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 36 of 460

FED-STD-791D

elements to maintain the test temperature. There shall be one thermocouple provided for each

heating element. Figures 1, 2, and 3 show a satisfactory heating block.

4.4 Temperature controller. A suitable temperature controller capable of maintaining

temperatures between 99� to 538�C " 0.5�C. A suitable temperature recorder shall also be

provided.

4.5 Flowmeter. A rotameter calibrated to deliver air at a rate of 2.58 " 0.02 g/min

between 15.6� to 29.4�C (60� and 85�F) (2 L/min at standard temperature and pressure). It shall

be furnished with a needle valve and may be mounted as shown in Figure 7.

4.6 Evaporation tester stand. A suitable stand for supporting the test apparatus is shown

in Figure 5.

5. MATERIALS

5.1 CAUTION - SOME MATERIALS ARE TOXIC AND HAZARDOUS. The

materials references and standards listed in this section must be handled carefully. Federal Test

Method 10000, Material Handling Safety Precautions, is a reference which lists all toxic and

hazardous materials cited in FTMS 791. The synonyms, life hazard, flammability, handling and

storage precautions, emergency treatment and measures, and spill practices of each chemical are

explained.

5.2 1,1,1-Trichloroethane (ASTM D 4126), [2,1,0].

5.3 Tissue, Facial.

6. PROCEDURE

6.1 Greases

6.1.1 Clean the grease-sample cup and hood thoroughly, using warm

1,1,1-trichloroethane (38�-54�C [100�-130�F]) and facial tissues. Dry thoroughly in warm air.

Caution. 1,1,1-trichloroethane is toxic. Use it only in a well ventilated area.

NOTE 1:

Avoid contact with skin.

6.1.2 Weigh the clean grease-sample cup and hood to the nearest mg. Remove the hood

and fill the cup with sample, taking care to avoid occlusion of air. Smooth the surface level with

the rim of the cup with a straight edged spatula. Remove with a clean cloth any grease which

may remain on the rim or threads of the cup. Thread the hood tightly onto the cup without

disturbing the smoothed grease surface. Weigh the assembly and record the net weight of the

sample to the nearest mg.

6.1.3 With cover in place, but without the hood and sample cup attached, allow the

evaporation cell to acquire the temperature of the block (controlled to 2�C ["1�F]), at which the