ASTM E2152-01

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:E2152–01
Standard Practice for
Computing the Colors of Fluorescent Objects from
Bispectral Photometric Data
This standard is issued under the fixed designation E 2152; 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.
INTRODUCTION
The fundamental procedure for evaluating the color of a fluorescent specimen is to obtain bispectral
photometric data for specified irradiating and viewing geometries, and from these data to compute
tristimulus values based on a CIE (International Commission on Illumination) standard observer and
a CIE standard illuminant. Procedures for such computation are contained in this practice. This
practice also contains procedures for computing illuminant-specific spectral radiance factor values
from illuminant-independent bispectral photometric data.
1. Scope CIE Publication 15.2, Colorimetry
1.1 This practice provides the values and practical compu-
tation procedures needed to obtain tristimulus values, desig-
2.3 ISO Standards:
nated X, Y, Z and X ,Y ,Z for the CIE 1931 and 1964
10 10 10
ISO 11476 Paper and Board—Determination of CIE-
observers, respectively, from bispectral photometric data for
Whiteness, C/2 Degrees
the specimen. Procedures for obtaining such bispectral photo-
metric data are contained in Practice E 2153.
3. Terminology
1.2 Procedures for conversion of results to color spaces that
3.1 Definitions—The definitions contained in Terminology
are part of the CIE system, such as CIELAB and CIELUV are
E 284 are applicable to this practice.
contained in Practice E 308.
3.2 Definitions of Terms Specific to This Standard:
1.3 This standard may involve hazardous materials, opera-
3.2.1 bispectrometer—an optical instrument equipped with
tions, and equipment. This standard does not purport to
a source of irradiation, two monochromators, and a detection
address all of the safety concerns, if any, associated with its
system, such that a specimen can be measured at
use. It is the responsibility of the user of this standard to
independently-controlled irradiation and viewing wavelengths.
establish appropriate safety and health practices and deter-
The bispectrometer is designed to allow for calibration to
mine the applicability of regulatory limitations prior to use.
provide quantitative determination of the bispectral radiation-
2. Referenced Documents transfer properties of the specimen.(5)
2.1 ASTM Standards:
NOTE 1—Typically, a reference detection system monitors the radiation
E 284 Terminology of Appearance
incident on the specimen. This reference detection system serves to
compensate for both temporal and spectral variations in the flux incident
E 308 Practice for Computing the Colors of Objects by
upon the specimen, by normalization of readings from the instrument’s
Using the CIE System
emission detection system.
E 2153 Practice for Obtaining Bispectral Photometric Data
3.2.2 diagonal elements—elements of a bispectral matrix
for Evaluation of Fluorescent Color
2.2 CIE Standards: for which irradiation and viewing wavelengths are equal.
3.2.3 fluorescence—this standard uses the term “fluores-
cence” as a general term, including both true fluorescence
This practice is under the jurisdiction of ASTM Committee E12 on Color and
Appearance and is the direct responsibility of Subcommittee E12.05 on Fluores- Available from the USNC/CIE Publications Office, TLA-Lighting Consultants,
cence. Inc., 7 Pond St., Salem, MA 01970–4819.
Current edition approved June 10, 2001. Published August 2001. Available from American National Standards Institute, 11 W. 42nd St., 13th
Annual Book of ASTM Standards, Vol 06.01. Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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.
E2152–01
-8
(with a luminescent decay time of less than 10 s) and 6.2.1 When object will be viewed indoors, by daylight
phosphorescence with a delay time short enough to be indis- filtered through a glass window, use values for the extended
tinguishable from fluorescence for the purpose of colorimetry. version of Illuminant C defined in ISO 11476.
3.2.4 off-diagonal element—any element of a bispectral 6.2.2 When object will be viewed outdoors, by unfiltered
matrix for which irradiation and viewing wavelengths are not daylight, use values for CIE Illuminant D65, or other daylight
equal. illuminants, as defined by the formulas developed by Judd, and
presented in CIE 15.2.
4. Summary of Practice
6.2.3 When object will be viewed under well-defined spe-
4.1 Procedures—Procedures are given for computing from cial conditions of irradiation which are not similar to any
bispectral photometric measurements the CIE tristimulus val-
standard illuminant, a provisional illuminant may be defined.
ues X, Y, Z for the CIE 1931 standard observer and the CIE Such a provisional illuminant must represent the relative
1964 supplementary standard observer. While recognizing the
spectral irradiance upon the object surface under these special
CIE recommendation of numerical integration at 1nm intervals conditions.
(in Publication 15.2) as the basic definition, this practice is
limited in scope to measurements and calculations using 7. Calculation
spectral intervals greater than or equal to 5 nm.
7.1 Calculation of Colorimetric Quantities—Use the
4.2 Calculations—CIE tristimulus values X, Y, Z or X ,
10 method of calculating tristimulus values at 5 nm intervals over
Y ,Z are calculated by numerical summation of the prod-
10 10 the viewing wavelength range 380 to 780 nm, and irradiation
uctsofweightingfactorsforselectedilluminantsandobservers
wavelength range 300 to 780 nm.
with the bispectral Donaldson radiance factor of the specimen.
7.2 Calculation of Tristimulus Values—The calculation pro-
The tristimulus values so calculated may be converted to
cedures described below involve numerical summation of the
coordinates in a more nearly uniform color space such as
products of the Donaldson radiance factor of the specimen and
CIELAB or CIELUV.
a bispectral factor derived from the tabulated standard illumi-
nant and observer functions.After normalization, the sums are
5. Significance and Use
the CIE tristimulus values X, Y, Z. (3, 4, 5)
5.1 The bispectral or two-monochromator method is the
7.2.1 Application of Illuminant Weights—Select the desired
definitive method for the determination of the general
CIE standard illuminant from Tables given in Practice E 308.
radiation-transfer properties of fluorescent specimens (4).In
Multiply each element D(µ,l) of the specimen’s Donaldson
this method, the measuring instrument is equipped with two
matrix by the tabulated value of the relative spectral power of
separate monochromators. The first, the irradiation monochro-
the illuminant F at the element’s irradiation wavelength (µ).
mator, irradiates the specimen with monochromatic light. The
7.2.2 Calculation of Stimulus Function—Obtain the sum
second, the viewing monochromator, analyzes the radiation
over µ of these products at 5 nm intervals over the wavelength
leaving the specimen. A two-dimensional array of bispectral
range 300 to 780 nm. The sum obtained at each viewing
photometric values is obtained by setting the irradiation
wavelength l is the value of the specimen’s stimulus function
monochromator at a series of fixed wavelengths (µ) in the
(relative spectral radiance) F(l), under the specified conditions
ultraviolet and visible range, and for each µ, using the viewing
of irradiation. From these values, either tristimulus values or
monochromator to record readings for each wavelength (l) in
spectral radiance factor values may be derived.
the visible range. The resulting array, once properly corrected,
is known as the Donaldson matrix, and the value of each
F~l! 5 F~µ!D~µ,l! (1)
(
µ 5 300
element (µ,l) of this array is here described as the Donaldson
radiance factor (D(µ,l)). The Donaldson radiance factor is an 7.2.3 Derivation of Tristimulus Values—Use the color-
matching functions selected in 6.1. Multiply the specimen’s
instrument- and illuminant-independent photometric property
of the specimen, and can be used to calculate its color for any stimulus function at each viewing wavelength (l) by the
corresponding tabulated values of the observer color-matching
desired illuminant and observer. The advantage of this method
functions. Obtain the sum of these spectral products at 5 nm
is that it provides a comprehensive characterization of the
intervals over the wavelength range 380 to 780 nm:
specimen’s radiation-transfer properties, without the inaccura-
cies associated with source simulation and various methods of
–
X 5 k x~l!F~l! (2)
approximation. (
l5 380
6. Procedure
–
Y 5 k y~l!F~l!
(
l5 380
6.1 Selecting Standard Observer—Select standard observer
according to the guidelines of Practice E 308.
–
Z 5 k z l!F l!
~ ~
(
6.2 Selecting Illuminants—Select illuminants that are simi-
l5 380
lar to the light under which the objects will be viewed or for
where:
which their colors will be specified or evaluated. In general,
k = the normalization constant:
follow the recommendations of Practice E 308. For fluorescent
samples, however, special attention must be given to the
k 5 (3)
relative UV content of the selected illuminants and the light
–
F~l!y~l!
(
under which the objects will be viewed. l5 380
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.
E2152–01
7.3 Derivation of Other Colorimetric Quantities—Other 7.6.2 Viewing Wavelength Range Less Than 380-780 nm—
colorimetricvalues,suchaschromaticitycoordinates,CIELAB When data for D(µ,l) are not available for the full viewing
andCIELUVvalues,maybecalculatedfromtristimulusvalues wavelength range, add the illuminant or observer wei
...