Potentiometer and electrical contact liquid level indicator - has metal contact fingers with plastic coating which expands on immersion in liquid

摘要

The level indicator consists of a resistance element (11) and a multiple contact blade (12). The resistance element may be a printed circuit and is arranged as a potentiometer with multiple tappings (22). The ends of the resistance are connected to an external supply and measurement unit (30) via terminals 24) and connectors (18). The multiple contact blade encloses the resistance element (11) on both sides with contact fingers (14a) (14b) and each finger has an external coating of a plastic which will expand when immersed in the liquid whose level is to be determined. This expansion cuses the associated contact finger to bend and its tip (15) to touch one o the resistance contacts (22). The liquid level can then be found from a resistance measurement. USE/ADVANTAGE - In vehicle there is no mechanical linkage to cause jamming and little wear in operation.