Standard Specification for Temperature Monitoring Equipment

ABSTRACT
This specification covers the requirements for temperature monitoring equipment for use in general applications. Such equipment shall be comprised of a temperature sensor in combination with a signal conditioner, a power supply, and a test device. Temperature sensors covered by this specification are divided into thermocouples, which measure direct or differential temperature, and resistance thermometers, which measure temperature changes based on changes in resistance of sensor element exposed to temperature. Each of these types of sensors may further be classified as follows. Thermocouples can be classified into three classes based on materials and temperature ranges: base metal, noble metal, and refractory metal. Resistance thermometers, on the other hand, can be classified according to the type of sensor element used: metal sensor element (resistance temperature detector or RTD) or semiconductor sensor element (thermistor). RTDs are available in various design configurations including averaging, annular, and combination RTD-thermocouple, while thermistors are classified based on the configuration of the semiconductor sensor element: bead, disc, washer, or rod. Qualification test shall be performed on the equipment and shall comply with the physical property and performance requirements specified.
SCOPE
1.1 This specification covers the requirements for equipment intended to provide control input and monitoring of temperatures in general applications. Equipment described in this specification includes temperature indicators, signal conditioners and power supplies, and temperature sensors such as thermocouples and resistance temperature element assemblies.
1.2 Special requirements for Naval shipboard applications are included in the Supplementary Requirements section.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

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Publication Date
30-Nov-2003
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ASTM F2362-03 - Standard Specification for Temperature Monitoring Equipment
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
Designation: F 2362 – 03
Standard Specification for
Temperature Monitoring Equipment
This standard is issued under the fixed designation F 2362; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4.2 Thermocouples—Thermocouples are constructed in a
variety of designs to provide measurement of direct or differ-
1.1 This specification covers the requirements for equip-
ential temperature. Thermocouples are commonly installed
ment intended to provide control input and monitoring of
using a thermowell which protects the thermocouple but also
temperatures in general applications. Equipment described in
delays the rapid response time characteristic of thermocouples.
this specification includes temperature indicators, signal con-
4.2.1 Principle of Operation—Most thermocouples utilize
ditioners and power supplies, and temperature sensors such as
two wires fabricated from dissimilar metals joined at one end
thermocouples and resistance temperature element assemblies.
to form a measuring junction that is exposed to the process
1.2 Special requirements for Naval shipboard applications
medium being measured. The other ends of the wires are
are included in the Supplementary Requirements section.
usually terminated at a measuring instrument which forms a
1.3 The values stated in SI units are to be regarded as the
reference junction. When the two junctions are exposed to
standard. The values given in parentheses are for information
different temperatures, electrical current will flow through the
only.
circuit (Seebeck Effect). The measurement of millivoltage
2. Referenced Documents resulting from the current is proportional to the temperature
being sensed.
2.1 ASTM Standards:
4.2.2 Types of Thermocouples—Thermocouples can be di-
D 3951 Practice for Commercial Packaging
vided into functional classes by materials and therefore,
E 344 Terminology Relating to Thermometry and Hydrom-
temperature ranges. The three classes are base metal, noble
etry
metal, and refractory metal. Although many types are com-
3. Terminology
monlyusedinindustrialapplications,theInstrumentSocietyof
America (ISA) has assigned letter designations to seven types.
3.1 Definitions—Definitions of terminology shall be in ac-
By convention, the practice of using a slash mark to separate
cordance with Terminology E 344.
the materials of each thermocouple wire is widely accepted.
4. Classification
Likewise, the order in which the materials appear also denotes
polarity of the wires; positive/negative when the measuring
4.1 General—Temperature measuring devices are generally
junction is at a higher temperature than the reference junction.
classified as either temperature sensors or thermometers. Ther-
The following are examples of typical thermocouples:
mometers are not covered by this specification. Temperature
sensors are classified by design and construction. Sensors may Class Type Materials Temperature (max)
Base metal J Iron/constantan 1000°C (1832°F)
also be classified by the manner of response, basically me-
Base metal T Copper/constantan 1000°C (1832°F)
chanical or electrical, to a change in temperature. Mechanical
Base metal K Chromel/Alumel 1000°C (1832°F)
Base metal E Chromel/constantan 1000°C (1832°F)
response is characterized by some mechanical action as tem-
Base metal --- Alloys of copper, nickel, iron, chromium, 1000°C (1832°F)
perature changes. Electrical response is characterized by the
manganese, aluminum, and other metals
production or change of an electrical signal or property as
Noble metal --- Various noble metals 2000°C (3632°F)
Refractory --- Tungsten-rhenium, tantalum, molybdenum, 2600°C (4712°F)
temperature changes. The following describes the most com-
metal and their alloys
mon types of sensors:
4.3 Resistance Temperature Measuring Devices—
Resistance thermometers measure changes in temperature
This specification is under the jurisdiction of ASTM Committee F25 on Ships
based on changes in resistance of the sensor element exposed
and Marine Technology and is the direct responsibility of Subcommittee F25.10 on
to the temperature. Two common types are resistance tempera-
Electrical.
Current edition approved Dec. 1, 2003. Published January 2004.
ture detectors which have metal sensor elements and ther-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
mistors which have semiconductor sensor elements.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F2362–03
4.3.1 Resistance Temperature Detectors (RTDs)—An RTD 7.1.2 Power Supply—The power supply shall provide exci-
consists of sensor which uses a metal wire or fiber which tation energy to the signal conditioner and sensor.
responds to changes in temperature by changing its resistance. 7.1.3 Test Device—A test device shall be furnished to
The sensor is connected to a readout via a bridge circuit or provide a calibrated test signal used for calibrating the equip-
other means of translating the resistance to a temperature ment.
value. 7.2 Size and Weight Considerations—Adimensional outline
4.3.1.1 Types of RTDs—RTD designs include averaging of the temperature monitoring equipment showing overall and
RTDs, annular RTDs, and combination RTD-thermocouples. principle dimensions in sufficient detail to establish space
Averaging RTDs are characterized by a long resistance ele- requirements in all directions necessary for installation and
ment.Annular RTDs have sensors that are designed to provide servicing will greatly assist proper selection. In many applica-
a tight fit within the inner walls of thermowells. Combination tions weight is a critical limitation.
RTD-thermocouples have both an RTD and a thermocouple 7.3 General Features—Requirements for general features
housed in the same sheath. shall be specified. General features consist of the following:
4.3.2 Thermistors—Thermistors are made of solid semicon- 7.3.1 Output,
ductor materials, usually complex metal oxides, that have a 7.3.2 Equipment range,
high coefficient of resistance. Thermistors are available with 7.3.3 Adjustments,
positiveandnegativetemperaturecoefficientsofresistanceand 7.3.4 Failsafe output,
are usually designated PTC and NTC thermistors, respectively. 7.3.5 Isolation,
The temperature range for typical thermistors is 100 to 300°C 7.3.6 Enclosure,
(212 to 572°F). 7.3.7 Power supply requirements, and
4.3.2.1 Types of Thermistors—Thermistors are classed by 7.3.8 Cable entrance and connection.
the configuration of the semiconductor material. Common
types are the bead, disc, washer, and rod thermistors. Leads are 8. Performance Requirements
attachedtosemiconductormaterials,exceptwheremetalplated
8.1 Service Life—The purchaser may have a minimum
faces are used for contact to complete the circuit.
specified service life requirement. Critical service life require-
ments shall be specified in the acquisition requirements.
5. Ordering Information
8.2 Performance Considerations—Certain performance
5.1 The purchaser should provide the manufacturer with all
characteristics may be deemed critical to the intended or
of the pertinent application data outlined in the acquisition
desired function of temperature monitoring equipment. Perfor-
requirements.
mance tolerances are usually expressed in percent of equip-
5.2 Acquisition Requirements—Acquisition documents
ment span. The following performance characteristics and
should specify the following:
environmentalexposuresshouldbetailoredtoeachpurchaser’s
5.2.1 Title, number and date of this specification,
intended application:
5.2.2 Classification required,
8.2.1 Accuracy,
5.2.3 Quantity of units required,
8.2.2 Repeatability,
5.2.4 Type of enclosure mounting,
8.2.3 Threshold and deadband,
5.2.5 Power requirements,
8.2.4 Ripple,
5.2.6 Equipment temperature ranges,
8.2.5 Warm-up time,
5.2.7 Size or weight limitations,
8.2.6 Input resistance,
5.2.8 Disposition of qualification test samples,
8.2.7 Supply voltage or frequency, or both,
5.2.9 Product marking requirements, and
8.2.8 Temperature error,
5.2.10 Special preservation, packaging, packing and mark-
8.2.9 Response time,
ing requirements.
8.2.10 Temperature,
8.2.11 Insulation resistance,
6. Materials and Manufacture
8.2.12 Vibration, and
6.1 TemperatureSensors—Thematerialsforallwettedparts
8.2.13 Shock.
shall be selected for long term compatibility with the process
medium.
9. Workmanship, Finish and Appearance
7. Physical Properties 9.1 Finish and Appearance—Any special surface finish and
appearance requirements shall be specified in the acquisition
7.1 Description—The equipment specified herein in con-
requirements.
junction with the thermocouples or resistance temperature
measuring elements comprise a temperature instrument. The
10. Number of Tests and Retests
temperature monitoring equipment may consist of the follow-
ing units and may be built integrally together and housed in the 10.1 Test Specimen—The number of test specimens to be
same enclosure: subjected to qualification testing shall depend on the sensor
7.1.1 Signal Conditioner—Thesignalconditioner shall con- design. If each range is covered by a separate and distinct
vert the sensing element output to a continuous linear analog design, a test specimen for each range may require testing. In
signal directly proportional to temperature. instances where a singular design series may cover multiple
F2362–03
ranges and types, only three test specimens may need to be 13. Certification
tested provided the electrical and mechanical similarities are
13.1 When specified in the purchase order or contract, the
approved by the purchaser. In no case, however, should less
purchaser shall be furnished certification that samples repre-
than three units, one unit each representing low , medium, and
sentingeachlothavebeeneithertestedorinspectedasdirected
high ranges, be tested, regardless of design similarity.
inthisspecificationandtherequirementshavebeenmet.When
specified in the purchase order or contract, a report of the test
11. Test Data
results shall be furnished.
11.1 Test Data—All test data shall remain on file at the
14. Product Marking
manufacturer’s facility for review by the purchaser upon
request. It is recommended that test data be retained in the
14.1 Purchaser specified product marking shall be listed in
manufacturer’s files for at least three years, or a period of time
the acquisition requirements.
acceptable to the purchaser and manufacturer.
15. Packaging and Package Marking
12. Inspection
15.1 Packaging of Product for Delivery—Productshouldbe
12.1 Classification of Inspections—The inspection require-
packaged for shipment in accordance with Practice D 3951.
ments specified herein are classified as follows:
15.2 Any special preservation, packaging, or package mark-
12.1.1 Qualification testing, and
ing requirements for shipment or storage shall be identified in
12.1.2 Quality conformance testing.
the acquisition requirements.
12.2 Qualification Testing—Qualification test requirements
16. Quality Assurance Provisions
shall be specified where applicable. Qualification test methods
should be identified for each design and performance charac-
16.1 Warranty:
teristic specified. Test report documentation requirements
16.1.1 Responsibility for Warranty—Unless otherwise
should also be specified.
specified, the manufacturer is responsible for the following:
12.3 Quality Conformance Testing—Quality conformance
16.1.1.1 All materials used to produce a unit, and
testing is accomplished when qualification testing was satisfied
16.1.1.2 Manufacturer will warrant his product to be free
by a previous acquisition or product has demonstrated reliabil-
from defect of workmanship to produce the unit.
ity in similar applications. Quality conformance testing is
17. Keywords
usually less intensive than qualification, often verifying that
samples of a production lot meet a few critical performance 17.1 resistance temperature detector (RTD); thermistor;
requirements. thermocouple
SUPPLEMENTARY REQUIREMENTS
TEMPERATURE MONITORING EQUIPMENT (NAVAL SHIPBOARD USE)
The following supplementary requirements established for U.S. Naval shipboard application shall
apply when specified in the contract or purchase order. When there is conflict between the standard
(ASTM F 2362) and this supplement, the requirements of this supplement shall take precedence for
equipment acquired by this supplement. This document supercedes MIL-T-15377, Temperature
Monitor Equipment, Naval Shipboard, for new ship construction.
S1. Scope sensing elements. Temperature monitoring equipment shall
actuate external audible alarms specified herein.
S1.1 Thissupplementcoverstemperaturemonitoringequip-
S1.3 Selective Temperature Readout Equipment—Selective
ment which continuously monitors and selectively indicates, at
temperature readout equipment, in conjunction with tempera-
a central location, a number of temperatures at remote equip-
ture sensor assemblies and interconnecting cabling, comprise a
ment locations on board naval ships.
temperature measuring system. In order to enable operating
S1.2 Monitoring Equipment—Monitoring equipment, in
personnel to measure a number of temperatures at remote
conjunction with the temperature sensor assemblies and inter-
points, the system shall enable the operator to manually select
connecting cabling, comprise a temperature measuring and
the desired point to be measured, convert the selected tempera-
alarm system. In order to warn operating personnel of abnor-
ture sensor output to a signal proportional to temperature, and
mal temperature conditions, the system shall energize an
displaythissignalonametercalibratedintemperature°C(°F).
audible and visual alarm when the temperature at a particular
Readout of temperatures shall be accomplished by measuring
location is below or above a preset limit. Monitoring of the output of thermocouples or by measuring the signal output
temperatures shall be accomplished by measuring the electro- due to changes in resistance of temperature sensing elements.
motive force (emf) output of thermocouples or by measuring
S1.4 The U.S. Government preferred system of measure-
the signal output due to changes in resistance of temperature ment is the metric SI system. However, since this item was
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