BUSHING-TERMINAL 9D4784 - Caterpillar

Shunt Calibration
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The Shunt mode is indicated by shn in the lower left of the display, as shown in the illustration above. This mode does not apply to testing but to the calibration of the testing unit and is used to verify the accuracy of force readings.The tester should be warmed up and the force display zeroed in the Manual mode before entering the shunt calibration mode for verification. Make sure that the unit of measurement is the same as the Shunt Value recorded on the Calibration Report from the factory. When the shunt calibration mode is activated, a load is electrically simulated and generates a force reading on the display. Compare the force value displayed in the underlined field shown in the example below with the Shunt Value recorded on the Calibration Report shipped with the tester. The two numbers should match or be relatively close. Contact Larson Systems if there is a notable discrepancy.Force and Length Initialization
The force and length displayed must be initialized (zeroed) at a reference point to achieve consistent results. This should be done prior to testing.The normal reference point for force is with the platforms apart and no load (spring) on the lower platform. Force initialization may need to be done after the normal initialization with the sample spring resting on the lower platform. This ensures that the weight of the test spring is not included in the force measurement. The test procedure includes this step.The normal reference point for length is with the upper and lower platforms together (compression), with force applied.If stop rods are part of the tester assembly, make sure that the rods are set to permit free travel of the upper platform before initializing.
Turn on the tester and move the upper platform all the way upward.
There should be no force applied and nothing resting on the lower platform.
Press (ZERO FORCE). The force display should read zero.
Bring the upper platform down to meet the lower platform.
With the platforms together and applying 10% to 30% full-scale force, press (ZERO LENGTH).Testing Procedure
Preparation
Turn on the tester and allow the tester to warm up for at least 30 minutes prior to testing.
Check out the operating condition of the tester. Make sure the upper assembly moves freely and all parts are in working order.
Exercise the machine in the way that testing will be done to facilitate the most accurate readings.
Leave the tester in Manual mode to begin.Compression
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Choose the unit of measurement to be used for testing by pressing UNITS.
Initialize both force and length for compression per instructions.
Place head in contact with spring and remove handle. Then press (ZERO FORCE). This deducts the weight of the spring from the force measurement.
To test in Peak mode, press (MODE). The lower left of the display reads, pk. Otherwise, remain in Manual mode and begin testing with the next step.
Perform test by applying compressive force to sample using the handle on the upper rack assembly. Use the standards you previously determined appropriate for desired results to