FED-STD-791D
b. Soak in glass cleaning solution at a temperature of 71C (160F) for 1 h
(minimum time), if glassware contains oil deposits from a previous test.
c. Wash glassware with laboratory detergent. Rinse thoroughly with tapwater
and then with distilled water.
d. Dry in an oven at 100 to 105C (212 to 221 F) and store in dust free
location.
6.2 Clean suspension device and hooks thoroughly with dry cleaning solvent, wipe with
a clean dry cloth, air dry and store in a dust free location.
6.3 Inspect the sheets of standard stock elastomer for flaws. Sections of an elastomeric
sheet having a flaw will not be used for specimens. Cut four specimens from sheets of standard
elastomer stock, with all sheets being from a single production batch, for each lubricant to be
tested. Cut the specimens using ASTM Die C as described in method ASTM D 412. Punch a
0.159 cm (1/16 in) hole in each end of the cut elastomer specimens using a leather punch. The
hole shall be centered and 0.64 cm (1/4 in) from the end of the specimen. Weigh each test
specimen in air and in water in accordance with method ASTM D 471 (and record weights).
Using a type A Shore Durometer obtain four Durometer readings (two on each large end) in
accordance with method ASTM D 2240. Determine the initial hardness of each specimen by
averaging the four readings.
6.4 Preheat and adjust immersion bath to maintain lubricant sample test temperature of
175 1C (347 1.8F) for F-A elastomers specimens and 150 1C (302 1.8F) for FS
elastomer specimens. A suggested method of controlling these temperatures is to place a similar
test tube containing 140 mL of lubricant in the bath at the same depth as the test lubricant. A
thermocouple is then placed in this tube at a depth equal to the depth of the small section of the
elastomeric specimens when suspended in the test lubricant tubes. The test tube containing the
elastomeric specimens and test lubricant is placed into the bath to a depth which places the level
of the test lubricant 4.1 cm (1-5/8 in) above the top of the heating medium and not from the top
of the insulation of bath covering.
6.5 Immerse the elastomeric specimens in the heated test lubricant by means of a
specimen
157
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business