ASTM Color

[Titanium_Alloy]

Hi guys, I was wondering how color is determined on ASTM scale (considering it's a scale). I know nothing about this kind of test, have no idea what does it mean and how numbers are assigned according to color. Mobil lists colors for their oils like ASTM L5.5, 5.5, 4.5, L6.0, 6.0. Why some numbers have letters and others don't? If you can post a link to a testing procedure or some kind of paper where it's explained that would be great. Or just tell us in your own words. Regards,

 

[Al]

About all I know is that the test is ASTM 1500-D. It uses calibrated slides to determine color variations from clear to darker numbers. ASTM 1500-D Sorry - thats all I could find.

 

[Ferb]

Yeah, it's just a comparison between standardized vials/slides and a sample. Put that in front of a bright light and compare. Perhaps the "L" is just a way of saying "it's a light 6.5". ferb!

 

[labman]

It has been years since I did anything with those color standards. There is always a way to quantify things. The numbers simply relate to the standards as the others said. Don't remember any letters.