Balancing And Adjustment; Bridge Excitation Voltage; Zero Balancing - HBM MC2A Manuel D'emploi

14
4

Balancing and adjustment

The measuring amplifier is ready for operation immediately after switching on
the supply voltage.

4.1 Bridge excitation voltage

2 V (rms)
The bridge energizing oscillator of the measuring amplifier produces a sine
wave of 2 V " 3 % at a frequency of 5 kHz, which is symmetrical about earth.

4.2 Zero balancing

Up to "9 mV/V
The zero balancing range is set, as a standard, to " 9 mV/V
ously covered by the screw driver potentiometer P 21. This range is indepen-
dent from the impedance of the transducer connected. When adjusting clock-
wise the bridge will be tuned in the positive sense.
Owing to the principle of measurement of inductive transducers it is necessary
to set the connected transducer to its mechanical zero position prior to mea-
surements. The residual unbalance may then be cancelled by the zero bal-
ance facility.
The zero balance range can be reduced to 0.9 mV/V by replacing resistor
R 21 with an appropriate value calculated by the following:
Rx + 138.6
kW
A
A = selected range in mV/V
*)
At the customer's request, the zero balancing range can be increased to 80 mV/V at the factory. A fixed
tare value as specified by the customer upon ordering can be adjusted a the factory.
HBM
MC2A
*)
and is continu-
A1974−2.2 en/de/fr