LISN-CISPR25-200 LISN

Interference voltage measurements (CISPR 25)

Mains is connected at the back side. The 1µF capacitor must be switched on to filter external disturbance and to provide best isolation values. The DuT is connected to the front panel. The disturbance voltage is coupled to them N-type connector where it can be measured with an EMI receiver. For this purpose the switch at the front panel must be switched to “Measure”. In most cases one AMN has to be used for each line (e.g. + and -). The RF-reference ground must be connected to both GND-terminals. 

The 4 mm laboratory jacks at front- and back panel and the flat aluminium feet are electrically connected to the GND-terminals.

Immunity tests with bulk current injection (BCI-tests):
The LISN-CISPR25-200 can be used for bulk current injection tests and disturbance voltage measurements utilizing a clamp-on ammeter. The maximum continuous power rating is 50 W (at the EuT-terminals). With a continuous power input of 50 W the LISN housing heats up to approx. 60° C at the front panel. The operator must be aware of high temperature. 

During bulk current injection tests dangers may arise by high field strengths and temperatures (fire hazard!), therefore these tests must be performed by qualified personnel only! The relevant safety precautions must be considered!

Usually the switch position "50 Ohm Termination" is used for BCI-tests. The power injected at the EuT-terminals is converted to heat inside the 50 Ohm / 50 W resistors.

Transient measurements (ISO 7637-2 and ISO 7637-4)
The LISN-CISPR25 can be used to measure transients according to ISO 7637-2. The 1 µF capacitor on the mains side could short transients and must be switched off for this purpose.