SM0486
b. When the range switch is positioned for a particular wrench test,
the indicator scale to be read is illuminated.
c. Adjust the zero know of range selected for a zero indication on the
dial.
(Do you understand why? If not, consult the function column of Table 2.)
d. Place the square drive of the torque wrench to be tested in the
square opening of the torque cell. Use an adapter if necessary.
e. Loosen the knurled thumb nut of the stop and slide the stop along
the slider bar until the stop is positioned at the approximate center of the torque
wrench handle.
(2) Before we proceed with the calibration preparation, let us be sure that
the two preceding steps are understood. Examine Figure 12 and Table 2 as you read
these steps again. Proceeding with steps in the calibrator preparation:
a. Tighten the stop thumb nut (horizontal adjust--Figure 12).
b. Loosen the wingnut and move the adjust block vertically until the
torque wrench is approximately level. (See Figure 12.)
c. Tighten the wingnut.
d. If the torque wrench handle is not positioned against the stop
(minimum amount of slack), it will be necessary to remove the wingnut and screw and
reverse adjustment block.
e. Set the torque wrench to the required setting for testing.
(3) When you compare the preparation steps with the actual test procedure
you should realize that the preparation of the calibrator for a test is as
important as the test. Before you start the test, you must check to be sure that
the calibration shutoff valve is open (see Figure 9 and Table 2).
Follow the
calibration procedure closely so that you can move the torque actuator switch to
its RELEASE position the moment clickoff occurs. If you don't move the switch of
the RELEASE at clickoff, the torque wrench under test may be damaged.
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