ASTM D2392 Test Method for Color Of Dyed Aviation Gasolines
6. Procedure
6.1 Clean the optical surfaces of the color comparator. Insert the empty fluid tubes in the comparator and adjust the position of the light source until the intensities of the light from both halves of the comparator split-field are equal.
6.2 Rinse and fill one of the tubes with the reference liquid to be used and insert the plunger. Wipe all excess reference liquid from the outside of the tube and from the top of the plunger, and insert the tube on the left side of the comparator.
6.3 Rinse and fill the other tube with the sample to be tested, and insert the plunger. Wipe all excess sample from the outside of the tube and from the top of the plunger, and insert the tube in the right side of the comparator, so that it is directly below the larger of the two openings when the access door is closed.
6.4 Insert the glass permanent-color standards into the comparator and rotate the standards until the color section can be viewed by transmitted light. Turn on the light source and compare the two fields for hue and intensity with the minimum and maximum color sections of the glass permanent-color standards.
6.5 Determine if the hue is approximately the same as the standard and if the intensity of the color is between, or equivalent to, the minimum and maximum, in which case the color of the sample is acceptable. If the hue is different from the standard or if the intensity lies outside the minimum and maximum color sections, report the test as a fail.
