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3. Calibration
008-0738-00
Calibration Example:
To calibrate from –100 to +100 Nm in five steps of -100, -50, 0, +50 and +100 Nm:
Set #CalSteps=5
#CalReset
•
Apply -100 Nm and set #CalValue1=-100,
•
Apply -50 Nm and set #CalValue2=-50
•
Apply 0 Nm and set #CalValue3=0
•
Apply +50 Nm and set #CalValue4=50
•
Apply 100 Nm and set #CalValue5=100
To obtain a frequency output of 5 kHz at 10 Nm and 15 kHz at 80 Nm then the parameters
would be #AnOutLow=10 and #AnOutHigh=80.
The device will then be fully calibrated. Note that for best results and to conform to accepted
calibration practice, the unit under test should be exercised three times at the full load in the
direction of loading prior to the setting of calibration points. This is especially important when
calibrating in both the clockwise and the counterclockwise directions. Please contact the
factory for a detailed description of calibration practice and procedure.
If an alternative analog output is selected at a later date, or if different settings are chosen for
the #AnOutHigh/Low parameters later, it is not necessary to repeat the loading calibration
because all analog outputs are digitally driven.
3.2
Shunt Calibration
An electrical signal equivalent to that produced by a known load can be obtained by activating
the SHUNT CALibration function. The SHUNT CALibration function is built in to the sensor
itself, and it is therefore necessary for the Rotor Active light to be showing before the function
can be operated. By design, the caliper coupling module is more sensitive to receiving data
than it is to transmitting data, therefore it may be necessary to adjust the caliper coupling
module position to ensure good two-way communications, prior to using the SHUNT CAL
function.
The SHUNT CALibration function is achieved by connecting a high-precision resistor of know
value, in parallel (shunt) with one arm of the strain gage Wheatstone bridge. The connection is
made by a solid state switch, under the control of the microprocessor on the rotating sensor,
when commanded by the remote Signal Processing Module. This switch can be activated via
the pushbutton on the face of the signal processing module. The SHUNT CALibration value
is determined during factory calibration of the torque sensor.
The SHUNT CALibration function is a very useful aid when setting up the system or when fault
finding. This function can be used as an alternative in applications where it is neither possible
nor practical to perform dead weight system calibration. However, there can be some loss of
calibration accuracy.
3.3
Recalibration
Recalibration should follow normal instrumentation certification schedule.
32
TMS 9250 Product User Manual
© 2012 – Honeywell International Inc. All rights reserved
Rev B
April 2012
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