ASTM E2297-23

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: E2297 − 15 E2297 − 23
Standard Guide for
Use of UV-A and Visible Light Sources and Meters used in
the Liquid Penetrant and Magnetic Particle Methods
This standard is issued under the fixed designation E2297; 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 guide describesaddresses the use of UV-A/Visible light sources and meters used for the examination of materials by the
liquid penetrant and magnetic particle processes. This guide may be used to help support the needs for appropriate light intensities
and light measurement.establish practices and procedures to measure irradiance and illuminance levels.
1.2 This guide also provides acts as a reference:
1.2.1 To assist in the selection of light irradiance and illumination sources and meters that meet the applicable specifications or
standards.
1.2.2 For use in the preparation of internal documentation dealing with liquid penetrant or magnetic particle examination of
materials and parts.
1.3 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 standardstandard.
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 healthsafety, 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.
2. Referenced Documents
2.1 ASTM Standards:
E165 Practice for Liquid Penetrant Testing 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
This guide 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 July 15, 2015Jan. 15, 2023. Published September 2015March 2023. Originally approved 2004. Last previous edition approved in 20102015 as
E22973–04(2010).E2297 – 15. DOI: 10.1520/E2297-15.10.1520/E2297-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 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.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2297 − 23
E1219 Practice for Fluorescent Liquid Penetrant Testing Using the Solvent-Removable Process
E1220 Practice for Visible Penetrant Testing Using Solvent-Removable Process
E1316 Terminology for Nondestructive Examinations
E1417E1417/E1417M Practice for Liquid Penetrant Testing
E1418 Practice for Visible Penetrant Testing Using the Water-Washable Process
E1444E1444/E1444M Practice for Magnetic Particle Testing for Aerospace
E3022 Practice Forfor Measurement of Emission Characteristics and Requirements for LED UV-A Lamps Used in Fluorescent
Penetrant and Magnetic Particle Testing
E3024 Practice for Magnetic Particle Testing for General Industry
2.2 ANSI Standard:
ANSI/NCSL Z540.3 Requirements for the Calibration of Measuring and Test Equipment
2.3 ICNIRP Document:
International Commission on Nonionizing Radiation Protection Statement (ICNIRP Publication-2010) on Protection of Workers
Against Ultraviolet Radiation
2.4 ISO/IEC Standards:
IEC 62471 Photobiological Safety of Lamps and Lamp Systems
ISO/CIE 17166:2019(E) Erythema Reference Action Spectrum and Standard Erythema Dose
ISO 3059 Non-Destructive Testing – Penetrant Testing and Magnetic Particle Testing – Viewing Conditions
ISO 10012 Measurement Management Systems – Requirements for Measurement Processes and Measuring Equipment
ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories
2.5 ASNT Documents:
ASNT Handbook, Volume 1, Liquid Penetrant Testing
ASNT Handbook, Volume 8, Magnetic Particle Testing
3. Terminology
3.1 The definitions that appear in Terminology E1316, relating to UV-A radiation and visible light used in liquid penetrant and
magnetic particle examinations, shall apply to the terms used in this guide. The terms source and lamp are used interchangeably
in this guide.
3.2 Definitions:
3.2.1 high-intensity UV-A source—source, n—a light source UV-A source or lamp that produces UV-A irradiance greater than
2 2
10 000 μW ⁄cm (100 W ⁄m ) at 38.1 cm (15 in.).
3.2.2 illuminance—illuminance, n—the amount of visible light, weighted by the luminosity function to correlate with human
perception, incident on a surface, per unit area. Typically reported in units of lux (lx), lumens per square metremeter (lm/m )), or
footcandle (fc).
3.2.3 illuminance photometer, n—an instrument incorporating a sensor and optical filters to measure illuminance.
3.2.4 irradiance—irradiance, n—the power of electromagnetic radiation incident on a surface, per unit area. Typically reported
2 2
in units of watts per square metremeter (W/m ) or microwatts per square centimetre (μW/cm ).
3.2.5 radiometer—radiometer, n—in NDT, an instrument incorporating a sensor and optical filters to measure the irradiance of
light over a defined range of wavelengths.
4. Summary of Guide
4.1 This guide describes the properties of UV-A sources and visible light sources used for liquid penetrant and magnetic particle
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from International Commission on Nonionizing Radiation Protection (ICNIRP), https://www.icnirp.org.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland,
https://www.iso.org.
Available from American Society for Nondestructive Testing (ASNT), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
E2297 − 23
examination. This guide also describes the properties of radiometers and light meters used to determine if adequate light levels
(UV-A or visible, or both) are present photometers used to measure UV-A or visible light as applicable, while conducting a liquid
penetrant or magnetic particle examination.
5. Significance and Use
5.1 UV-A and visible light sources are used to provide adequate lightillumination levels for liquid penetrant and magnetic particle
examination. Radiometers and light metersUV-A sources, UV-A radiometers, visible light sources, and illuminance photometers
are used to verify that specified light levels are available.specified viewing conditions.
5.2 Fluorescence is typically produced by irradiating the fluorescent dyes/pigments with UV-A radiation. The fluorescent
dyes/pigments absorb the energy from the UV-A radiation and re-emit light energy in the visible spectrum. This energy transfer
process allows fluorescence to be observed by the human eye.
5.3 UV-A light sources may emit visible light above 400 nm (400 Å), (4000 Å), which may reduce the visiblityvisibility of
fluorescent indications. High intensity UV-A light sources may cause UV fade, causing fluorescent indications to degrade or
disappear.
6. Equipment
6.1 Ultraviolet (UV)/Visible LightIrradiation Spectrum
6.1.1 UV light sources emit radiation in the ultraviolet section of the electromagnetic spectrum, between 180 nm (1800100 nm
(1000 Å) to 400 nm (4000 Å). Ultraviolet radiation is a part of the electromagnetic radiation spectrum between the violet/blue color
of the visible spectrum and the weak X-ray spectrum. (See Fig. 1.)
6.1.2 The UV-A range is considered to be between 320 nm (3200 Å) and 400 nm (4000 Å). This UV-A range is specific to the
liquid penetrant and magnetic particle inspection methods and may not be consistent with other international standards.
6.1.3 The UV-B range (medium UV) is considered to be between 280 nm (2800 Å) and 320 nm (3200 Å).
6.1.4 The UV-C range (short UV) is considered to be between 180 nm (1800100 nm (1000 Å) and 280 nm (2800 Å).
6.1.5 The visible spectrum is considered to be between 400 nm (4000 Å) and 760 nm (7600 Å). This range of visible light is
specific to the liquid penetrant and magnetic particle inspection methods and may not be consistent with other international
standards.
6.2 Mercury Vapor UV-A Sources
6.2.1 Most Mercury vapor UV-A sources utilize a lamp containing a mercury-gas plasma that emits radiation specific to the
mercury atomic transition spectrum. There are several discrete element emission lines of the mercury spectrum in the ultraviolet
FIG. 1 The Electromagnetic Radiation Spectrum
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section of the electromagnetic spectrum. The irradiance output is dependent on the gas pressure and the amount of mercury content.
Higher values of gas pressure and mercury content result in significant increase in its UV emission. Irradiance output is also
dependent on the input voltage and the age of the lamp bulb. As the bulb ages, mercury diffuses into the enclosing glass, causing
the emission to decrease.
6.2.2 Mercury vapor UV-A sources used for NDT must have appropriate filters, either internal or external to the light source, lamp,
to pass UV-A (6.1.2) and minimize visible light (6.1.5) output that is detrimental to the fluorescent inspection process. These UV-A
pass filters should also block harmful UV-B (6.1.3) and UV-C (6.1.4) radiation.
6.2.3 Mercury vapor bulbs used for fluorescent NDT are generally low- or medium-pressure vapor sources.
6.2.3.1 Low-pressure bulbs (luminescent(fluorescent tubes) are coated with a special phosphor in order to maximize the UV-A
output. Typically, low-pressure lamps are used in wash stations or for general UV-A lightingirradiance in the inspection room.
6.2.3.2 Medium-pressure bulbs do not have phosphor coatings but operate at higher electrical power levels, resulting in
significantly higher UV-A output.
6.2.4 Medium-pressure lamps are typically used for fluorescent examination. A well designed medium pressure UV-A lamp with
a suitable UV-A pass filter should emit less than 0.25 % to 1 % of its total intensity outside of the UV-A range. A typical lamp is
based on the American National Standards Institute’s Specification H 44 GS-R100, is a 100 watt mercury-vapor bulb in the Par
38 configuration, and normally uses a Kopp 1041 or Kopp 1071 UV filter. Other lamps using the same bulb but with an alternate
UV-A pass filter with similar transmission characteristics, or bulbs based on the Philips HPW 125-watt bulbcharacteristics will not
differ greatly in UV-A output, but may produce more visible light in the blue/violet part of the spectrum.
NOTE 1—The Philips HPW 125-watt bulb has been restricted from use in the inspection station by many aerospace companies.
6.3 UV-A Borescope, Fiberscope, or Video-image-scope and Special UV-A Light Source Systems
6.3.1 Borescopes, fiberscopes, and video-image-scopes are thin rigid or flexible tubular optical telescopes. They are non
destructive nondestructive inspection quality control instruments for the visual detection of surface discontinuities in small bores,
castings, pipe interiors, and on internal components of complex machinery.
6.3.2 The conventional optical glass fiber used as a light guide in borescopes, fiberscopes, and video image scopes may be a poor
transmitter of UV-A radiation. These fibers transmit whitevisible light in the 450 to 760 nm (4500 to 7600 Å) range, but do not
effectively transmit light in the 350 to 380 nm (3500 to 3800 Å) range.
6.3.3 Three non traditional non-traditional light guide materials for improved UV-A transmission in borescopes, fiberscopes, or
video-image-scopes, are liquid light guides, silica or quartz fibers, or special new glass fibers.
6.3.3.1 Silica or quartz fibers are good transmitters of UV-A energy, but are brittle and cannot be bent into a tight radius without
breaking, nor can they accommodate the punishing stresses of repeated scope articulation.
6.3.3.2 Liquid light guides are very effective transmitters of UV-A, but have minimum diameter limitations at 2.5 mm and also
exhibit problems with collapsing, kinking, or loss of fluids.
6.3.3.3 A special glass fiber configuration offers the best UV performance plus durability. Special glass fiber light bundles combine
high UV output with the necessary flexibility and durability required in these scopes.
6.3.4 Electronic digital borescopes have one end composed of a small LED source and a digital embedded camera. As the guide
only carries electric signals, the length can be several meters.
6.4 UV-A Pencil Lamps
6.4.1 The pencil lamp is one of the smallest sources of UV-A radiation. It is generally a lamp coated with conversion phosphors
that absorb the 254 nm (2540 Å) line of energy and convert this energy into a band peaking at 365 nm (3650 Å). The lamp may
Kopp 1041 UV and Kopp 1071 UV are registered trademarks of Kopp Glass Inc., Pittsburgh, PA.
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be encased in a tubular glass filter that absorbs visible light while transmitting maximum ultraviolet intensity. The pencil lamp is
useful for fluorescent analysis and boroscopic inspection in inaccessible locations.
NOTE 1—Pencil Lampslamps produce low levels of UV-A radiation.
6.4.2 As with all metal vapor discharge lamps, the output of a quartz pencil lamp slowly decreases throughout its life. The actual
useful life will primarily be dependent upon dust and other contaminants collecting on the lamp and its reflecting and transmissive
elements. UV-A intensity loss also occurs as the lamp ages.
6.5 High Intensity UV-A Light Sources
6.5.1 Metal Halide UV-A Sources: Sources—The high intensity flood fixture normally uses a high wattage metal halide bulb. This
lamp will also contain some type of specially coated parabolic bulb with a reflector. The high intensity of this lamp will produce
a great deal of heat, so some type of cooling fan must be used.
6.5.2 Micro-Discharge (MDL) Lamp UV-A Sources: Sources—The MDL lamp uses a 35 watt 35-watt metal halide bulb and
therefore produces very little heat. Normally, a cooling fan is not required. These lamps use a high-pressure arc bulb containing
xenon gas or a mixture of mercury vapor and xenon gas.
6.5.3 Xenon Bulb UV-A Sources: These lamps use a high-pressure arc bulb containing xenon gas or a mixture of mercury vapor
and xenon gas.
6.5.3 High Intensity UV-A sourceslamps have broad emission spectra, which may include more than one peak within the UV-A
range (6.1.2). For use in fluorescent NDT, these lamps must have appropriate filters, either internal or external to the light source,
to pass UV-A (6.1.2) and minimize visible light (6.1.5) output that is detrimental to the fluorescent inspection process. These UV-A
filters should also block harmful UV-B (6.1.3) and UV-C (6.1.4) radiation.
Warning—UV-A light sources may emit visible light above 400 nm (4000 Å), which may reduce the visibility of fluorescent
indications. High intensity UV-A sources may cause UV fade, causing fluorescent indications to disappear.Caution—UV-A
sources may emit visible light above 400 nm (4000 Å), which may reduce the visibility of fluorescent indications. High intensity
UV-A sources may cause UV fade, causing fluorescent
...