Version 2.1
en MBI 46.31 operating instruction.docx
Issue date: 01/2022
Page 9 of 42
Signal output of the measuring amplifier
(Nominal)
output range
The (nominal) output range of the measuring amplifier
indicates the range covered by the output signal, if the
displacement sensor operates in the (nominal) measuring
range.
Current output Analog current output of the measuring amplifier:
typically 4...20 mA for the nominal stroke
Voltage output Analog voltage output of the measuring amplifier:
a) typically ±10 V for symmetric displacement sensors
b) typically 0...10 V for asymmetric displacement sensors
4.2 Function and design
The MBI 46.31 generates the AC voltage (excitation voltage U
sp
) required for
operating inductive displacement sensors. The frequency (carrier frequency) is
typically 5 kHz (optionally 1...20 kHz).
The output signal proportional to the displacement (the measurement voltage)
returned by the displacement sensor is preamplified by the measuring amplifier
and evaluated ratiometrically, i.e. in relation to the excitation voltage. This way
measurement errors are avoided that result from fluctuations of the excitation
voltage, e.g. due to an impedance change of the displacement sensor.
In subsequent stages, the measurement signal is filtered and scaled to the
desired output range for further processing.
