NRS 1-7 is a two-channel unit provided with an automatic self-checking circuitry in accordance with DIN VDE 0116 (directives for protection circuits). The self-checking is effected periodically. The
test includes the checking of the cable between electrode and level switch and the self-checking circuitry (redundancy). The output relays are not influenced by the internal tests.
(Obsolete, replaced by Gestra Low Level switch Type: NRS 1-50)