Detector of two levels of electrically conductive liq. e.g. for water level control - has lower common reference electrode, and connects upper and lower electrodes of different electrochemical potentials together to form short-circuited battery when both are surrounded by liq.

摘要

Two electrodes (2,3) of metals having different electrochemical potentials are sited at upper and lower levels respectively and wired to an electronic control appts. (7), in conjunction with a reference electrode (1) on an insulated wire (8) for the potential at the lower level. An equipotential connection (4) for the upper electrode is provided by a stainless steel screw through the plastic coating of the brass or stainless steel tube (5) supporting the lower electrode. Complementary bipolar transistors (11,12) are used with a DC source (10). USE/ADVANTAGE - With pumping or electrical valve installations, e.g. at boreholes or premises having no natural drainage, only one wire is required to interconnect upper and lower electrodes to each other and to control system.