ASTM F2964-12
(Test Method)Standard Test Method for Determining the Uniformity of the Luminance of an Electroluminescent Lamp or Other Diffuse Lighting Device
Standard Test Method for Determining the Uniformity of the Luminance of an Electroluminescent Lamp or Other Diffuse Lighting Device
SIGNIFICANCE AND USE
4.1 Application of an EL lamp (or other diffuse lighting source) to illuminate a device has a functional purpose and must meet specifications to satisfy the functional requirements of the device.
4.2 Illumination of the device or application can be affected by variations in the quality, efficiency, and design of the lamp and any attendant mounting or shading fixtures.
4.3 This test method addresses only the optical and visual appearance of the lamp and not its electrical function.
4.4 This test method is non-destructive.
4.5 This test method is described for application to the illumination layer in which case the results apply to that layer only. However, it may be desirable and practical to apply the test to a further assembly or to a fully assembled device with built in illumination. In such a case, the results refer specifically to the subassembly or the entire device respectively.
SCOPE
1.1 This test method covers procedures for determining the uniformity of the luminance of an electroluminescent (EL) lamp. While written specifically for the purpose of evaluating EL devices, which are intrinsically very uniform, it can be applied (judiciously) to the measurement of any diffuse, essentially planar, light source. For specific purposes, it can be applied to partially assembled devices into which the illumination is installed (such as a membrane switch) as a diagnostic for the performance of the entire device. In such a case it must be understood that the results pertain only to the partial assembly and will be modified as the further assembly proceeds.
1.2 The method is to take a 2-dimensional set of measurements, sampling the surface of the unit under test with appropriate density. The method is restricted to measuring luminance only, since variations in color will also show as luminance non-uniformity especially in any photoptically calibrated measuring device.
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 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.
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Designation: F2964 − 12
Standard Test Method for
Determining the Uniformity of the Luminance of an
1
Electroluminescent Lamp or Other Diffuse Lighting Device
This standard is issued under the fixed designation F2964; 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 F2771 Test Method for Determining the Luminance Curve
of an Electroluminescent Lamp at Ambient Conditions
1.1 This test method covers procedures for determining the
uniformity of the luminance of an electroluminescent (EL)
3. Terminology
lamp. While written specifically for the purpose of evaluating
EL devices, which are intrinsically very uniform, it can be 3.1 Definitions:
applied (judiciously) to the measurement of any diffuse,
3.1.1 luminance, n—measure of the brightness or luminous
essentially planar, light source. For specific purposes, it can be
intensity of light, usually expressed in units of candelas per
2 2
applied to partially assembled devices into which the illumi-
square metre (cd/m ) or foot lamberts. 1 fL = 3.426 cd/m .
nation is installed (such as a membrane switch) as a diagnostic
3.1.2 luminance curve, n—a graphical representation of the
for the performance of the entire device. In such a case it must
variation of luminance with time (implicitly under unvarying
be understood that the results pertain only to the partial
operating conditions).
assembly and will be modified as the further assembly pro-
3.1.3 electroluminescent lamp (EL lamp), n—essentially a
ceeds.
capacitor structure with phosphor and a dielectric sandwiched
1.2 The method is to take a 2-dimensional set of
between electrodes, one of which is transparent to allow light
measurements, sampling the surface of the unit under test with
to escape. Application of an ac voltage across the electrodes
appropriate density. The method is restricted to measuring
generates a charging field within the phosphor, which causes it
luminance only, since variations in color will also show as
to emit light.
luminance non-uniformity especially in any photoptically cali-
3.1.4 time to half luminance (THL), n—the elapsed operat-
brated measuring device.
ing time over which the luminance of a lamp maintained under
1.3 The values stated in SI units are to be regarded as
constant power will be reduced to half of its initial value.
standard. No other units of measurement are included in this
3.1.5 UUT, n—unit under test.
standard.
1.4 This standard does not purport to address all of the
4. Significance and Use
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 4.1 Application of an EL lamp (or other diffuse lighting
source) to illuminate a device has a functional purpose and
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. must meet specifications to satisfy the functional requirements
of the device.
2. Referenced Documents
4.2 Illumination of the device or application can be affected
2
2.1 ASTM Standards:
by variations in the quality, efficiency, and design of the lamp
F2360 Test Method for Determining Luminance of a Mem-
and any attendant mounting or shading fixtures.
brane Switch Backlit with Diffuse Light Source
4.3 This test method addresses only the optical and visual
appearance of the lamp and not its electrical function.
1 4.4 This test method is non-destructive.
This test method is under the jurisdiction of ASTM Committee F01 on
Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane
4.5 This test method is described for application to the
Switches.
illumination layer in which case the results apply to that layer
Current edition approved July 1, 2012. Published August 2012. DOI: 10.1520/
F2964–12
only. However, it may be desirable and practical to apply the
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
test to a further assembly or to a fully assembled device with
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
built in illumination. In such a case, the results refer specifi-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. cally to the subassembly or the entire device respectively.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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F2964 − 12
5. Interferences
5.1 State of Assembly—Tests on incomplete assemblies give
results appropriate to that state of assembly. Specifically, later
application of
...
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