The NNB 21 line impedance stabilization network from Langer EMV-Technk GmbH is designed for measuring grid bound interference of a device under test, in accordance with the CISPR 25/ISO 7637 standard.

The NNB 21 line- impedance stabilisation network is designed for the measurement of grip bound interference emissions in wiring systems (automotive sector) and also for general use. Two circuits can be measured at the same time or separately. It measures the RF interference, which couples into the vehicle electrical system and measurements in the 100 kHz to 1 GHz frequency range can be carried out.

The measurement setup does not need to be changed. Measurement errors are minimised. If there are measurements on just one signal line, the second signal path can be grounded via a side switch on the NNB 21. With 10 dB attenuation the supply of one source ≠ 50 Ω (common case) achieves significantly improved adaptation and reliable measurement results.