Patent ID: 7421895
Filing Date: 2008-09-09
Classification: G01F

Abstract:
1. In a fluid tank wherein said tank is susceptible to movement, and wherein a calibration fluid level in said tank is known, an improved ultrasonic fluid level sensor comprising: a stillwell having a vertical mount in said tank; said stillwell having a segment extending above a maximum level of said fluid; said stillwell having a hole at a bottom segment to provide a fluid communication between a tank fluid level and a stillwell fluid level; an ultrasonic transducer mounted in said stillwell; wherein a fluid level indicator is set at the known calibration fluid level and a calibration signal is sent from the transducer to the known calibration fluid level and back to the transducer, thereby creating a reference time measurement of the calibration signal which corresponds to the fluid level indicator setting; and wherein subsequent variations in the fluid level are indicated on the fluid level indicator in a predetermined relationship with subsequent reference time measurements.