FED-STD-791 Lubricants, Liquid Fuels, And Related Products, Testing Method OfThis test method standard is composed of standard test methods for sampling, inspecting and testing lubricants, liquid fuels and related products. It is issued pursuant to the Federal Property and Administration Services Act of 1949, as amended and its application to the purchase of commodities referred to herein is mandatory on all Federal agencies.

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'�NOTE:This draft dated 15 April 2006' by DasH - Page 260 of 460

FED-STD-791D

raise the temperature to 760� C and maintain at this temperature until there is no

longer any carbon present. This will require approximately l h at 760�C. The

barium sulfate should be pure white.

p. Allow the crucibles to cool and determine the weight of barium sulfate in each

one. Subtract the weight of barium sulfate in the blank from that of the sample

and record the difference as the weight of barium sulfate. (See note 2).

q. Calculate the percent MoS2 in the grease solids (see 7.2).

r.Calculate the percent MoS2 in the grease (see 7.3).

NOTE 2:

A spectrochemical analysis may be conducted to determine purity of

MoS2.

7. CALCULATIONS

7.1 Calculate the percent solids as follows:

Percent solids = w2 * 100

where:

Wl = weight of solids in sample

W2 = weight of sample

7.2 Calculate the percent MoS2 in the grease solids as follows:

0.343 * M 2

* 100

Percent MoS 2 in grease solids =

where:

M = weight of solids from grease sample

M2 = weight of barium sulfate

7.3 Calculate the percent MoS2 in the grease as follows:

Percent MoS 2 = percent solid (see 7.1)* percent MoS 2 in grease solids (see 7.2)

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