques used to locate leaks but cannot be used to quantify except for approximation. These test methods may be used in an accept-reject test mode.
SCOPE
1.1 This practice covers procedures for detecting the sources of gas leaking at the rate of 1 × 10 –5 Pa m3/s (1 × 10–4  standard cm3/s) or greater. The tests may be conducted on any object that can be pressurized with a tracer gas that is detectable by a thermal conductivity detector. The test sensitivity will vary widely depending on the tracer gas used.  
1.2 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 This method is useful for locating and measuring the size of gas leaks either as a quality-control test or as a field-inspection procedure. It can be used to test critical parts or containers that will hold toxic or explosive gases or liquids or as a quick test for other containers.
SCOPE
1.1 This practice covers the testing of large single- and double-walled tanks, pressure and vacuum vessels, laminated, lined- or double-walled parts, complex piping systems, flexible containers (such as aircraft fuel tanks), glass-to-metal seals in hybrid packages, and systems that inherently contain or will contain ammonia (such as large tonnage refrigeration systems and fertilizer storage systems).  
1.2 This method can be used on piping, valves, and containers with welded, fitted, or laminated sections that can be sealed at their ends or between their outer and inner walls and that are designed for internal pressures of 34.5 kPa [5 psig] or greater.  
1.3 Basic procedures are described based on the type of inspection used. These procedures should be limited to finding leakage indications of 4.5 × 10− 12 mol/s [1 × 10−7 Std cm 3/s]2 or larger.  
1.4 Units—The values stated in Std cm3/s or mol/s are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (For more specific safety precautionary information see 7.4, 8.2, 9.4.1, and 10.3.1).  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 Test Method A is frequently used to test large systems and complex piping installations that can be filled with a trace gas. Helium is normally used. The test method is used to locate leaks but cannot be used to quantify except for approximation. Care must be taken to provide sufficient ventilation to prevent increasing the helium background at the test site. Results are limited by the helium background and the percentage of the leaking trace gas captured by the probe.  
6.2 Test Method B is used to increase the concentration of trace gas coming through the leak by capturing it within an enclosure until the signal above the helium background can be detected. By introducing a calibrated leak into the same volume for a recorded time interval, leak rates can be measured.
SCOPE
1.1 This practice covers procedures for testing and locating the sources of gas leaking at the rate of 1 × 10 −7 Pa m3/s (1 × 10−8  Std cm3/s)3 or greater. The test may be conducted on any device or component across which a pressure differential of helium or other suitable tracer gas may be created, and on which the effluent side of the leak to be tested is accessible for probing with the mass spectrometer sampling probe.  
1.2 Two test methods are described:  
1.2.1 Test Method A—Direct probing, and  
1.2.2 Test Method B—Accumulation.  
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 The immersion technique is frequently used to locate leaks in sealed containers. Leaks in a container can be seen independently. Leak size can be approximated by the size of the bubble. It is not suitable for measurement of total system leakage.  
6.2 The liquid film technique is widely applied to components and systems that can not easily be immersed and is used to rapidly locate leaks. An approximation of leak size can be made based on the type of bubbles formed, but the technique is not suitable for measuring leakage rate. It can be used with a vacuum box to test vessels which cannot be pressurized or where only one side is accessible.  
6.3 Accuracy—This practice is not intended to measure leakage rates, but to locate leaks on a go, no-go basis. Their accuracy for locating leaks of 4.5 × 10 −10 mol/s (1 × 10−4 Std cm3/s)2 and larger is ±5 %. Accuracy for locating smaller leaks depends upon the skill of the operator.  
6.4 Repeatability—On a go, no-go basis, duplicate tests by the same operator should not vary by more than ±5 % for leaks of 4.5 × 10 −9 mol/s (1 × 10−4 Std cm3/s).2  
6.5 Reproducibility—On a go, no-go basis, duplicate tests by other trained operators should not vary by more than 10 % for leaks of 4.5 × 10 −9 mol/s (1 × 10−4 Std cm3/s)2 and larger.
SCOPE
1.1 This practice covers procedures for detecting or locating leaks, or both, by bubble emission techniques. A quantitative measure is not practical. The normal limit of sensitivity for this test method is 4.5 × 10−10 mol/s (1 × 10−5 Std cm3/s).2  
1.2 Two techniques are described:  
1.2.1 Immersion technique, and  
1.2.2 Liquid application technique.
Note 1: Additional information is available in ASME Boiler and Pressure Vessel Code, Section V, Article 10-Leak Testing, and Guide E479.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 Practice A—This practice is useful for locating and estimating the size of pressurized gas leaks, either as a quality control test or as a field inspection procedure. It is also valuable as a pretest before other more time consuming and more sensitive leak tests are employed. It should not be used exclusively to locate highly toxic or explosive gas leaks.  
6.2 Practice B—This practice is useful for locating leaks in systems that are not under pressure or vacuum as either a quality control or a field inspection procedure. It is not useful for estimating the size of a leak. It is also valuable as a pretest before leak tests using pressurized gas methods and more sensitive leak tests are employed.
SCOPE
1.1 Practice A, Pressurization—This practice covers procedures for calibration of ultrasonic instruments, location, and estimated measurements of gas leakage to atmosphere by the airborne ultrasonic technique.2  
1.2 In general practice this should be limited to leaks detected by two classifications of instruments, Class I and Class II. Class I instruments should have a minimum detectable leak rate of 6.7 × 10−7 mol/s (1.5 × 10 −2 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Class II instruments should have a minimal detectable leak rate of 6.7 × 10 −6 mol/s (1.5 × 10−1 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Refer to Guide E432 for additional information.  
1.3 Practice B, Ultrasonic Transmitter—For object under test not capable of being pressurized but capable of having ultrasonic tone placed/injected into the test area to act as an ultrasonic leak trace source.  
1.3.1 This practice is limited to leaks producing leakage of 6.7 × 10−6 mol/s (1.5 × 10 −1 std. cm3/s at 0°C) or greater.  
1.4 The values stated in SI units are to be regarded as the standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ABSTRACT
This practice establishes the standard procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. The two types of leaks considered here are Type I, which is pressure to vacuum, and Type II, which is pressure to atmosphere. Three calibration methods are described under each type of reference leak, as follows: Method A—accumulation comparison using a known volume of tracer gas at specified conditions of temperature and pressure as a reference; Method B—accumulation comparison using a reference leak artifact calibrated using Method A; and Method C—direct measurement of leak rate by timing the movement (displacement) of a liquid slug, by the leak, in a capillary tube of known dimensions.
SCOPE
1.1 This practice covers procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. While the uncertainties associated with these procedures will most likely be greater than those obtained via traceable calibration chains (on the order of 10 %), these procedures allow independent means of establishing or verifying the leakage rate from leak artifacts of questionable history, or when traceable leak artifacts are not available.  
1.2 Two types of leaks are considered:  
1.2.1 Type I—Pressure to vacuum.  
1.2.2 Type II—Pressure to atmosphere.  
1.3 Three calibration methods are described under each type of reference leak:  
1.3.1 Method A—Accumulation comparison, using a known volume of gas at specified conditions of temperature and pressure as a reference.  
1.3.2 Method B—Accumulation comparison, using a leak artifact calibrated using Method A.  
1.3.3 Method C—Displacement of a liquid slug, by the leak, in capillary tube of known dimensions.  
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 This practice is useful for quality control testing and field inspection of piping systems, pipelines, valves, and containers that are expected to retain liquids. It is not sensitive enough for leak testing when toxic or explosive gas is expected to be retained under pressure.
SCOPE
1.1 This practice covers the testing of components for leaks by pressurizing them inside with a liquid.  
1.2 This practice can be used on piping, valves, and containers with welded or fitted sections which can be sealed at their ends and which are designed for internal pressure.  
1.3 Basic procedures are described based on the type of inspection used. These procedures should be limited to finding leakage indications of 4.5 × 10−9 mol/s (1 × 10−4 Std cm3/s)2 or larger.  
1.4 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.  
1.5 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ABSTRACT
This guide deals with the selection of the appropriate leak testing method for either leak measurement or location for a particular system being tested (test system), which may consist either of open units or sealed units. The leak testing method may either be dynamic or static, with the dynamic test method requiring shorter time but lesser sensitivity as compared to static techniques. The choice of the appropriate leak testing method shall involve most importantly the optimization of the sensitivity, cost, and reliability of the test. In the case where various testing methods are available for a particular test system, each shall be examined separately and then ranked according to test system sensitivity. However, when determining the sensitivity, it is important to be able to differentiate the sensitivity associated with the instrument used to measure leakage from the sensitivity of the test system followed using the instrument. While the sensitivity of a specific test is dependent on the sensitivity of the instrument used, the choice of instrument and the test system are both influenced by the range of temperatures or pressures and the kinds of fluids involved.
SCOPE
1.1 This guide2 is intended to assist in the selection of a leak testing method.3Fig. 1 is supplied as a simplified guide.
FIG. 1 Guide for Selection of Leakage Testing Method  
1.2 The type of item to be tested or the test system and the method considered for either leak measurement or location are related in the order of increasing sensitivity.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 Methods A or B are useful in testing hermetically-sealed devices with internal volumes. Maximum acceptable leak rates have been established for microelectronic devices to assure performance characteristics will not be affected by in-leakage of air, water vapor or other contaminants over the projected life expected. Care must be taken to control the bombing pressure, bombing time and dwell time after bombing or the results can vary substantially.
SCOPE
1.1 This practice2 covers procedures for testing devices that are sealed prior to testing, such as semiconductors, hermetically enclosed relays, pyrotechnic devices, etc., for leakage through the walls of the enclosure. They may be used with various degrees of sensitivity (depending on the internal volume, the strength of the enclosure, the time available for preparation of test, and on the sorption characteristics of the enclosure material for helium). In general practice the sensitivity limits are from 10−10  to 10−6 Pa m3/s (10−9 standard cm3/s to 10−5 standard cm3/s at 0°C) for helium, although these limits may be exceeded by several decades in either direction in some circumstances.  
1.2 Two test methods are described:  
1.2.1 Test Method A—Test part preparation by bombing.  
1.2.2 Test Method B—Test part preparation by prefilling.  
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
6.1 Test Method A is the most frequently used in leak testing components which are structurally capable of being evacuated to pressures of 0.1 Pa (approximately 10−3 torr). Testing of small components can be correlated to calibrated leaks, and the actual leak rate can be measured or acceptance can be based on a maximum allowable leak. For most production needs acceptance is based on acceptance of parts leaking less than an established standard which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with reference leak at a representative place on the test volume. Leak rates are determined by calculating the net gain or loss through a leak in the test part that would cause failure during the expected life of the device.  
6.2 Test Method B is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test or for conditioning parts. As the volume tends to be large, a check of the response time as well as system sensitivity should be made. Volume of the system in liters divided by the speed of the vacuum pump in L/s will give the response time to reach 63 % of the total signal. Response times in excess of a few seconds makes leak detection difficult.  
6.3 Test Method C is to be used only when there is no convenient method of connecting the leak detector to the outlet of the high vacuum pump. If a helium leak detector is used and the high vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle as these pumps leave a relatively high percentage of helium in the high vacuum chamber. This will obscure all but large leaks, and the trace gas will quickly saturate the pumps.
SCOPE
1.1 This practice covers procedures for testing and locating the sources of gas leaking at the rate of 1 × 10 −8 Pa m3/s (1 × 10−9  Std cm 3/s)3 or greater. The test may be conducted on any object to be tested that can be evacuated and to the other side of which helium or other tracer gas may be applied.  
1.2 Three test methods are described:  
1.2.1 Test Method A—For the object under test capable of being evacuated, but having no inherent pumping capability.  
1.2.2 Test Method B—For the object under test with integral pumping capability.  
1.2.3 Test Method C—For the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector.  
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 Test Method A—This test method is the most frequently used in leak testing components. Testing of components is correlated to a standard leak, and the actual leak rate is measured. Acceptance is based on the maximum system allowable leakage. For most production needs, acceptance is based on acceptance of parts leaking less than an established leakage rate, which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with the standard leak located at a representative place on the test volume. As the volume tends to be large (>1 m3) and there are often low conductance paths involved, a check of the response time as well as system sensitivity should be made.  
5.2 Test Method B—This test method is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test, or conditioning parts. As with Test Method A, the response time and a system sensitivity check may be required for large volumes.  
5.3 Test Method C—This test method is to be used only when there is no convenient method of connecting the LD to the outlet of the high-vacuum pump. If a helium LD is used and the high-vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle, as these pumps leave a relatively high percentage of helium in the high-vacuum chamber. This will limit the maximum sensitivity that can be obtained.
SCOPE
1.1 This practice covers procedures for testing the sources of gas leaking at the rate of 1 × 10 −8 Pa m3/s (1 × 10−9  standard-cm3/s at 0°C) or greater. These test methods may be conducted on any object that can be evacuated and to the other side of which helium or other tracer gas may be applied. The object must be structurally capable of being evacuated to pressures of 0.1 Pa (approximately 10−3 torr).  
1.2 Three test methods are described;  
1.2.1 Test Method A—For the object under test capable of being evacuated, but having no inherent pumping capability.  
1.2.2 Test Method B—For the object under test with integral pumping capability.  
1.2.3 Test Method C—For the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector (LD).  
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The equipment, test duration, and technique should be determined before commencement of the test based on the required test sensitivity or accuracy (see Annex A1 and Annex A2). If the test is used to certify that the vessel has a minimum specified leakage rate, then the test equipment and test duration should be chosen to have a resolution ten times less than the specification and an accuracy which is four times less than the specification. The test should be designed so that the total pressure change is less than 10 % of the starting pressure. Leak test specifications should specify the vessel test pressure or differential pressure. If the test specification does not specify a test pressure, then a safe test pressure should be used that complies with the applicable safety standards7.
SCOPE
1.1 This practice describes a method for determining the leakage rate of a vessel subject to a positive pressure difference. The technique is based upon evaluation of the change of mass within the test object based on a pressure decay measurement. The pressure decay measurement uses the ideal gas equation of state and the measured pressures, temperatures, and time to determine the mass loss from the vessel. This method does not apply to deformable vessels.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
6.1 This practice is useful for quality control testing and field inspection of piping systems, pipelines, valves, and containers that are expected to retain liquids. It is not sensitive enough for leak testing when toxic or explosive gas is expected to be retained under pressure.
SCOPE
1.1 This practice covers the testing of components for leaks by pressurizing them inside with a liquid.  
1.2 This practice can be used on piping, valves, and containers with welded or fitted sections which can be sealed at their ends and which are designed for internal pressure.  
1.3 Basic procedures are described based on the type of inspection used. These procedures should be limited to finding leakage indications of 4.5 × 10−9 mol/s (1 × 10−4 Std cm3/s)2 or larger.  
1.4 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.  
1.5 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

ABSTRACT
This practice establishes the standard procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. The two types of leaks considered here are Type I, which is pressure to vacuum, and Type II, which is pressure to atmosphere. Three calibration methods are described under each type of reference leak, as follows: Method A—accumulation comparison using a known volume of tracer gas at specified conditions of temperature and pressure as a reference; Method B—accumulation comparison using a reference leak artifact calibrated using Method A; and Method C—direct measurement of leak rate by timing the movement (displacement) of a liquid slug, by the leak, in a capillary tube of known dimensions.
SCOPE
1.1 This practice covers procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. While the uncertainties associated with these procedures will most likely be greater than those obtained via traceable calibration chains (on the order of 10 %), these procedures allow independent means of establishing or verifying the leakage rate from leak artifacts of questionable history, or when traceable leak artifacts are not available.  
1.2 Two types of leaks are considered:  
1.2.1 Type I—Pressure to vacuum.  
1.2.2 Type II—Pressure to atmosphere.  
1.3 Three calibration methods are described under each type of reference leak:  
1.3.1 Method A—Accumulation comparison, using a known volume of gas at specified conditions of temperature and pressure as a reference.  
1.3.2 Method B—Accumulation comparison, using a leak artifact calibrated using Method A.  
1.3.3 Method C—Displacement of a liquid slug, by the leak, in capillary tube of known dimensions.  
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This method is useful for locating and measuring the size of gas leaks either as a quality-control test or as a field-inspection procedure. It can be used to test critical parts or containers that will hold toxic or explosive gases or liquids or as a quick test for other containers.
SCOPE
^SCOPE:
1.1 This test method covers the testing of large single- and double-walled tanks, pressure and vacuum vessels, laminated, lined- or double-walled parts, complex piping systems, flexible containers (such as aircraft fuel tanks), glass-to-metal seals in hybrid packages, and systems that inherently contain or will contain ammonia (such as large tonnage refrigeration systems and fertilizer storage systems).
1.2 This method can be used on piping, valves and containers with welded, fitted, or laminated sections that can be sealed at their ends or between their outer and inner walls and that are designed for internal pressures of 34.5 kPa [5 psig] or greater.
1.3 Basic procedures are described based on the type of inspection used. These procedures should be limited to finding leakage indications of 4.5 × 10−12 mol/s [1 × 10−7 Std cm 3/s] or larger.
1.4 Units—The values stated in Std cm3/s or mol/s are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (For more specific safety precautionary information see 7.4, 8.2, 9.4.1, and 10.3.1).

SIGNIFICANCE AND USE
Practice A—This practice is useful for locating and estimating the size of pressurized gas leaks, either as a quality control test or as a field inspection procedure. It is also valuable as a pretest before other more time consuming and more sensitive leak tests are employed. It should not be used exclusively to locate highly toxic or explosive gas leaks.
Practice B—This practice is useful for locating leaks in systems that are not under pressure or vacuum as either a quality control or a field inspection procedure. It is not useful for estimating the size of a leak. It is also valuable as a pretest before leak tests using pressurized gas methods and more sensitive leak tests are employed.
SCOPE
1.1 Practice A, Pressurization—This practice covers procedures for calibration of ultrasonic instruments, location, and estimated measurements of gas leakage to atmosphere by the airborne ultrasonic technique.  
1.2 In general practice this should be limited to leaks detected by two classifications of instruments, Class I and Class II. Class I instruments should have a minimum detectable leak rate of 6.7 × 10−7 mol/s (1.5 × 10−2 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Class II instruments should have a minimal detectable leak rate of 6.7 × 10−6 mol/s (1.5 × 10−1 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Refer to Guide E432 for additional information.
1.3 Practice B, Ultrasonic Transmitter—For object under test not capable of being pressurized but capable of having ultrasonic tone placed/injected into the test area to act as an ultrasonic leak trace source.
1.3.1 This practice is limited to leaks producing leakage of 6.7 × 10−6 mol/s (1.5 × 10−1 std. cm3/s at 0°C) or greater.
1.4 The values stated in SI units are to be regarded as the standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

ABSTRACT
This guide deals with the selection of the appropriate leak testing method for either leak measurement or location for a particular system being tested (test system), which may consist either of open units or sealed units. The leak testing method may either be dynamic or static, with the dynamic test method requiring shorter time but lesser sensitivity as compared to static techniques. The choice of the appropriate leak testing method shall involve most importantly the optimization of the sensitivity, cost, and reliability of the test. In the case where various testing methods are available for a particular test system, each shall be examined separately and then ranked according to test system sensitivity. However, when determining the sensitivity, it is important to be able to differentiate the sensitivity associated with the instrument used to measure leakage from the sensitivity of the test system followed using the instrument. While the sensitivity of a specific test is dependent on the sensitivity of the instrument used, the choice of instrument and the test system are both influenced by the range of temperatures or pressures and the kinds of fluids involved.
SCOPE
1.1 This guide is intended to assist in the selection of a leak testing method. is supplied as a simplified guide.
1.2 The type of item to be tested or the test system and the method considered for either leak measurement or location are related in the order of increasing sensitivity.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Test Method A—This test method is the most frequently used in leak testing components. Testing of components is correlated to a standard leak, and the actual leak rate is measured. Acceptance is based on the maximum system allowable leakage. For most production needs, acceptance is based on acceptance of parts leaking less than an established leakage rate, which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with the standard leak located at a representative place on the test volume. As the volume tends to be large (>1 m3) and there are often low conductance paths involved, a check of the response time as well as system sensitivity should be made.
Test Method B—This test method is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test, or conditioning parts. As with Test Method A, the response time and a system sensitivity check may be required for large volumes.
Test Method C—This test method is to be used only when there is no convenient method of connecting the LD to the outlet of the high-vacuum pump. If a helium LD is used and the high-vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle, as these pumps leave a relatively high percentage of helium in the high-vacuum chamber. This will limit the maximum sensitivity that can be obtained.
SCOPE
1.1 This practice covers procedures for testing the sources of gas leaking at the rate of 1 × 10−8 Pa m3/s (1 × 10−9 standard-cm3/s at 0°C) or greater. These test methods may be conducted on any object that can be evacuated and to the other side of which helium or other tracer gas may be applied. The object must be structurally capable of being evacuated to pressures of 0.1 Pa (approximately 10−3 torr).
1.2 Three test methods are described;
1.2.1 Test Method A—For the object under test capable of being evacuated, but having no inherent pumping capability.
1.2.2 Test Method B—For the object under test with integral pumping capability.
1.2.3 Test Method C—For the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector (LD).
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Methods A or B are useful in testing hermetically-sealed devices with internal volumes. Maximum acceptable leak rates have been established for microelectronic devices to assure performance characteristics will not be affected by in-leakage of air, water vapor or other contaminants over the projected life expected. Care must be taken to control the bombing pressure, bombing time and dwell time after bombing or the results can vary substantially.
SCOPE
1.1 This practice covers procedures for testing devices that are sealed prior to testing, such as semiconductors, hermetically enclosed relays, pyrotechnic devices, etc., for leakage through the walls of the enclosure. They may be used with various degrees of sensitivity (depending on the internal volume, the strength of the enclosure, the time available for preparation of test, and on the sorption characteristics of the enclosure material for helium). In general practice the sensitivity limits are from 10−10 to 10−6 Pa m3/s (10−9 standard cm3/s to 10−5 standard cm3/s at 0°C) for helium, although these limits may be exceeded by several decades in either direction in some circumstances.
1.2 Two test methods are described:
1.2.1 Test Method A—Test part preparation by bombing.
1.2.2 Test Method B—Test part preparation by prefilling.
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Test Method A is the most frequently used in leak testing components which are structurally capable of being evacuated to pressures of 0.1 Pa (approximately 10−3 torr). Testing of small components can be correlated to calibrated leaks, and the actual leak rate can be measured or acceptance can be based on a maximum allowable leak. For most production needs acceptance is based on acceptance of parts leaking less than an established standard which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with reference leak at a representative place on the test volume. Leak rates are determined by calculating the net gain or loss through a leak in the test part that would cause failure during the expected life of the device.
Test Method B is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test or for conditioning parts. As the volume tends to be large, a check of the response time as well as system sensitivity should be made. Volume of the system in liters divided by the speed of the vacuum pump in L/s will give the response time to reach 63 % of the total signal. Response times in excess of a few seconds makes leak detection difficult.
Test Method C is to be used only when there is no convenient method of connecting the leak detector to the outlet of the high vacuum pump. If a helium leak detector is used and the high vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle as these pumps leave a relatively high percentage of helium in the high vacuum chamber. This will obscure all but large leaks, and the trace gas will quickly saturate the pumps.
SCOPE
1.1 This practice covers procedures for testing and locating the sources of gas leaking at the rate of 1 × 10−8 Pa m3/s (1 × 10−9 Std cm 3/s) or greater. The test may be conducted on any object to be tested that can be evacuated and to the other side of which helium or other tracer gas may be applied.
1.2 Three test methods are described:
1.2.1 Test Method A—For the object under test capable of being evacuated, but having no inherent pumping capability.  
1.2.2 Test Method B—For the object under test with integral pumping capability.
1.2.3 Test Method C—For the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector.
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
These test methods are useful for locating and estimating the size of pressurized gas leaks, either as quality control tests or as field inspection procedures. Also, they are valuable as pretests before other more time consuming and more sensitive leak tests are employed. These test methods are semi-quantitative techniques used to locate leaks but cannot be used to quantify except for approximation. These test methods may be used in an accept-reject test mode.
SCOPE
1.1 This practice covers procedures for detecting the sources of gas leaking at the rate of 1 × 10–5 Pa m3/s (1 × 10–4 standard cm3/s) or greater. The tests may be conducted on any object that can be pressurized with a tracer gas that is detectable by a thermal conductivity detector. The test sensitivity will vary widely depending on the tracer gas used.
1.2 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Test Method A is frequently used to test large systems and complex piping installations that can be filled with a trace gas. Helium is normally used. The test method is used to locate leaks but cannot be used to quantify except for approximation. Care must be taken to provide sufficient ventilation to prevent increasing the helium background at the test site. Results are limited by the helium background and the percentage of the leaking trace gas captured by the probe.
Test Method B is used to increase the concentration of trace gas coming through the leak by capturing it within an enclosure until the signal above the helium background can be detected. By introducing a calibrated leak into the same volume for a recorded time interval, leak rates can be measured.
SCOPE
1.1 This practice covers procedures for testing and locating the sources of gas leaking at the rate of 1 × 10−7 Pa m3/s (1 × 10−8 Std cm3/s) or greater. The test may be conducted on any device or component across which a pressure differential of helium or other suitable tracer gas may be created, and on which the effluent side of the leak to be tested is accessible for probing with the mass spectrometer sampling probe.
1.2 Two test methods are described:
1.2.1 Test Method A—Direct probing, and
1.2.2 Test Method B—Accumulation.
1.3 Units—The values stated in either SI or std-cc/sec units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
The immersion technique is frequently used to locate leaks in sealed containers. Leaks in a container can be seen independently. Leak size can be approximated by the size of the bubble. It is not suitable for measurement of total system leakage.
The liquid film technique is widely applied to components and systems that can not easily be immersed and is used to rapidly locate leaks. An approximation of leak size can be made based on the type of bubbles formed, but the technique is not suitable for measuring leakage rate. It can be used with a vacuum box to test vessels which cannot be pressurized or where only one side is accessible.
Accuracy—This practice is not intended to measure leakage rates, but to locate leaks on a go, no-go basis. Their accuracy for locating leaks of 4.5 × 10−10 mol/s (1 × 10−4 Std cm3/s) and larger is ±5 %. Accuracy for locating smaller leaks depends upon the skill of the operator.
Repeatability—On a go, no-go basis, duplicate tests by the same operator should not vary by more than ±5 % for leaks of 4.5 × 10−9 mol/s (1 × 10−4 Std cm3/s).  
Reproducibility—On a go, no-go basis, duplicate tests by other trained operators should not vary by more than 10 % for leaks of 4.5 × 10−9 mol/s (1 × 10−4 Std cm3/s) and larger.
SCOPE
1.1 This practice covers procedures for detecting or locating leaks, or both, by bubble emission techniques. A quantitative measure is not practical. The normal limit of sensitivity for this test method is 4.5 × 10−10 mol/s (1 × 10−5 Std cm3/s).  
1.2 Two techniques are described:
1.2.1 Immersion technique, and
1.2.2 Liquid application technique.
Note 1—Additional information is available in ASME Boiler and Pressure Vessel Code, Section V, Article 10-Leak Testing, and Guide E479.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Test Method A is the most frequently used in leak testing components which are structurally capable of being evacuated to pressures of 0.1 Pa (approximately 10−3 torr). Testing of small components can be correlated to calibrated leaks, and the actual leak rate can be measured or acceptance can be based on a maximum allowable leak. For most production needs acceptance is based on acceptance of parts leaking less than an established standard which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with reference leak at a representative place on the test volume. Leak rates are determined by calculating the net gain or loss through a leak in the test part that would cause failure during the expected life of the device.
Test Method B is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test or for conditioning parts. As the volume tends to be large, a check of the response time as well as system sensitivity should be made. Volume of the system in liters divided by the speed of the vacuum pump in L/s will give the response time to reach 63 % of the total signal. Response times in excess of a few seconds makes leak detection difficult.
Test Method C is to be used only when there is no convenient method of connecting the leak detector to the outlet of the high vacuum pump. If a helium leak detector is used and the high vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle as these pumps leave a relatively high percentage of helium in the high vacuum chamber. This will obscure all but large leaks, and the trace gas will quickly saturate the pumps.
SCOPE
1.1 These test methods cover procedures for testing and locating the sources of gas leaking at the rate of 4.5 10 14 mol/s (1 109 Std cm 3/s) or greater. The test may be conducted on any object to be tested that can be evacuated and to the other side of which helium or other tracer gas may be applied.
1.2 Three test methods are described:
1.2.1 Test Method A - For the object under test capable of being evacuated, but having no inherent pumping capability.
1.2.2 Test Method B - For the object under test with integral pumping capability.
1.2.3 Test Method C - For the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. A specific hazard statement can be found in .

SIGNIFICANCE AND USE
This method is useful for locating and measuring the size of gas leaks either as a quality-control test or as a field-inspection procedure. It can be used to test critical parts or containers that will hold toxic or explosive gases or liquids or as a quick test for other containers.
SCOPE
1.1 This test method covers the testing of large single- and double-walled tanks, pressure and vacuum vessels, laminated, lined- or double-walled parts, complex piping systems, flexible containers (such as aircraft fuel tanks), glass-to-metal seals in hybrid packages, and systems that inherently contain or will contain ammonia (such as large tonnage refrigeration systems and fertilizer storage systems).
1.2 This method can be used on piping, valves and containers with welded, fitted, or laminated sections that can be sealed at their ends or between their outer and inner walls and that are designed for internal pressures of 34.5 kPa (5 psig) or greater.
1.3 Basic procedures are described based on the type of inspection used. These procedures should be limited to finding leakage indications of 4.5 x 10-12 mol/s (1 x 10-7 Std cm 3/s) or larger.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (For more specific safety precautionary information see 7.4, 8.2, 9.4.1, and ) 103.1.

SIGNIFICANCE AND USE
Test Method A is frequently used to test large systems and complex piping installations that can be filled with a trace gas. Helium is normally used. The test method is used to locate leaks but cannot be used to quantify except for approximation. Care must be taken to provide sufficient ventilation to prevent increasing the helium background at the test site. Results are limited by the helium background and the percentage of the leaking trace gas captured by the probe.
Test Method B is used to increase the concentration of trace gas coming through the leak by capturing it within an enclosure until the signal above the helium background can be detected. By introducing a calibrated leak into the same volume for a recorded time interval, leak rates can be measured.
SCOPE
1.1 These test methods cover procedures for testing and locating the sources of gas leaking at the rate of 4.5 x 10 13 mol/s (1 x 108 Std cm 3/s) or greater. The test may be conducted on any device or component across which a pressure differential of helium or other suitable tracer gas may be created, and on which the effluent side of the leak to be tested is accessible for probing with the mass spectrometer sampling probe.
1.2 Two test methods are described:
1.2.1 Test Method A - Direct probing, and
1.2.2 Test Method B - Accumulation.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Test Method A—This test method is the most frequently used in leak testing components. Testing of components is correlated to a standard leak, and the actual leak rate is measured. Acceptance is based on the maximum system allowable leakage. For most production needs, acceptance is based on acceptance of parts leaking less than an established leakage rate, which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with the standard leak located at a representative place on the test volume. As the volume tends to be large (>1 m3) and there are often low conductance paths involved, a check of the response time as well as system sensitivity should be made.
Test Method B—This test method is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test, or conditioning parts. As with Test Method A, the response time and a system sensitivity check may be required for large volumes.
Test Method C—This test method is to be used only when there is no convenient method of connecting the LD to the outlet of the high-vacuum pump. If a helium LD is used and the high-vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle, as these pumps leave a relatively high percentage of helium in the high-vacuum chamber. This will limit the maximum sensitivity that can be obtained.
SCOPE
1.1 These test methods cover procedures for testing the sources of gas leaking at the rate of 4.4 10 14 moles/s (1 109 standard-cm 3/s at 0C) or greater. These test methods may be conducted on any object that can be evacuated and to the other side of which helium or other tracer gas may be applied. The object must be structurally capable of being evacuated to pressures of 0.1 Pa (approximately 103 torr).
1.2 Three test methods are described;
1.2.1 Test Method AFor the object under test capable of being evacuated, but having no inherent pumping capability.
1.2.2 Test Method BFor the object under test with integral pumping capability.
1.2.3 Test Method CFor the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector (LD).
1.3 The values stated in SI units are to be regarded as standard. The values given in brackets are for information only.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Methods A or B are useful in testing hermetically-sealed devices with internal volumes. Maximum acceptable leak rates have been established for microelectronic devices to assure performance characteristics will not be affected by in-leakage of air, water vapor or other contaminants over the projected life expected. Care must be taken to control the bombing pressure, bombing time and dwell time after bombing or the results can vary substantially.
SCOPE
1.1 These test methods cover procedures for testing devices that are sealed prior to testing, such as semiconductors, hermetically enclosed relays, pyrotechnic devices, etc., for leakage through the walls of the enclosure. They may be used with various degrees of sensitivity (depending on the internal volume, the strength of the enclosure, the time available for preparation of test, and on the sorption characteristics of the enclosure material for helium). In general practice the sensitivity limits are from 4.4 1015 to 4.4 10 11 moles/s (109 standard cm3/s to 105 standard cm3/s at 0C) for helium, although these limits may be exceeded by several decades in either direction in some circumstances.
1.2 Two test methods are described:
1.2.1 Test Method ATest part preparation by bombing.
1.2.2 Test Method BTest part preparation by prefilling.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
The immersion technique is frequently used to locate leaks in sealed containers. Leaks in a container can be seen independently. Leak size can be approximated by the size of the bubble. It is not suitable for measurement of total system leakage.
The liquid film technique is widely applied to components and systems that can not easily be immersed and is used to rapidly locate leaks. An approximation of leak size can be made based on the type of bubbles formed, but the technique is not suitable for measuring leakage rate. It can be used with a vacuum box to test vessels which cannot be pressurized or where only one side is accessible.
SCOPE
1.1 This test method covers procedures for detecting or locating leaks, or both, by bubble emission techniques. A quantitative measure is not practical. The normal limit of sensitivity for this test method is 4.5 X 10-10 mol/s (1 X 10-5 Std cm3/s).²
1.2 Two techniques are described:
1.2.1 Immersion technique, and
1.2.2 Liquid application technique.
Note 1—Additional information is available in ASME Boiler and Pressure Vessel Code, Section V, Article 10-Leak Testing, and Guide E 479.
1.3 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
These test methods are useful for locating and estimating the size of pressurized gas leaks, either as quality control tests or as field inspection procedures. Also, they are valuable as pretests before other more time consuming and more sensitive leak tests are employed. These test methods are semi-quantitative techniques used to locate leaks but cannot be used to quantify except for approximation. These test methods may be used in an accept-reject test mode.
SCOPE
1.1 These test methods cover procedures for detecting the sources of gas leaking at the rate of 4.5 X 10&sup-9; mol/s (1 X 10&sup/4; standard cm³/s) or greater. The tests may be conducted on any object that can be pressurized with a tracer gas that is detectable by a thermal conductivity detector. The test sensitivity will vary widely depending on the tracer gas used.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Test Method A—This test method is useful for locating and estimating the size of pressurized gas leaks, either as a quality control test or as a field inspection procedure. It is also valuable as a pretest before other more time consuming and more sensitive leak tests are employed. It should not be used exclusively to locate highly toxic or explosive gas leaks.
Test Method B—This test method is useful for locating leaks in systems that are not under pressure or vacuum as either a quality control or a field inspection procedure. It is not useful for estimating the size of a leak. It is also valuable as a pretest before leak tests using pressurized gas methods and more sensitive leak tests are employed.
SCOPE
1.1 Test Method A, Pressurization— This test method covers procedures for calibration of ultrasonic instruments, location, and estimated measurements of gas leakage to atmosphere by the airborne ultrasonic technique.²
1.2 In general practice this should be limited to leaks detected by two classifications of instruments, Class I and Class II. Class I instruments should have a minimum detectable leak rate of 6.7 10 7 mol/s (1.5 10 2 std. cm3/s at 0C) or more for the pressure method of gas leakage to atmosphere. Class II instruments should have a minimal detectable leak rate of 6.7 106 mol/s (1.5 10 1 std. cm3/s at 0C) or more for the pressure method of gas leakage to atmosphere. Refer to Guide E 432 for additional information.
1.3 Test Method B, Ultrasonic TransmitterFor object under test not capable of being pressurized but capable of having ultrasonic tone placed/injected into the test area to act as an ultrasonic leak trace source.
1.3.1 This test method is limited to leaks producing leakage of 6.7 106 mol/s (1.5 10 1 std. cm3/s at 0C) or greater.
1.4 The values stated in SI units are to be regarded as the standard.
1.5This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

ABSTRACT
This guide deals with the selection of the appropriate leak testing method for either leak measurement or location for a particular system being tested (test system), which may consist either of open units or sealed units. The leak testing method may either be dynamic or static, with the dynamic test method requiring shorter time but lesser sensitivity as compared to static techniques. The choice of the appropriate leak testing method shall involve most importantly the optimization of the sensitivity, cost, and reliability of the test. In the case where various testing methods are available for a particular test system, each shall be examined separately and then ranked according to test system sensitivity. However, when determining the sensitivity, it is important to be able to differentiate the sensitivity associated with the instrument used to measure leakage from the sensitivity of the test system followed using the instrument. While the sensitivity of a specific test is dependent on the sensitivity of the instrument used, the choice of instrument and the test system are both influenced by the range of temperatures or pressures and the kinds of fluids involved.
SCOPE
1.1 This guide is intended to assist in the selection of a leak testing method. is supplied as a simplified guide.
1.2 The type of item to be tested or the test system and the method considered for either leak measurement or location are related in the order of increasing sensitivity.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

ABSTRACT
This practice establishes the standard procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. The two types of leaks considered here are Type I, which is pressure to vacuum, and Type II, which is pressure to atmosphere. Three calibration methods are described under each type of reference leak, as follows: Method A—accumulation comparison using a known volume of tracer gas at specified conditions of temperature and pressure as a reference; Method B—accumulation comparison using a reference leak artifact calibrated using Method A; and Method C—direct measurement of leak rate by timing the movement (displacement) of a liquid slug, by the leak, in a capillary tube of known dimensions.
SCOPE
1.1 This practice covers procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. While the uncertainties associated with these procedures will most likely be greater than those obtained via traceable calibration chains (on the order of 10 %), these procedures allow independent means of establishing or verifying the leakage rate from leak artifacts of questionable history, or when traceable leak artifacts are not available.
1.2 Two types of leaks are considered:
1.2.1 Type I—Pressure to vacuum.
1.2.2 Type II—Pressure to atmosphere.
1.3 Three calibration methods are described under each type of reference leak:
1.3.1 Method A—Accumulation comparison, using a known volume of gas at specified conditions of temperature and pressure as a reference.
1.3.2 Method B—Accumulation comparison, using a leak artifact calibrated using Method A.
1.3.3 Method C—Displacement of a liquid slug, by the leak, in capillary tube of known dimensions.
1.4 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be appropriate.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 These test methods cover procedures for testing and locating the sources of gas leaking at the rate of 4.5 X 10 -13  mol/s (1 X 10 -8  Std cm3 /s) or greater. The test may be conducted on any device or component across which a pressure differential of helium or other suitable tracer gas may be created, and on which the effluent side of the leak to be tested is accessible for probing with the mass spectrometer sampling probe.  
1.2 Two test methods are described:  
1.2.1 Test Method A -Direct probing, and  
1.2.2 Test Method B -Accumulation.
1.3  This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 These test methods cover procedures for testing and locating the sources of gas leaking at the rate of 4.5 X 10 -14  mol/s (1 X 10 -9  Std cm3/s) or greater. The test may be conducted on any object to be tested that can be evacuated and to the other side of which helium or other tracer gas may be applied.  
1.2 Three test methods are described:  
1.2.1 Test Method A -For the object under test capable of being evacuated, but having no inherent pumping capability.  
1.2.2 Test Method B -For the object under test with integral pumping capability.  
1.2.3 Test Method C -For the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. A specific hazard statement can be found in 19.2.

SCOPE
1.1 This practice covers procedures for testing and locating the sources of gas leaking at the rate of 2.2 X 10 -14 mol/s (5 X 10 -10  Std cm3/s).  The test may be conducted on any device or component across which a pressure differential of halogen tracer gas may be created, and on which the effluent side of the area to be leak tested is accessible for probing with the halogen leak detector.  
1.2 Five methods are described:  
1.2.1  Method A -Direct probing with no significant halogen contamination in the atmosphere.  
1.2.2 Method B -Direct probing with significant halogen contamination in the atmosphere.  
1.2.3  Method C -Shroud test.  
1.2.4 Method D -Air-curtain shroud test.  
1.2.5 Method E -Accumulation test.  
1.3 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate.
1.4  This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the testing of components for leaks by pressurizing them inside with a liquid.  
1.2 This test method can be used on piping, valves, and containers with welded or fitted sections which can be sealed at their ends and which are designed for internal pressure.  
1.3 Basic procedures are described based on the type of inspection used. These procedures should be limited to finding leakage indications of 4.5 X 10 -9  mol/s (1 X 10 -4  Std cm /s)  or larger.  
1.4 The values stated in SI units are to be regarded as the standard.  
1.5 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers procedures for detecting or locating leaks, or both, by bubble emission techniques. A quantitative measure is not practical. The normal limit of sensitivity for this test method is 4.5 X 10 -10  mol/s (1 X 10 -5  Std cm /s).  
1.2 Two techniques are described:  
1.2.1 Immersion technique, and  
1.2.2 Liquid application technique. Note-Additional information is available in ASME Boiler and Pressure Vessel Code, Section V, Article 10-Leak Testing, and Guide E479.
1.3 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the testing of large single- and double-walled tanks, pressure and vacuum vessels, laminated, lined- or double-walled parts, complex piping systems, flexible containers (such as aircraft fuel tanks), glass-to-metal seals in hybrid packages, and systems that inherently contain or will contain ammonia (such as large tonnage refrigeration systems and fertilizer storage systems).  
1.2 This method can be used on piping, valves and con- tainers with welded, fitted, or laminated sections that can be sealed at their ends or between their outer and inner walls and that are designed for internal pressures of 34.5 kPa (5 psig) or greater.  
1.3 Basic procedures are described based on the type of inspection used. These procedures should be limited to find- ing leakage indications of 4.5 X 10  12  mol/s (1 X 10   Std cm /s)  or larger.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (For more specific safety precautionary information see 7.4, 8.2, 9.4.1, and 10.3.1).

SIGNIFICANCE AND USE
This test method is useful for quality control testing and field inspection of piping systems, pipelines, valves, and containers that are expected to retain liquids. It is not sensitive enough for leak testing when toxic or explosive gas is expected to be retained under pressure.
SCOPE
1.1 This test method covers the testing of components for leaks by pressurizing them inside with a liquid.
1.2 This test method can be used on piping, valves, and containers with welded or fitted sections which can be sealed at their ends and which are designed for internal pressure.
1.3 Basic procedures are described based on the type of inspection used. These procedures should be limited to finding leakage indications of 4.5 X 10-9 mol/s (1 X 10-4 Std cm3/s)° or larger.
1.4 The values stated in SI units are to be regarded as standard.
1.5 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This standard is intended as a guide. It enumerates factors to be considered in preparing a definitive specification for maximum permissible gas leakage of a component, device, or system. The guide relates and provides examples of data for the preparation of leak testing specifications. It is primarily applicable for use in specifying halogen leak testing methods.  
1.2 Two types of specifications are described:  
1.2.1 Operational specifications (OS), and  
1.2.2 Testing specifications (TS):  
1.2.2.1 Total, and  
1.2.2.2 Each leak.  
1.3 This standard does not purport to address the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.