Common Connection Errors - Intab PC-logger 3150 How To Use Manual

3.5

Common connection errors

1) Ground loops:
Instrument with two Single Ended Outputs
Two apparently separate outputs from an instrument are each connected to a
channel. Both channels have the negative input shorted to ground via the
"Diff/Gnd"-switches.
Measured values may be either unstable or inaccurate.
Solution: break the ground loop by putting one of the switches in the "Diff"
position.
2) Floating signal : no connection to system ground
A signal equivalent to a common flashlight battery is connected to + and - of
one of the channels. Readings are unstable.
Solution: give this signal a proper ground reference by shorting the negative
input to logger ground by placing the Dip-switch in the "Gnd" position.
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INTAB Interface-Teknik AB