Shunt CALIBRATION

Calibration with the Shunt Resistor
Attach a shunt resistor in parallel with one arm of
the gauge to produce an output signal simulating
strain.
1   K
Rc  Rg 
 K
There are two methods to
attach the shunt cal resistor.
Rc : Shunt cal resistor
Rg : Gauge resistor
K : Gauge factor
 : Reference strain (uSTR)
Auto- balance :
Cancel the initial offset value
Shunt-CAL :
Adjust the Gain modulus of the gauge
Positive strain direction
Negative strain direction
Shunt CALIBRATION
Shunt Calibration will be performed by linear scaling function.
P1:Y set depends on the initial offset value but usually 0.
P2:Y Reference strain (uSTR)
After the above setting done, press the “Shunt Cal” key…
P1: X DL sets the value using “get measure” function
when releasing the shunt cal resistor
1   K
Rc  Rg 
 K
P2: X DL sets the value using “get measure” function
when attaching the shunt cal resistor
ex. Shunt cal resistor(Rc) and Reference strain( P2:Y)
Rc (k Ω)
Rg

( Rc  Rg )  K
10
15
33
100
330
Reference strain (ε: uSTR)
Rg = 120Ω
Rg = 350Ω
5928.9
16908.2
3968.3
11400.7
1811.6
5247.4
599.3
1743.9
181.8
529.7 When K=2.00
Shunt CAL procedure

Calibration procedure 1
1. Connect the strain module, 701271, the
bridge head, 701957/701958 and the strain
gauge. Attach the shunt resistor on the
bridge head.
2. Set the range unit, the range, the excitation
voltage and gauge factor
3. Implement the Auto-Balance function.
Shunt CAL procedure

Calibration procedure 2
4. Normally enter 0 for P1:Y.
5. Enter the reference strain value
corresponding to the attached
resistor for P2:Y.
6. Enter the “Units”
7. Press “Shunt Cal” to perform the
calibration.
Shunt CAL procedure

After the calibration, P1:X
and P2:X values have
changed.
Shunt CAL procedure

After the calibration is done, the
Upper Scale and Lower Scale are
slightly changed. Both settings are
adjusted for convenient display.
Shunt CAL procedure

When the negative strain
direction is selected, the
P2:Y value must be negative,
and the calibration result,
P2:X will also be negative.