Patent ID: 6098457
Filing Date: 2000-08-08
Classification: G01F

Abstract:
A fluid level detector for being immersed in a fluid and thereby determining the fluid level, comprising:a) a substrate formed of a heat-insulative material;b) at least one thermoresistive sensor element located on the substrate to form a, having a resistivity that changes substantially linearly in response to temperature change;c) a current source, connected to the sensor element, for producing a current Through the sensor element for a predetermined time period to thereby heat the sensor element during the predetermined time period, the current source producing a voltage across the sensor element at least during the predetermined time period;d) means for measuring the voltage across the sensor element during the predetermined time period and for determining a voltage slope that varies relative to the amount of the sensor element that is immersed in the fluid;and means for monitoring the voltage across the sensor element subsequent to the predetermined time period for determining a stable condition of the sensor element.