ASTM D-972 vs D-5800

[Jim Allen]

ASTM D-972 to D-5800: Are these two tests in any way comparabe? I can't get enough info from the ASTM site to help me. Both measure Evaporation loss. I want to compare an 11.4 % weight loss on the D-5800 (Noack Volitility method) to a 1.7 percent weight loss on the ASTM D-972 test. This is fairly arcane for most of us but I'm comparing two gear oils and... well... I need to know! Thanks!

Jim

 

[bruce381]

different test both mesure volitlity BUT time and temp is different on them I do not know if there is a comparision for them.

Call Bobby at analysts INC in Oakland California he will know.
800-424-0099
bruce

 

[MolaKule]

ASTM D 972-02 defines the evaporation test as a "weighed sample of lubricant in an evaporation cell placed in a bath at the desired test temperature..." Heated air is passed over the sample for 22 hrs and the mass is weighed afterwords to determine mass loss."

The temperature of the bath may be between 100 and 150 C. The air flow is 2.58 g/min. According to the D 972 documentation, "To determine evaporation loss when the temps are above 150 C, one must use ASTM D 2595."

In the ASTM D 5800 test, the sample is placed in an evaporative crucible or flask that is heated to 250 C. Air is drawn through the sample for 60 minutes and at the end of the test, the sample is weighed for evaporation mass loss.

The instrumentation is a Selby-Noack instrument.


BTW, most tests are comparable only within the same test procedure.

You should not try to correlate results between different tests since the variables AND instrumentation are different.