17 of 35
6 Setting the amplifier
6.1 Sensor excitation
The sensor excitation voltage is asymmetric and referenced to ground. This also allows the
shield of the sensor cable to be connected to the negative sensor feed. The excitation voltage is
supplied via a 4-wire cable. This means that the voltage drops in the excitation lines can be
compensated, provided that appropriate sensors are in use and the probe lines are connected.
Only use 6-wire extension cables. The excitation lines and probe lines in the plug on a 4-wire
sensor are bridged in each case. In the case of a 6-wire sensor, the two sensor lines are
generally routed directly to the sensor element, so that bridging is not required.
The following excitation voltages can be set:
2.5 V, 5 V and 10 V
The default excitation voltage of 5 V can be used to operate most sensors. If 2.5 V or 10 V are
selected, the device needs to be readjusted. The sensor excitation voltage is short-circuit proof;
the maximum current consumption is 35 mA.
6.2 Zero Point
The zero point is adjusted with a potentiometer (zero) which can be accessed via a bore in the
front panel.
The adjustment range of the potentiometers can be set with 2 DIP switches. The switch settings
are described in Chapter 4.1.3 titled Meaning of the DIP switches Page 13. If both switches are
OFF, the adjustment range is smallest. If both switches are ON, the adjustment range is largest.
The switches can be set in any required combination, so that asymmetric adjustment ranges are
also possible.
The zero point is adjusted between the second and third amplification stages. If the adjustment
range is too small, the gain can be decreased in stage 2 and increased in stage 3. If the
adustment range is too large, the gain can be increased in stage 2 and decreased in stage 3
(refer to Chapter 10.2 titled Block schematic Page 30).
To Next Page
Loading...