20
5-5 BALANCING
Both resistive and capacitive signal components
*8
exist on a strain gage bridge. These unbalance
components should be removed through balancing, in order to achieve high quality measurement.
5-5-1 Balancing Range
Resistive unbalance can be reduced to ±2 %, i.e. ±10000 m/m.
Capacitive unbalance can be adjusted up to 2000 pF.
Resistive balancing is carried out by using the BAL switch.
Capacitive unbalance is cancelled all the time by the internal compensation circuit.
5-5-2 Balancing
Press the BAL switch on the front panel twice. This is all you have to do to execute balancing.
The monitor lets you know if or not balancing has been carries out correctly. The meter indication of
approximately 0 (zero) reflects correct balancing. An indication value within a range of ±10 mV can be
taken as normal. To adjust the meter indication to exactly 0 (zero), execute the zero point adjustment.
For details, read “4-6-4 Zero Point Fine Adjustment.”
After pressing the BAL switch, if a large value should appear, it is the indication of some error. Repeat
balancing a few times. Should it happen after that, discover the cause by referring to “7-2 INITIAL
BALANCING IS IMPOSSIBLE.”
Balancing can also be carried out by using the external control signal. For details, read “5-13 REMOTE
CONTROL.”
5-6 MOVING ZERO POINT
The zero point of OUTPUT A and OUTPUT B can be removed.
This function is conveniently used to move the base line of an external instrument.
For how to move the zero point, read “4-6-4 Zero Point Fine Adjustment.”
Zero point adjustment range is about ±50 mV from the balancing value.
The CPU controls to minimize remaining V during balancing the DPM-900/950 series. If one
time of balancing is not enough, repeat balancing a few times. In that case, one time of balancing
may require up to 5 seconds, but this does not reflect any error.
NOTE
The zero points of OUTPUT A and OUTPUT B move at the same time and same range.
The zero points of OUTPUT A and OUTPUT B cannot move independently.
NOTE
