BARTINGTON INSTRUMENTS
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In this configuration there is a voltage drop due to the cable’s resistance along the power ground.
Typical current is 25mA and the resistance of a 100m, 24 AWG cable is 5Ω, resulting in a drop
of 0.125V. Thus the reference point for the X, Y and Z outputs is 0.125V difference to the Host
0V, which is the source of power for the sensor. However, no current flows in the signal ground
conductor because the IAs have very high input impedance and no voltage is dropped in the 5Ω
resistance of either signal ground or X, Y and Z conductors.
Connecting sensors using this method means that the sensor outputs are accurately read by the
IAs, which then refer them accurately back to the 0V of the Host equipment.
