Scope:
This test method covers instrumental measurement of a sample using a three-stimulus colorimeter (also known as a three-stimulus filter colorimeter or chromatic difference meter) to obtain color coordinates and chromatic difference values.

The test method specifies the color coordinates and color difference 45:0 and 0:45 geometry measured by reflected or transmitted light using a hemispherical optical measurement system (such as a integrating sphere) or a bidirectional optical measurement system (such as a ring, circumference or single plane).

Because of the limited absolute accuracy of tri-stimulus colorimeters, this test method stipulates that when color coordinates are required, the instrument is standardized using a standard that has similar spectral (color) and geometric characteristics to the sample. This standard is also called product standard. There is a great need to use product standards with appropriate stability.

Because tricolor colorimeters do not provide any information about the reflectance or transmittance curve of the sample, they cannot be used to obtain any information about isochromis or isochromis.

Since a three-stimulus (filter) colorimeter cannot detect isochromia or isochromia of a sample, this test method specifies that two samples need to have similar spectral (color) and geometric characteristics when chromatic aberration is required. In this case, the reflectance measurement of the instrument can be standardized using the white reflectance standard, or for the transmissivity measurement, the instrument can be standardized when no sample or standard is available at the sample location.

ASTM E 1347-2003 “Determination of Color and Color Difference by three-Stimulus Value (Filter) Colorimetric Method”

This test method is usually applicable to samples of any non-fluorescent, flat, object color at all gloss levels. The user needs to determine whether instruments conforming to this method produce results that can be used to evaluate and characterize backfired samples or samples with optical structure.

This test method is not suitable for use with colorimeters, which are spectrometers that provide colorimetric data but not basic spectral data. Measurements made using a spectrocolorimeter are covered in Practice E1164 and in the Method of color Measurement using Spectrophotometry.