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In the example from Step 1 above, Full Scale Torque (T
FS
) has
been calculated to be 4,901 ft-lb. It may be convenient to scale
the output so that 10 V indicates 5,000 ft-lb (1 V = 500.0 ft-lb).
First, calculate the Scale Factor (Z):
4,901 ft-lb
= Z = 0.9802
5,000 ft-lb
Next, multiply the Scale Factor times the Transmitter Gain setting
to find the System Gain setting.
4000 x 0.9802 = 3920
Scroll to the Gain parameter screen on the RX10K and set the
System Gain to 3920 (see page 9). In summary:
Before adjusting full scale output:
4,901 ft-lb = 10.000 V (490.1 ft-lb/volt)
After adjusting full scale output:
5,000 ft-lb = 10.000 V (500.0 ft-lb/volt)
Step 3: Calibrate the Output
There are two ways to perform a calibration of the installation: a
deadweight calibration or shunt calibration.
Deadweight Calibration
The most precise method is to perform a deadweight calibration.
This involves suspending a known mass a known horizontal
distance from the center of the shaft. This is not always practical
but does take into account all possible deviation in the system
(actual material properties versus data sheet, shaft geometry,
gage imbalance, etc.) With the known moment applied, adjust the
System Gain until the output is the same as the calculated torque
value.
Using the parameters outlined in the previous example, a
deadweight is applied to the gaged 3-inch shaft that corresponds
to 500 ft-lb of torque. The System Gain would be adjusted until
the output was equal to 1 volt. NOTE: It is recommended that in
order to be meaningful, the deadweight should create a torque
Summary of Contents for TorqueTrak 10K-LP
Page 1: ...TorqueTrak 10K LP Torque Telemetry System User s Guide 869501 9_F ...
Page 2: ......
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