Gamry Instruments Interface 1000 Operator's Manual page 74

Caution:
Floating Ground. Connection of signal to an earth-ground-referenced apparatus can compromise the
Interface 1000's ability to float, and invalidate data collected on earth-grounded cells.
The E Monitor signal is filtered using an RLC circuit. It has a bandwidth of approximately 150 kHz when
connected to a high-impedance input. This bandwidth will be further reduced if a coaxial cable is connected to
the BNC. Its output impedance is approximately 1 kΩ in parallel with 47 pF.
External Signal In
External Signal In allows you to add a voltage to the Interface 1000's Signal Generator. It is a two-wire
differential signal with the negative side connected to the Interface 1000 floating ground. This signal is summed
with the other signal-generator sources, including the Bias DAC, the Scan DAC, and the DDS output.
Caution:
1000 Floating Ground. Connection of signal to an earth-ground-referenced apparatus can compromise the
Interface 1000's ability to float, and invalidate data collected on earth-grounded cells.
The signal generator output is directly connected to the potentiostat's input. When the cell is turned on in
potentiostat mode, the feedback is such that a negative signal-generator output creates a positive differential
electrometer signal, which corresponds to a negative working electrode versus reference electrode voltage.
The polarity of the External Signal In signal is inverted at the signal generator's output. As described above, a
negative input signal on this input will create a positive change in the working electrode versus reference
electrode voltage. The input impedance of this signal is 2 kΩ.
Appendix C : I/O Connectors--Monitor Connector
The negative side of the E Monitor signal is connected to the Interface 1000
The negative side of the External Signal In signal is connected to the Interface
Appendix C - 4