ASTM D2625 Test Method for Endurance (Wear) Life and Load-Carrying Capacity of Solid Film Lubricants (Falex Pin and Vee Method)
8. Preparation of Apparatus
8.1 Thoroughly clean the jaw supports for the vee blocks and test journals, by washing with the solvent selected from 7.2.2, of all debris or oil from previous test runs. See Note 3.

8.2 Avoid contact with the fingers of the mating surfaces of the vee blocks and test pins.

8.3 Avoid atmospheric contamination such as cigarette smoke, as this can adversely affect the test results.

9. Calibration of Load Gage
9.1 Calibration Procedure with 4500-lbf (20 000-N) Load Gage:
9.1.1 Remove the Allen set screw and 12.70-mm (1/2-in.) ball from the left jaw socket (Fig. 4).

9.1.2 Insert the special Allen screw with the attached 10-mm Brinell ball into the working face of the left jaw. Adjust so that the ball projects about 4 mm (5/32in.) from face of the jaw.

9.1.3 Insert the back-up plug in the counterbore of the right-hand jaw. Adjust so that the plug projects about 0.8 mm (1/32 in.) from the face.

9.1.4 Support the standard test coupon so that the upper edge of the coupon is about 2.5 mm (3/32in.) below the upper surface of the jaws. Place a steel rule across the face of the jaws. Adjust the Allen screw with the attached 10-mm ball until the face of the jaws are parallel to the steel rule with the test coupon in position for indentation.

9.1.5 With the test coupon in position for the first impression, place the load gage assembly on the lever arms.

9.1.6 Place the loading arm on the ratchet wheel and actuate the motor. Allow the motor to run until the load gage indicates a load of 300 lbf (1330 N). A slight takeup on the ratchet wheel is required to hold the load due to the ball sinking into the test coupon. After the 300-lbf (1330-N) load is obtained, hold for 1 min for the indentation to form.

9.1.7 Turn off the machine and back off the load until the test coupon is free of the jaws. Advance the test coupon approximately 9.5 mm (3/8 in.) (additional indentations should be separated by a minimum distance of 2.5 x the diameter of the initial indentation). Check the alignment of the jaws, and repeat the procedure described in 9.1.6 at gage loads of 750, 1000, and 1500 lbf (3300, 4450, and 6650 N).

9.1.8 Remove the load gage assembly and test coupon and measure the diameter of each indentation to 0.01 mm with the Brinell microscope. Make three measurements of the indentation diameter, rotating the test coupon to ensure that no two measurements represent the same points. Average the three measurements of each impression and record.

9.1.9 Plot the four impression readings versus gage load readings on log-log paper (K&E 467080 or equivalent). If they do not plot as an approximately straight line, repeat steps 9.1.4-9.1.8. A standard curve of impression diameter versus gage reading is shown in Fig. 3. If the indentation diameter, plotted as above, is lower or higher than that shown on the standard curve, determine the actual load necessary to produce the indentation diameter that will correspond to that shown on the standard curve.

NOTE 4 - A full-size standard calibration curve, plotted on log-log paper and similar to Fig. 3 but with finer subdivision lines included, should be used for accurate calibration.

9.2 Calibration Procedure with 800 or 3000-lbf (3550 or 13 300-N) Direct-Reading Load Gage:
9.2.1 Use the same procedure as with the 4500-lbf (20 000-N) gage above, except obtain impressions at gage readings of 300, 500, 700, and 800 lbf (1330, 2220, 3100, and 3550 N) on the 800-lbf (3550-N) gage; or at 300, 700, 1100, and 1700 lbf (1330, 3100, 4880, and 7550 N) on the 3000-lbf (13 300-N) gage. Plot the impression readings versus gage load readings, as in 9.1.9, with similar adjustments to the load in order to produce indentation diameter that corresponds to the indentation diameter on the standard curve.