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 393 of 460

FED-STD-791D

6.1.5 The data acquisition and control system consists of a HP data acquisition

and control unit, a HP computer as system controller and the user operation program

(LOWTEMP). The HP data acquisition and control unit also contains three plug-in

assemblies: relay multiplexer assembly for measuring the torque value, relay multiplexer

assembly with thermocouple compensation, and high voltage actuator to control the drive

system.

6.2 Laboratory oven, gravity convection, 70 �3 �C.

6.3 Grease packer, as described in the ASTM D 3527 test method.

6.4 Spindle holder or test preparation stand.

6.5 Ultrasonic cleaner.

7. CALIBRATION

7.1 Torque calibration. Attach a support disk (diameter: 4 cm), for holding the

dead weight, on the top of the rod. Measure output (millivolt) of load cell as a known

force (dead weight: 0.5 kg, 1-10 kg) is applied to load cell at the room temperature.

Then, the calibration equation shall be determined using the statistic method. The

Method of Regression analysis is very suitable to develop the torque calibration equation.

The typical calibration curve is shown in figure 2. This calibration needs be done only at

the time of initial setup and when occasional checks indicate that it is required.

7.2 Temperature calibration, as described in ASTM D 4693, or equivalent.

7.3 Spring calibration, as described in ASTM D 4693, or equivalent.

8. TEST BEARINGS.

8.1 Use LM67010-LM67048 and LM11910-LM11949 inboard and outboard

bearings, respectively. Timken bearings are suitable. Prior to use in this test, new

bearings shall be conditioned by installing any suitable wheel bearing grease in the

bearings and running them at room temperature for 48 hours at 1,000 rpm under a normal

thrust load of 111 N. ASTM D 3527 test apparatus is suitable for conditioning the

bearings.

Note 1. The bearings must be keyed to prevent race rotation on spindle.

9. PROCEDURE

9.1 Clean the test bearings with heptane or equivalent reagent using a ultrasonic

cleaner and dry with compressed air.

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