ASTM International Standard Practice for Evaluation of Instrumental Color Difference with a Gray Scale ASTM E3040-16

1.1 Test Method D2616 describes a painted gray scale and the procedure to be used in the visual evaluation of color differences on non-self-luminous materials by comparison to this scale. This practice provides an alternative method of obtaining a similarly valued result by an instrumental method. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard, except that the test results of this test method are converted by the calculations to an arbitrary visual scale defined by Test Method D2616, whose units are called GSC (Gray Scale for Change in Color). 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.