How can you measure very small currents with the AC Interface?
The AC interface (ACI) has been designed for operation with up to 10A RMS supplied to the transformer under test.
In some applications - e.g. measuring transformers, the AC Interface is required to supply higher voltages (600V) but it is necessary to check for a small magnetizing current (e.g. 10uA at 10V). The 20:1 CT supplied with the AC Interface is ideal for high currents, but will introduce errors when measuring small currents.
To overcome this problem, simply replace the CT with links as described in the attachment “AC Interface connections for measuring low currents”.