The resister to be used (RZ) directly influences the zero drift characteristic of the
sensor, therefore use the resister that has an excellent temperature coefficient.
(25ppm/℃ or less recommended) This method can be used for sensitivity calibration
when the indicator is replaced.
In general, the initial calibration is done by combining with a sensor and an actual
applied load. However, when a re‑calibration is not feasible, it can be done with the
following substitution method without using an actual load.
After initial calibration, connect an appropriate resister (RZ) to one side of the
bridge and record the displayed value, then remove the resister. When the indicator
is replaced for a reason of servicing or so forth, connect the same resister used above,
adjust ZERO balance, and make a sensitivity adjustment so that the reading value becomes
the same as the previously recorded value.
The table in next page shows the resister values and the shift amount when a resister
is connected to one side of the bridge circuits having two different resister values,
350Ω and 120Ω. These resister values are calculated amounts and they may be off due
to the errors in the input and the output resistance of the sensor. Use these values
only as an estimate or guideline.
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