The CSR is used to confirm if current is present on shared wires. The CSR provides a 10Ω inline resistance, matching the internal impedance of the TRIMAX Direct Current Meter (DCM). It can be used to confirm multiple wires sharing current, by introducing it onto a suspect wire and then measuring the current on the alternative wire using the DCM or alternative multimeter. The current shift effect will be seen on the multimeter screen as the CSR is introduced and removed from the wire if it is sharing current.