Color of Transparent Liquids | Gardner Color Scale
ASTM D 1544
ASTM D 1544
This method covers the measurement of the color of transparent liquids by means of comparison with arbitrarily numbered glass standards.
A glass tube is filled with the material that needs to be tested. If the material is perceptibly cloudy it must first be filtered.
Next, the sample tube is compared with glass standards, to determine which standard most closely matches the specimen in brightness and saturation. Hue differences are not relevant and are ignored.
Samples must be liquid and transparent, 10 ml of sample are required for this test.
This method is most often used for lot release testing and quality control of incoming materials.