Calculating Methods Applicable To Strain Gage Transducer - KYOWA DPM-900 Series Instruction Manual

9-3-4 Calculating Methods Applicable to Strain Gage Transducer

A strain gage transducer measures a physical quantity such as load, pressure, torque, displacement,
acceleration or other after conversion into electric signals through strain gages.
The DPM-900/950 series is designed to measure strains. The amount of a measured strain has to be
converted into a physical quantity by using the calibration factor or the rated output stated in the Test Data
Sheet of the strain gage transducer.
1) Calculating method using a calibration factor
Multiply the amount of strain obtained using the strain gage transducer by the calibration factor stated
in the Test Data Sheet of the strain gage transducer to obtain the desired physical quantity.
<Example> Suppose that a measurement of 2900 m/m was obtained using a load cell with capacity of
20 kN (2.0394 tf) and calibration factor of 0.004997 kN (0.00051 tf)/ m/m.
A load given to this load cell can be calculated as follows.
0.004997 × 2900 = 14.4913 [kN]
2) Calculating method using a rated output
An output value (or a rated output or output voltage sensitivity) against a rated load is stated in the
Test Data Sheet of a strain gage transducer. The following examples show how to obtain the reading
of a physical quantity given to a strain gage transducer through adjusting the stated rated output as
well as the dynamic strain amplifiers' calibration factor and output.
<Example> Using the combination of: pressure transducer with capacity of 490 kPa (5 kgf/cm
output of 3993 ɛ.
Set the CAL switch of the DPM-900/950 series to 3993 m/m (rated output of the transducer)
or set the VOLTAGE OUT switch to output 10.00 V. Press the SET switch twice to set the
internal gain. After that, apply pressure to the transducer. 10.000 V will come to correspond to
490 kPa.
<Example> Using the combination of: acceleration transducer with capacity of 196 m/s
output of 850 m/m and the DPM-900/950 series
Set the CAL switch of the DPM-900/950 series to 850 m/m (rated output), set the VOLTAGE
OUT switch to 10.00 V and press the SET switch twice to set the internal gain. Then 10.000 V
will come to correspond to 196 m/s
Suppose a recording meter is used. If calibration value of 850 ɛ is entered, adjust the
vibration width of the recording sheet to have 20 mm or 200 mm. Then, the amount of the
vibration width will come to correspond to 196 m/s
2
(20 G).
2 (20 G).
49
2
) and rated
2 (20 G) and rated