David L Richmond

US Patent:

50019279, Mar 26, 1991

Filed:

Sep 25, 1989

Appl. No.:

7/412190

Inventors:

James E. LaCava - Novi MI
David C. Richmond - Jackson MI
Norman S. Martucci - Birmingham MI
Peter A. Hochstein - Troy MI

Assignee:

Teleflex Incorporated - Limerick PA

International Classification:

G08B 2100

US Classification:

73304C

Abstract:

A liquid sensing assembly (10) senses the level of liquid (18) in a container (12). The assembly (10) includes a reference sensing capacitor (16) for sensing the dielectric constant of the liquid and a level sensing capacitor (14) for sensing the level of the liquid with a dielectric factor. A housing (20) forms one plate of the capacitors (14, 16), and two separate coiled wires form the second plates of the capacitors (14, 16). The capacitors (14, 16) are located within the housing (20) and separated by a seal (46) to prevent liquid from passing therethrough. The reference capacitor (16) is located in the upper end (28) of the housing (20) and receives the liquid directly at an inlet (52) and fills to overflow at an outlet (56) into the container (12). The level capacitor (16) is in the lower section of the housing (20) to sense the level in the container (12).