Silicon based low level liquid sensor having a fast response time

摘要

A low liquid level sensor fabricated on a silicon substrate having four temperature dependent elements formed thereon in a Wheatstone Bridge configuration. A thin, wire-like extension of the substrate between two openings within the substrate provides a mounting member for the fourth element. The other three elements are spacially separated from the fourth element such that the fourth element becomes exposed to air during a low liquid level condition while the other three elements remain submerged within the liquid. Accordingly, the Wheatstone bridge configuration and relative positioning of the elements on the substrate eliminates the need for corrections due to temperature variations and power supply fluctuations.