ASTM E3022-18

Standard Practice for Measurement of Emission Characteristics and Requirements for LED UV-A Lamps Used in Fluorescent Penetrant and Magnetic Particle Testing

SIGNIFICANCE AND USE
4.1 UV-A lamps are used in fluorescent penetrant and magnetic particle examination processes to excite fluorophores (dyes or pigments) to maximize the contrast and detection of discontinuities. The fluorescent dyes/pigments absorb energy from the UV-A radiation and re-emit visible light when reverting to its ground state. This excitation energy conversion allows fluorescence to be observed by the human eye.  
4.2 The emitted spectra of UV-A lamps can greatly affect the efficiency of dye/pigment fluorescent excitation.  
4.3 Some high-intensity UV-A lamps can produce irradiance greater than 10 000 μW/cm2 at 15 in. (381 mm). All high-intensity UV-A light sources can cause fluorescent dye fade and increase exposure of the inspector’s unprotected eyes and skin to high levels of damaging radiation.  
4.4 UV-A lamps can emit unwanted visible light and harmful UV radiation if not properly filtered. Visible light contamination above 400 nm can interfere with the inspection process and must be controlled to minimize reflected glare and maximize the contrast of the indication. UV-B and UV-C contamination must also be eliminated to prevent exposure to harmful radiation.  
4.5 Pulse Width Modulation (PWM) and Pulse Firing (PF) of UV-A LED circuits are not permitted.
Note 1: The ability of existing UV-A radiometers and spectroradiometers to accurately measure the irradiance of pulse width modulated or pulsed fired LEDs and the effect of pulsed firing on indication detectability is not well understood.
SCOPE
1.1 This practice covers the procedures for testing the performance of ultraviolet A (UV-A), light emitting diode (LED) lamps used in fluorescent penetrant and fluorescent magnetic particle testing (see Guides E709 and E2297, and Practices E165/E165M, E1208, E1209, E1210, E1219, E1417/E1417M and E1444).2 This specification also includes reporting and performance requirements for UV-A LED lamps.  
1.2 These tests are intended to be performed only by the manufacturer to certify performance of specific lamp models (housing, filter, diodes, electronic circuit design, optical elements, cooling system, and power supply combination) and also includes limited acceptance tests for individual lamps delivered to the user. This test procedure is not intended to be utilized by the end user.  
1.3 This practice is only applicable for UV-A LED lamps used in the examination process. This practice is not applicable to mercury vapor, gas-discharge, arc or luminescent (fluorescent) lamps or light guides (for example, borescope light sources).  
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.

General Information

• Status: Published
• Publication Date: 30-Jun-2018
• ICS: 19.100 - Non-destructive testing
• ICS: 29.140.01 - Lamps in general
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.03 - Liquid Penetrant and Magnetic Particle Methods

Relations

• Refers: ASTM E1316-24 - Standard Terminology for <?Pub Dtl?>Nondestructive Examinations
• Effective Date: 01-Feb-2024
• Refers: ASTM E1316-19b - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Dec-2019
• Refers: ASTM E1316-19 - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Mar-2019
• Refers: ASTM E1316-18 - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Jan-2018
• Refers: ASTM E1316-17a - Standard Terminology for Nondestructive Examinations
• Effective Date: 15-Jun-2017
• Refers: ASTM E1316-17 - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Feb-2017
• Refers: ASTM E1316-16a - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Aug-2016
• Refers: ASTM E1316-16 - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Feb-2016
• Refers: ASTM E1316-15a - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Dec-2015
• Refers: ASTM E1348-15 - Standard Test Method for Transmittance and Color by Spectrophotometry Using Hemispherical Geometry
• Effective Date: 01-Nov-2015
• Refers: ASTM E1316-15 - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Sep-2015
• Refers: ASTM E1316-14e1 - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Jun-2014
• Refers: ASTM E1316-14 - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Jun-2014
• Refers: ASTM E1316-13d - Standard Terminology for Nondestructive Examinations
• Effective Date: 01-Dec-2013
• Refers: ASTM E1316-13c - Standard Terminology for Nondestructive Examinations
• Effective Date: 15-Jun-2013

Overview

ASTM E3022-18 is the standard practice issued by ASTM International for the measurement of emission characteristics and requirements for LED UV-A lamps used in fluorescent penetrant and magnetic particle testing. These lamps play a crucial role in nondestructive testing (NDT) by providing ultraviolet A (UV-A) radiation to excite fluorescent dyes or pigments, enhancing contrast and the detection of surface discontinuities in materials.

This standard specifies methods for evaluating and certifying the performance of UV-A LED lamps, with detailed test procedures and requirements. It is intended for manufacturers to certify specific lamp models and includes guidance for the acceptance testing of individual lamps delivered to users. Importantly, this document is not applicable to mercury vapor, gas-discharge, arc, or luminescent lamps.

Key Topics

• Emission Characteristics: Defines test procedures for evaluating emission spectra, maximum irradiance, beam uniformity, and excitation irradiance in the 347-382 nm range, critical for optimal fluorescent excitation.
• Lamp Types: Covers line-powered and battery-powered hand-held and overhead LED lamps applicable exclusively to fluorescent penetrant and magnetic particle testing.
• Contamination Control: Emphasizes the need for proper filtering to eliminate unwanted visible light (>400 nm) and hazardous UV-B/UV-C emissions, which can interfere with inspection processes or pose health risks.
• Performance Testing: Outlines requirements for thermal stability, current ripple minimization (pulse width modulation and pulse firing are not permitted), beam irradiance profiles, and filter transmittance.
• Battery Performance: Specifies battery discharge testing for portable lamp models to ensure performance consistency throughout use.
• Safety and Certification: Requires conformance certification be provided with each lamp, including test results and confirmation that safety, health, and regulatory considerations have been addressed.
• Measurement and Calibration: Details equipment and calibration requirements for UV-A radiometers, spectroradiometers, and spectrophotometers used in lamp testing.

Applications

LED UV-A lamps tested to ASTM E3022-18 are essential in:

• Fluorescent Penetrant Inspection (FPI): Used extensively in the aerospace, automotive, and manufacturing industries for the detection of surface-breaking flaws and discontinuities in non-porous materials.
• Fluorescent Magnetic Particle Testing (FMT): Critical for inspecting ferromagnetic components, ensuring detection of cracks or defects.
• Quality Assurance: Standardization ensures lamps deliver reliable, repeatable UV-A emission characteristics needed for high-contrast inspection environments.
• Manufacturing and Maintenance: Enables manufacturers and maintenance providers to verify the suitability and safety of UV-A LED lamps that are integral to NDT operations.
• Compliance and Procurement: Provides a standardized basis for lamp procurement, ensuring products meet industry-recognized minimum performance requirements.

Related Standards

ASTM E3022-18 references and complements several other key standards in the nondestructive testing field:

• ASTM E165/E165M: Liquid Penetrant Examination for General Industry
• ASTM E709: Magnetic Particle Testing
• ASTM E2297: Guide for Use of UV-A and Visible Light Sources in Liquid Penetrant and Magnetic Particle Testing
• ASTM E1417/E1417M, E1208, E1209, E1210, E1219: Practices for various penetrant testing processes
• ASTM E1316: Terminology for Nondestructive Examinations
• ANSI/ISO/IEC 17025 and ANSI/NCSL Z540.3: Requirements for calibration and testing laboratory competence

Keywords: ASTM E3022-18, LED UV-A lamp, fluorescent penetrant testing, magnetic particle inspection, nondestructive testing, emission characteristics, UV-A radiometer, lamp certification, filter transmittance, quality assurance.

Standards Content (Sample)

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.
Designation: E3022 − 18
Standard Practice for
Measurement of Emission Characteristics and
Requirements for LED UV-A Lamps Used in Fluorescent
Penetrant and Magnetic Particle Testing
This standard is issued under the fixed designation E3022; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.1 This practice covers the procedures for testing the
mine the applicability of regulatory limitations prior to use.
performance of ultraviolet A (UV-A), light emitting diode
1.6 This international standard was developed in accor-
(LED) lamps used in fluorescent penetrant and fluorescent
dance with internationally recognized principles on standard-
magnetic particle testing (see Guides E709 and E2297, and
ization established in the Decision on Principles for the
Practices E165/E165M, E1208, E1209, E1210, E1219, E1417/
2 Development of International Standards, Guides and Recom-
E1417M and E1444). This specification also includes report-
mendations issued by the World Trade Organization Technical
ing and performance requirements for UV-A LED lamps.
Barriers to Trade (TBT) Committee.
1.2 These tests are intended to be performed only by the
manufacturer to certify performance of specific lamp models
2. Referenced Documents
(housing, filter, diodes, electronic circuit design, optical
2.1 ASTM Standards:
elements, cooling system, and power supply combination) and
E165/E165M Practice for Liquid Penetrant Testing for Gen-
also includes limited acceptance tests for individual lamps
eral Industry
delivered to the user. This test procedure is not intended to be
E709 Guide for Magnetic Particle Testing
utilized by the end user.
E1208 Practice for Fluorescent Liquid Penetrant Testing
1.3 This practice is only applicable for UV-A LED lamps
Using the Lipophilic Post-Emulsification Process
used in the examination process. This practice is not applicable
E1209 Practice for Fluorescent Liquid Penetrant Testing
to mercury vapor, gas-discharge, arc or luminescent (fluores-
Using the Water-Washable Process
cent) lamps or light guides (for example, borescope light
E1210 Practice for Fluorescent Liquid Penetrant Testing
sources).
Using the Hydrophilic Post-Emulsification Process
E1219 Practice for Fluorescent Liquid Penetrant Testing
1.4 The values stated in inch-pound units are to be regarded
Using the Solvent-Removable Process
as standard. The values given in parentheses are mathematical
E1316 Terminology for Nondestructive Examinations
conversions to SI units that are provided for information only
E1348 Test Method for Transmittance and Color by Spec-
and are not considered standard.
trophotometry Using Hemispherical Geometry
1.5 This standard does not purport to address all of the
E1417/E1417M Practice for Liquid Penetrant Testing
safety concerns, if any, associated with its use. It is the
E1444 Practice for Magnetic Particle Testing for Aerospace
E2297 Guide for Use of UV-A and Visible Light Sources and
This test method is under the jurisdiction of ASTM Committee E07 on
Meters used in the Liquid Penetrant and Magnetic Particle
Nondestructive Testing and is the direct responsibility of Subcommittee E07.03 on
Methods
Liquid Penetrant and Magnetic Particle Methods.
Current edition approved July 1, 2018. Published July 2018. Originally approved 4
2.2 Other Standards:
in 2015. Last previous edition approved in 2015 as E3022-15. DOI: 10.1520/
ANSI/ISO/IEC 17025 General Requirements for the Com-
E3022-18
The use of LED lamps for penetrant examination may be covered by a patent.
petence of Testing and Calibration Laboratories
Interested parties are invited to submit information regarding the identification of
alternative(s) to this patented item to ASTM International Headquarters. Your
comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
NOTE: ASTM International takes no position respecting the validity of any patent contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
rights asserted in connection with any item mentioned in this standard. Users of this Standards volume information, refer to the standard’s Document Summary page on
standard are expressly advised that determination of the validity of any such patent the ASTM website.
rights, and the risk of infringement of such rights, are entirely their own Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
responsibility. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3022 − 18
ANSI/NCSL Z540.3 Requirements for the Calibration of 3.2.9 transmittance, τ—ratio of the radiant flux transmitted
Measuring and Test Equipment through a body to that incident upon it.
4. Significance and Use
3. Terminology
4.1 UV-A lamps are used in fluorescent penetrant and
3.1 Definitions—General terms pertaining to ultraviolet A
magnetic particle examination processes to excite fluorophores
(UV-A) radiation and visible light used in liquid penetrant and
(dyes or pigments) to maximize the contrast and detection of
magnetic examination are defined in Terminology E1316 and
discontinuities. The fluorescent dyes/pigments absorb energy
shall apply to the terms used in this practice.
from the UV-A radiation and re-emit visible light when
3.2 Definitions of Terms Specific to This Standard:
reverting to its ground state. This excitation energy conversion
3.2.1 battery-powered hand-held lamp, n—lamp powered
allows fluorescence to be observed by the human eye.
by a battery used in either stationary or portable applications
4.2 The emitted spectra of UV-A lamps can greatly affect
where line power is not available or convenient.
the efficiency of dye/pigment fluorescent excitation.
3.2.1.1 Discussion—These lamps may also have the option
4.3 Some high-intensity UV-A lamps can produce irradiance
to be line-powered (that is, alternating current power supply).
greater than 10 000 μW/cm at 15 in. (381 mm). All high-
Smaller lamps, often referred to as “flashlights” or “torches”
intensity UV-A light sources can cause fluorescent dye fade
are used for portable examination of focused zones and often
and increase exposure of the inspector’s unprotected eyes and
have a single LED.
skin to high levels of damaging radiation.
3.2.2 current ripple, n—unwanted residual periodic varia-
4.4 UV-A lamps can emit unwanted visible light and harm-
tion (spikes or surges) of the constant current that drives the
ful UV radiation if not properly filtered. Visible light contami-
LED at a constant power level.
nation above 400 nm can interfere with the inspection process
3.2.2.1 Discussion—Ripple is due to incomplete suppres-
and must be controlled to minimize reflected glare and maxi-
sion of DC (peak to peak) variance resulting from the power
mize the contrast of the indication. UV-B and UV-C contami-
supply, stability of regulation circuitry, circuit design, and
nation must also be eliminated to prevent exposure to harmful
quality of the electronic components.
radiation.
3.2.3 excitation irradiance, n—irradiance calculated in the
4.5 Pulse Width Modulation (PWM) and Pulse Firing (PF)
range of 347 nm and 382 nm. This corresponds to the range of
of UV-A LED circuits are not permitted.
wavelengths that effectively excite fluorescent penetrant dyes
(i.e. greater than 80% of relative peak excitation).
NOTE 1—The ability of existing UV-A radiometers and spectroradiom-
eters to accurately measure the irradiance of pulse width modulated or
3.2.4 irradiance, E, n—radiant flux (power) per unit area
pulsed fired LEDs and the effect of pulsed firing on indication detectability
incident on a given surface. Typically measured in units of
is not well understood.
micro-watts per square centimeter (μW/cm ).
5. Classifications
3.2.5 lamp model, n—A lamp with specific design. Any
5.1 LED UV-A lamps used for nondestructive testing shall
change to the lamp design requires a change in model
be of the following types:
designation and complete qualification of the new model.
5.1.1 Type A—Line-powered lamps (LED arrays for hand-
3.2.6 light-emitting diode, LED, n—solid state electronic
held and overhead applications) (3.2.5 and 3.2.6).
devices consisting of a semiconductor or semiconductor ele-
5.1.2 Type B—Battery powered hand-held lamps (LED ar-
ments that emit radiation or light when powered by a current.
rays for stationary and portable applications) (3.2.1).
3.2.6.1 Discussion—LEDs emit a relatively narrow band-
5.1.3 Type C—Battery powered, handheld lamps (single
width spectrum when a specific current flows through the chip.
LED flashlight or torch for special applications) (3.2.1, Dis-
The emitted wavelengths are determined by the semiconductor
cussion).
material and the doping. The intensity and wavelength can
change depending on the current, age, and chip temperature.
6. Apparatus
3.2.7 line-powered lamp, n—corded hand-held or overhead
6.1 UV-A Radiometer, designed for measuring the irradiance
lamps that are line-powered and typically used for stationary
of electromagnetic radiation. UV-A radiometers use a filter and
inspections within a controlled production environment.
sensor system to produce a bell-shaped (i.e. Gaussian) response
3.2.7.1 Discussion—These lamps are used for examination
at 365 nm (3650 Å) or top-hat responsivity centered near
of both small and large inspection zones and consist of an LED
365 nm (3650 Å). 365 nm (3650 Å) is the peak wavelength
array. Overhead lamps are used in a stationary inspection booth
where most penetrant fluorescent dyes exhibit the greatest
to flood the inspection area with UV-A radiation. Handheld
fluorescence. Ultraviolet radiometers shall be calibrated in
lamps are used to flood smaller regions with UV-A radiation
accordance with ANSI/ISO/IEC 17025, ANSI/NCSL Z540.3,
and can also be used in portable applications where line power
or equivalent. Radiometers shall be digital and provide a
is available.
resolution of at least 5 μW/cm . The sensor front end aperture
width or diameter shall not be greater than 0.5 in. (12.7 mm).
3.2.8 minimum working distance, n—the distance from the
inspection surface where the lamp beam profile begins to
NOTE 2— Photometers or visible light meters are not considered
exhibit non-uniformity. adequate for measuring the visible emission of UV-A lamps which
E3022 − 18
TABLE 1 UV-A LED Lamp Test Requirements by Lamp Model
filter of the lamp is 15.0 6 0.25 in. (381 6 12.7 mm) from the
Type Test Requirements radiometer sensor. Scan the radiometer across the projected
7.3 Maximum Irradiance beam in two orthogonal directions to locate the point of
7.4 Beam Irradiance Profile
maximum irradiance. Record the maximum irradiance value.
7.5 Minimum Working Distance
7.6 Temperature Stability
7.4 Beam Irradiance Profile—Affix the UV-A lamp above
7.6.1 Maximum Housing Temperature
the surface of a flat, workbench with the projected beam
7.6.4 Emission Spectrum
A
orthogonal to the workbench surface.
7.6.4.7 Peak Wavelength
7.6.4.8 Full Width Half Maximum (FWHM)
7.4.1 Type A lamps shall be supplied with alternating
7.6.4.8 Longest Wavelength at Half Maximum
current (ac) power supply at the manufacturer’s rated power
7.6.4.9 Excitation Irradiance
requirement. Power conditioning shall be used to ensure a
7.6.5 Current Ripple
7.8 Filter Transmittance
stable power supply free of voltage spikes, ripples, or surges
from the power supply network.
7.3 Maximum Irradiance
7.4.2 Type B and C lamps shall be powered using a constant
7.4 Beam Irradiance Profile
7.5 Minimum Working Distance
voltage power direct current (DC) supply that provides con-
7.6 Temperature Stability
stant DC power at the rated, fully charged battery voltage
7.6.1 Maximum Housing Temperature
60.5 V.
7.6.4 Emission Spectrum
B, C
7.6.4.8 Full Width Half Maximum (FWHM)
7.4.3 The UV-A lamp shall be turned on and allowed to
7.6.4.8 Longest Wavelength at Half Maximum
stabilize for a minimum of 30 min before taking measure-
7.6.4.9 Excitation Irradiance
ments.
7.6.5 Current Ripple
7.7 Typical Battery Discharge Time and Discharge Plot
7.4.4 Place the UV-A radiometer on the workbench. Adjust
7.8 Filter Transmittance
the lamp position such that the face of the lamp is 15.0 6
0.25 in. (381 6 6 mm) from the radiometer sensor. Scan the
radiometer across the projected beam in two orthogonal
generally have wavelengths in the 400 nm to 450 nm range.
directions to locate the point of maximum irradiance. Record
6.2 Spectroradiometer, designed to measure the spectral
this location as the zero point. Using a 0.5-in. (12.7-mm) grid,
irradiance and absolute irradiance of electromagnetic emission
translate the radiometer across the projected beam in 0.5-in.
sources. Measurement of spectral irradiance requires that such
(12.7-mm) increments to generate a two-dimensional (2-D)
instruments be coupled to an integrating sphere or cosine
plot of the beam profile (irradiance versus position). Position
corrector. This spectroradiometer shall have a resolution of at
the radiometer using either an x-y scanner or by manually
least 0.5 nm and a minimum signal-to-noise ratio of 50:1. The
scanning. When manually scanning, use a sheet with 0.5-in.
system shall be capable of measuring absolute spectral irradi-
(1.27-cm) or finer squares and record the irradiance value in
ance over a minimum range of 300 to 400 nm.
the center of each square. The beam irradiance profile shall
6.2.1 The system shall be calibrated using emission source
extend to the point at which the irradiance drops below
reference standards.
200 μW ⁄cm2.
7.4.5 Generate and report the 2-D plot of the beam irradi-
6.3 Spectrophotometer, designed to measure transmittance
ance profile (see
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E3022 − 15 E3022 − 18
Standard Practice for
Measurement of Emission Characteristics and
Requirements for LED UV-A Lamps Used in Fluorescent
Penetrant and Magnetic Particle Testing
This standard is issued under the fixed designation E3022; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice covers the procedures for testing the performance of ultraviolet A (UV-A), light emitting diode (LED) lamps
used in fluorescent penetrant and fluorescent magnetic particle testing (see Guides E709 and E2297, and Practices E165/E165M,
E1208, E1209, E1210, E1219, E1417/E1417M and E1444). This specification also includes reporting and performance
requirements for UV-A LED lamps.
1.2 These tests are intended to be performed only by the manufacturer to certify performance of specific lamp models (housing,
filter, diodes, electronic circuit design, optical elements, cooling system, and power supply combination) and also includes limited
acceptance tests for individual lamps delivered to the user. This test procedure is not intended to be utilized by the end user.
1.3 This practice is only applicable for UV-A LED lamps used in the examination process. This practice is not applicable to
mercury vapor, gas-discharge, arc or luminescent (fluorescent) lamps or light guides (for example, borescope light sources).
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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2.1 ASTM Standards:
E165/E165M Practice for Liquid Penetrant Examination for General Industry
E709 Guide for Magnetic Particle Testing
E1208 Practice for Fluorescent Liquid Penetrant Testing Using the Lipophilic Post-Emulsification Process
E1209 Practice for Fluorescent Liquid Penetrant Testing Using the Water-Washable Process
E1210 Practice for Fluorescent Liquid Penetrant Testing Using the Hydrophilic Post-Emulsification Process
E1219 Practice for Fluorescent Liquid Penetrant Testing Using the Solvent-Removable Process
E1316 Terminology for Nondestructive Examinations
E1348 Test Method for Transmittance and Color by Spectrophotometry Using Hemispherical Geometry
E1417/E1417M Practice for Liquid Penetrant Testing
This test method is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.03 on Liquid
Penetrant and Magnetic Particle Methods.
Current edition approved Sept. 1, 2015July 1, 2018. Published September 2015July 2018. Originally approved in 2015. Last previous edition approved in 2015 as
E3022-15. DOI: 10.1520/E3022-1510.1520/E3022-18
The use of LED lamps for penetrant examination may be covered by a patent. Interested parties are invited to submit information regarding the identification of
alternative(s) to this patented item to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee,
which you may attend.
NOTE: ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard
are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. 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
E3022 − 18
E1444 Practice for Magnetic Particle Testing
E2297 Guide for Use of UV-A and Visible Light Sources and Meters used in the Liquid Penetrant and Magnetic Particle Methods
2.2 Other Standards:
ANSI/ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories
ANSI/NCSL Z540.3 Requirements for the Calibration of Measuring and Test Equipment
3. Terminology
3.1 Definitions—General terms pertaining to ultraviolet A (UV-A) radiation and visible light used in liquid penetrant and
magnetic examination are defined in Terminology E1316 and shall apply to the terms used in this practice.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 battery-powered hand-held lamp, n—lamp powered by a battery used in either stationary or portable applications where
line power is not available or convenient.
3.2.1.1 Discussion—
These lamps may also have the option to be line-powered (that is, alternating current power supply). Smaller lamps, often referred
to as “flashlights” or “torches” are used for portable examination of focused zones and often have a single LED.
3.2.2 current ripple, n—unwanted residual periodic variation (spikes or surges) of the constant current that drives the LED at
a constant power level.
3.2.2.1 Discussion—
Ripple is due to incomplete suppression of DC (peak to peak) variance resulting from the power supply, stability of regulation
circuitry, circuit design, and quality of the electronic components.
3.2.3 excitation irradiance, n—irradiance calculated in the range of 347 nm and 382 nm. This corresponds to the range of
wavelengths that effectively excite fluorescent penetrant dyes (i.e. greater than 80% of relative peak excitation).
3.2.4 irradiance, E, n—radiant flux (power) per unit area incident on a given surface. Typically measured in units of micro-watts
per square centimeter (μW/cm ).
3.2.5 lamp model, n—A lamp with specific design. Any change to the lamp design requires a change in model designation and
complete qualification of the new model.
3.2.6 light-emitting diode, LED, n—solid state electronic devices consisting of a semiconductor or semiconductor elements that
emit radiation or light when powered by a current.
3.2.6.1 Discussion—
LEDs emit a relatively narrow bandwidth spectrum when a specific current flows through the chip. The emitted wavelengths are
determined by the semiconductor material and the doping. The intensity and wavelength can change depending on the current, age,
and chip temperature.
3.2.7 line-powered lamp, n—corded hand-held or overhead lamps that are line-powered and typically used for stationary
inspections within a controlled production environment.
3.2.7.1 Discussion—
These lamps are used for examination of both small and large inspection zones and consist of an LED array. Overhead lamps are
used in a stationary inspection booth to flood the inspection area with UV-A radiation. Handheld lamps are used to flood smaller
regions with UV-A radiation and can also be used in portable applications where line power is available.
3.2.8 minimum working distance, n—the distance from the inspection surface where the lamp beam profile begins to exhibit
non-uniformity.
3.2.9 transmittance, τ—ratio of the radiant flux transmitted through a body to that incident upon it.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
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4. Significance and Use
4.1 UV-A lamps are used in fluorescent penetrant and magnetic particle examination processes to excite fluorophores (dyes or
pigments) to maximize the contrast and detection of discontinuities. The fluorescent dyes/pigments absorb energy from the UV-A
radiation and re-emit visible light when reverting to its ground state. This excitation energy conversion allows fluorescence to be
observed by the human eye.
4.2 The emitted spectra of UV-A lamps can greatly affect the efficiency of dye/pigment fluorescent excitation.
4.3 Some high-intensity UV-A lamps can produce irradiance greater than 10 000 μW/cm at 15 in. (381 mm). All high-intensity
UV-A light sources can cause fluorescent dye fade and increase exposure of the inspector’s unprotected eyes and skin to high levels
of damaging radiation.
4.4 UV-A lamps can emit unwanted visible light and harmful UV radiation if not properly filtered. Visible light contamination
above 400 nm can interfere with the inspection process and must be controlled to minimize reflected glare and maximize the
contrast of the indication. UV-B and UV-C contamination must also be eliminated to prevent exposure to harmful radiation.
4.5 Pulse Width Modulation (PWM) and Pulse Firing (PF) of UV-A LED circuits are not permitted.
NOTE 1—The ability of existing UV-A radiometers and spectroradiometers to accurately measure the irradiance of pulse width modulated or pulsed
fired LEDs and the effect of pulsed firing on indication detectability is not well understood.
5. Classifications
5.1 LED UV-A lamps used for nondestructive testing shall be of the following types:
5.1.1 Type A—Line-powered lamps (LED arrays for handheld and overhead applications) (3.2.5 and 3.2.6).
5.1.2 Type B—Battery powered hand-held lamps (LED arrays for stationary and portable applications) (3.2.1).
5.1.3 Type C—Battery powered, handheld lamps (single LED flashlight or torch for special applications) (3.2.1, Discussion).
6. Apparatus
6.1 UV-A Radiometer, designed for measuring the irradiance of electromagnetic radiation. UV-A radiometers use a filter and
sensor system to produce a bell-shaped (i.e. Gaussian) response at 365 nm (3650 Å) or top-hat responsivity centered near 365 nm
(3650 Å). 365 nm (3650 Å) is the peak wavelength where most penetrant fluorescent dyes exhibit the greatest fluorescence.
Ultraviolet radiometers shall be calibrated in accordance with ANSI/ISO/IEC 17025, ANSI/NCSL Z540.3, or equivalent.
Radiometers shall be digital and provide a resolution of at least 5 μW/cm . The sensor front end aperture width or diameter shall
not be greater than 0.5 in. (12.7 mm).
NOTE 2— Photometers or visible light meters are not considered adequate for measuring the visible emission of UV-A lamps which generally have
wavelengths in the 400 nm to 450 nm range.
6.2 Spectroradiometer, designed to measure the spectral irradiance and absolute irradiance of electromagnetic emission sources.
Measurement of spectral irradiance requires that such instruments be coupled to an integrating sphere or cosine corrector. This
spectroradiometer shall have a resolution of at least 0.5 nm and a minimum signal-to-noise ratio of 50:1. The system shall be
capable of measuring absolute spectral irradiance over a minimum range of 300 to 400 nm.
6.2.1 The system shall be calibrated using emission source reference standards.
6.3 Spectrophotometer, designed to measure transmittance or color coordinates of transmitting specimens. The system shall be
able to perform a measurement of regular spectral transmittance over a minimum range of 300 to 800 nm.
7. Test Requirements
7.1 Lamp models used for nondestructive testing (NDT) shall be tested in accordance with the requirements of Table 1.
7.2 LEDs of UV-A Lamps shall be continuously powered with the LED drive current exhibiting minimum ripple (see 7.6.5).
The projected beam shall also not exhibit any perceivable variability in projected beam intensity (i.e. strobing, flicker, etc.) (see
7.4.6).
7.3 Maximum Irradiance—Fixture the UV-A lamp 15 6 0.25 in (381 6 6 mm) above the surface of a flat, level workbench with
the projected beam orthogonal to the workbench surface. The lamp face shall be parallel to the bench within 60.25 in. (66 mm).
Ensure that battery-powered lamps (Types B and C) are fully charged. Turn on the lamp and allow to stabilize for 5 min. Place
a UV-A radiometer, conforming to 6.1, on the workbench. Adjust the lamp position such that the filter of the lamp is 15.0 6 0.25
in. (381 6 12.7 mm) from the radiometer sensor. Scan the radiometer across the projected beam in two orthogonal directions to
locate the point of maximum irradiance. Record the maximum irradiance value.
7.4 Beam Irradiance Profile—Affix the UV-A lamp above the surface of a flat, workbench with the projected beam orthogonal
to the workbench surface.
7.4.1 Type A lamps shall be supplied with alternating current (ac) power supply at the manufacturer’s rated power requirement.
Power conditioning shall be used to ensure a stable power supply free of voltage spikes, ripples, or surges from the power supply
network.
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TABLE 1 UV-A LED Lamp Test Requirements by Lamp Model
Type Test Requirements
7.3 Maximum Irradiance
7.4 Beam Irradiance Profile
7.5 Minimum Working Distance
7.6 Temperature Stability
7.6.1 Maximum Housing Temperature
7.6.4 Emission Spectrum
A
7.6.4.7 Peak Wavelength
7.6.4.8 Full Width Half Maximum (FWHM)
7.6.4.8 Longest Wavelength at Half Maximum
7.6.4.9 Excitation Irradiance
7.6.5 Current Ripple
7.8 Filter Transmittance
7.3 Maximum Irradiance
7.4 Beam Irradiance Profile
7.5 Minimum Working Distance
7.6 Temperature Stability
7.6.1 Maximum Housing Temperature
7.6.4 Emission Spectrum
B, C
7.6.4.8 Full Width Half Maximum (FWHM)
7.6.4.8 Longest Wavelength at Half Maximum
7.6.4.9 Excitation Irradiance
7.6.5 Current Ripple
7.7 Typical Battery Discharge Time and Discharge Plot
7.8 Filter Transmittance
7.4.2 Type B and C lamps shall be powered using a constant voltage power direct current (DC)
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