ASTM F2360-08

Standard Test Method for Determining Luminance of a Membrane Switch Backlit with Diffuse Light Source

SIGNIFICANCE AND USE
Illumination of a switch or of certain features of a switch often has a functional purpose and must meet specification to satisfy the functional requirements of the switch.
Illumination of the switch can be affected by variations in the quality and design of the overlay and its application.
This test method addresses only the optical and visual appearance of the switch and not its electrical function.
This test method is non-destructive.
If this test method is applied to the entire switch assembly, the results can be applied to the whole device. However, it may be sufficient and practical to apply the test either to a subassembly only, or to the illumination layer only, in which case the results apply to that layer only and the net effect on the fully assembled device must be calculated, extrapolated, or otherwise inferred.
SCOPE
1.1 This test method covers procedures for determining the luminance of a backlit membrane switch. As written, it applies to a fully assembled switch. For specific purposes, it can be applied to partially assembled switches with the understanding that the results pertain only to the partial assembly and will be modified as the further assembly proceeds.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.

General Information

• Status: Historical
• Publication Date: 30-Jun-2008
• ICS: 31.220.20 - Switches
• Technical Committee: F01 - Electronics
• Drafting Committee: F01.18 - Printed Electronics

Relations

• Replaces: ASTM F2360-04 - Standard Test Method for Determining Luminance of a Membrane Switch Backlit with Diffuse Light Source
• Effective Date: 01-Jul-2008
• Replaced By: ASTM F2360-08(2015)e1 - Standard Test Method for Determining Luminance of a Membrane Switch Backlit with Diffuse Light Source
• Effective Date: 01-Jun-2015
• Referred By: ASTM F2771-10(2016) - Standard Test Method for Determining the Luminance Curve of an Electroluminescent Lamp at Ambient Conditions (Withdrawn 2023)
• Effective Date: 01-Jul-2008
• Referred By: ASTM F2964-12(2020) - Standard Test Method for Determining the Uniformity of the Luminance of an Electroluminescent Lamp or Other Diffuse Lighting Device (Withdrawn 2023)
• Effective Date: 01-Jul-2008

Standards Content (Sample)

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
Designation: F2360 − 08
StandardTest Method for
Determining Luminance of a Membrane Switch Backlit with
1
Diffuse Light Source
This standard is issued under the fixed designation F2360; 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 3. Significance and Use
1.1 This test method covers procedures for determining the 3.1 Illuminationofaswitchorofcertainfeaturesofaswitch
luminance of a backlit membrane switch.As written, it applies often has a functional purpose and must meet specification to
to a fully assembled switch. For specific purposes, it can be satisfy the functional requirements of the switch.
applied to partially assembled switches with the understanding
3.2 Illumination of the switch can be affected by variations
that the results pertain only to the partial assembly and will be
in the quality and design of the overlay and its application.
modified as the further assembly proceeds.
3.3 This test method addresses only the optical and visual
1.2 The values stated in SI units are to be regarded as
appearance of the switch and not its electrical function.
standard. No other units of measurement are included in this
3.4 This test method is non-destructive.
standard.
3.5 If this test method is applied to the entire switch
1.3 This standard does not purport to address all of the
assembly, the results can be applied to the whole device.
safety concerns, if any, associated with its use. It is the
However, it may be sufficient and practical to apply the test
responsibility of the user of this standard to establish appro-
either to a subassembly only, or to the illumination layer only,
priate safety and health practices and determine the applica-
in which case the results apply to that layer only and the net
bility of regulatory limitations prior to use.
effect on the fully assembled device must be calculated,
extrapolated, or otherwise inferred.
2. Terminology
4. Interferences
2.1 Definitions:
2.1.1 graphic overlay—a graphically illustrated layer often
4.1 Tests on incomplete assemblies give results appropriate
attached to the topside (or first surface) of the switch assembly
to that state of assembly. Specifically, later application of a
for protection, cosmetic purposes, or to indicate the location
graphic overlay may alter the results.
and function of the switch keys.
4.2 Failure to fill the sampling aperture of the photometer
2.1.2 illumination layer—a layer in the construction of a
will bias the results in a way which is not necessarily
membrane switch, which may or may not be a physically
predictable.
distinct layer which contains or supports the source of illumi-
4.3 Since every system of illumination changes characteris-
nation for the membrane switch. Examples are a flexible layer
tics as it ages, it must be recognized that the results apply to a
containing light emitting diodes (LEDs), often either the top or
particular interval in the lifetime of the system. Characteriza-
bottom layer of the switch, or a flexible layer of electrolumi-
tion of the aging properties may be addressed in a separate test
nescent (EL) material, often a distinct and separate layer added
method.
at assembly.
4.4 Perpendicularity—Since the angular distribution of
2.1.3 membrane switch—a momentary switching device, in
emitted light can be altered by any material through which it
which at least one contact is on, or made of, a flexible
passes, it is important that the photometer be held perpendicu-
substrate.
lar to the area to be sampled.
2.1.4 UUT—unit under test.
4.5 Temperature—Since the performance of many light
sources can vary with temperature, it is important to allow the
UUT to thermally stabilize, if necessary, and then record the
1
This test method is under the jurisdiction of ASTM Committee F01 on
ambient temperature at which the measurements are made.
Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane
Switches.
4.6 Ambient Light—Stray light sources will be detected by
Current edition approved July 1, 2008. Published August 2008. Originally
the photometer and will affect the UUT luminance measure-
approved in 2004. Last previous edition approved in 2004 as F2360-04. DOI:
10.1520/F2360-08. ment. It is important to measure the ambient light before
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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F2360 − 08
illuminating the UUT. This ambient light reading should be 6.5 Switch on the luminous source in the UUT.
zero or as close to zero as possible.
6.6 Measur
...

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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:F2360–04 Designation:F2360–08
Standard Test Method for
Determining Luminance of a Membrane Switch Backlit with
1
Diffuse Light Source
This standard is issued under the fixed designation F 2360; 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 test method covers procedures for determining the luminance of a backlit membrane switch. As written, it applies to
a fully assembled switch. For specific purposes, it can be applied to partially assembled switches with the understanding that the
results pertain only to the partial assembly and will be modified as the further assembly proceeds.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.
2. Terminology
2.1 Definitions:
2.1.1 graphic overlay—a graphically illustrated layer often attached to the topside (or first surface) of the switch assembly for
protection, cosmetic purposes, or to indicate the location and function of the switch keys.
2.1.2 illumination layer—a layer in the construction of a membrane switch, which may or may not be a physically distinct layer
which contains or supports the source of illumination for the membrane switch. Examples are a flexible layer containing light
emitting diodes (LEDs), often either the top or bottom layer of the switch, or a flexible layer of electroluminescent (EL) material,
often a distinct and separate layer added at assembly.
2.1.3 membrane switch—a momentary switching device, in which at least one contact is on, or made of, a flexible substrate.
2.1.4 UUT—unit under test.
3. Significance and Use
3.1 Illumination of a switch or of certain features of a switch often has a functional purpose and must meet specification to
satisfy the functional requirements of the switch.
3.2 Illumination of the switch can be affected by variations in the quality and design of the overlay and its application.
3.3 This test method addresses only the optical and visual appearance of the switch and not its electrical function.
3.4 This test method is non-destructive.
3.5 If this test method is applied to the entire switch assembly, the results can be applied to the whole device. However, it may
be sufficient and practical to apply the test either to a subassembly only, or to the illumination layer only, in which case the results
apply to that layer only and the net effect on the fully assembled device must be calculated, extrapolated, or otherwise inferred.
4. Interferences
4.1 Tests on incomplete assemblies give results appropriate to that state of assembly. Specifically, later application of a graphic
overlay may alter the results.
4.2 Failure to fill the sampling aperture of the photometer will bias the results in a way which is not necessarily predictable.
4.3 Since every system of illumination changes characteristics as it ages, it must be recognized that the results apply to a
particularintervalinthelifetimeofthesystem.Characterizationoftheagingpropertiesmaybeaddressedinaseparatetestmethod.
4.4 Perpendicularity—Since the angular distribution of emitted light can be altered by any material through which it passes,
it is important that the photometer be held perpendicular to the area to be sampled.
4.5 Temperature—Since the performance of many light sources can vary with temperature, it is important to allow the UUT to
thermally stabilize, if necessary, and then record the ambient temperature at which the measurements are made.
4.6 Ambient Light—Stray light sources will be detected by the photometer and will affect the UUT luminance measurement.
1
This test method is under the jurisdiction of ASTM Committee F01 on Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane Switches .
Current edition approved May 1, 2004. Published June 2004.
Current edition approved July 1, 2008. Published August 2008. Originally approved in 2004. Last previous edition approved in 2004 as F 2360-04.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
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