- 34 -
First, determine what the system output should be when applying
the shunt resistance. In this case, Reference 1 (100 µe) is a good
choice (20% of Full Scale). To calculate the calibrated output of
the system, use the equation below:
Legend of Terms
V
S
Voltage Output with Shunt Applied (V)
ε
S
Strain Simulated by Shunt (µe, GF = 2.0)
ε
FS
Full Scale Strain (µe, GF = 2.0)
Z
Scale Factor (one if no scaling)
V
FS
Full Scale Voltage Output (V) (10V)
In this example, with Reference 1 applied, the calibrated Voltage
Output would be calculated as follows:
100 µe
(0.9802) (10 V) = V
S
= 1.9604 V
500 µe
Adjust the System Gain setting until the output matches this value.
The adjustment is typically small (<0.5%). The system is now
ready to measure torque with the desired output scaling.
NOTE: When the Gage Factor is not 2.0, the actual Full Scale
Strain and Simulated Strain values are affected proportionately. In
the example above with a Gage Factor of 2.08, Full Scale Strain is
technically 480.7 µe, not 500. However, the Simulated Strain is
likewise affected (Ref 1 becomes 96.14 µe, not 100). The ratio of
Simulated Strain to Full Scale Strain remains constant (20%) and
the calculation above remains valid.
Also, if the gage resistance is not 350Ω, the Reference 1 & 2
Simulated Strain values are not 100 and 500 µe, respectively.
Use our online calculator or the equation on page 33 to calculate
the simulated strain in this instance (use GF = 2.0).
ε
S
V
S
= (Z) (V
FS
)
ε
FS
Summary of Contents for TorqueTrak 10K-LP
Page 1: ...TorqueTrak 10K LP Torque Telemetry System User s Guide 869501 9_F ...
Page 2: ......
Page 45: ... 43 ...