MIL-PRF-85336B
method shall be followed in regard to the apparatus, the preparation of the apparatus, and its
calibration. The procedure used is that described in the test method for the determination of the
surface tension of water. The portion of the procedure dealing with oil-water interfacial tension
does not apply here.
4.5.4 Apparent viscosity. The apparent viscosity at 25 ± 0.5 °C and 55 ± 1 °C shall be
measured with the sample as received. A Brookfield model LVT or LVF viscometer, or
equivalent, shall be used with a #4 spindle (3.2 mm diameter x 31 mm long) immersed in the
lubricant in a container at least 30 mm in diameter. The lubricant sample shall be stirred to ensure
uniformity. At 25 °C the spindle shall be rotated at 60 rpm until a constant reading is obtained,
and then at 12 rpm for 30 seconds. The scale reading taken after 30 seconds is multiplied by 0.5
to give the apparent viscosity. When measuring the apparent viscosity at 55 °C the sample shall
be held at that temperature undisturbed with the spindle immersed for one hour before
measurement. The spindle shall then be rotated at 60 rpm for two minutes, and then at six rpm
for one minute. The scale reading taken after one minute is the apparent viscosity.
4.5.5 Rust prevention. Steel panels fabricated from plain carbon steel, 51 x 102 x 3.2 mm,
with a ground surface, shall be prepared as follows:
a.
Remove obvious contamination, preservatives, and other foreign material,
b.
Wash with hot water and detergent,
c.
Rinse thoroughly with hot water,
d.
Rinse with acetone,
e.
Abrade with clean 320-grit abrasive cloth or paper (do not use wet-or-dry paper),
f.
Rinse with hot tap water followed by distilled water, and
g.
Allow to drain and dry.
The lubricant shall immediately be applied with a glass rod 6 to 8 mm in diameter, by rubbing
across the surface several times, and the excess struck off by passing the rod down the length of
the panel. The rod shall be spaced 0.13 mm above the surface at each side to leave an even film.
The panel shall be placed with one end elevated so that it is inclined 15° from horizontal. A buret
tip or other small (2 to 3 mm) glass tube shall be mounted vertically above the panel with the end
of the tube 50 mm above a point on the panel on its centerline and 25 to 35 mm from the upper
end. A one percent solution of pure sodium chloride in distilled water shall be allowed to drip
from the tube onto the lubricant film at 2 ± 0.2 mL/minute. Constant flow rate can be achieved by
siphoning the solution from a constant-level reservoir. After 100 mL of the solution passes over
the panel, it shall be examined with a 10X magnifier for evidence of rusting in the impingement or
drainage areas. Four such tests shall be made on the lubricant sample.
4.5.6 Rubber compatibility. The change in mass shall be determined by the general
procedure of ASTM-D471, Section 8, with the following specific provisions:
7
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business