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9
Calibration
Torque Head
Calibrating the torque head provides a reference point for interpreting test
results. The calibration kit provided uses dead weight to simulate resistance
on the torque head. To calibrate, three different weights are applied and
the corresponding torque head readings are recorded. During operation,
compare the torque head reading to those recorded during calibration to
determine the amount of resistance being put on the torque head.
Before calibrating the torque head, test the container paddle for excessive
friction by running the sample container without any cement slurry in it. If
the paddle is bent and rubbing on the side of the slurry container or if the
bearings are damaged, excessive friction will show on the dial (refer to the
maintenance section on page 13 for more information). Correct any defects
before calibrating the torque head.
Calibration instructions are described in API-RP-10-B. Your instrument is
equipped with an instrument-mounted calibration unit.
1. Place the torque head onto the calibration stand.
2. Place the calibration ring around the torque head.
3. Wrap the deadweight calibration cord counterclockwise around the
calibration ring and over the roller.
4. Place 400 g on the weight hanger and attach it to the calibration cord.
Calibration Ring
Torque Head
Calibration Cord
Hanger and Weight
When adding weights, remember that the hook weighs 50 grams.
Therefore, to test the potentiometer at 200 g, you only need to add
150 g to the hook.
