Kipp & Zonen CT24 Instruction Manual page 13

CONNECTION OF THE CT24
The passive Kipp & Zonen sensors have floating outputs
(not connected to sensor housing or shield), so the inputs
of the CT 24 will be floating.
Actually the rule of thumb is that any connection
between CT 24 input LO and output LO is not allowed
(e.g. accidentally both grounded).
In case of doubt check the impedance of the sensor wires
against the sensor housing, this should be infinite.
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