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Gain
5.2.1 Correction of the analogue current output
The calibration of the amplifier in general is done with the
potentiometers on the front. This basic calibration adjusts the
analogue voltage output. The analogue current output follows
the voltage output. Thus, the analogue current output does not
need to be corrected – it is been done right in the factory. If,
however, the current output does need an adjustment, it can be
done by 2 potentiometers inside the amplifier.
5.2.2 Calculation of the amplification determing resistor
The amplification is:
G
total
= G
differential amplifier
x G
output stage
The amplification of the output stage is adjustable with the potentiometer P-02 (GAIN). The adjustable
range is:
G
output stage
=
9,5 … 10,5 Volts
Calculation of the coarse amplification resistor R
G
(applies for 10 Volts output):
G
differential amplifier
=
1000 mV
Exc. (V) x Signal (
mV
V
)
R
G
=
50 kOhm
(G differential amplifier –1)
Example:
Transducer:
2,5000 mV/V (0,0025V/V)
Excitation:
10,000 V
the 2 resistors
R
G
=
50 kOhm
(
1V
10 V x 0,0025 V
-1)
=
1282 Ohm
Zero
