초록 ▼

A liquid level measuring system having a tubular ultrasonic probe with a length in excess of the depth of liquid to be measured; for vertical insertion into a tank. A transducer inside the tube, at a first distance above the bottom end of probe body, responds transmits a sinusoidal acoustical pulse

A liquid level measuring system having a tubular ultrasonic probe with a length in excess of the depth of liquid to be measured; for vertical insertion into a tank. A transducer inside the tube, at a first distance above the bottom end of probe body, responds transmits a sinusoidal acoustical pulse through the probe to the surface of the liquid. An echo returns from the surface of the liquid to the transducer and provides a sinusoidal echo signal. A receiver responds to the echo signal by providing a start signal corresponding to the transmitter signal crossing a predetermined amplitude in a predetermined direction and by providing a stop signal corresponding to a first selected echo signal crossing a second predetermined reference level in a predetermined direction. The speed of sound in the liquid is measured by measuring the echo time to a calibration rod in the tube at a known distance from the transducer. A timer measures the time between the start and stop signals and provides the time to a sequential controller. The depth of the liquid and the leak rate of the tank are calculated for display.

대표청구항 ▼

An ultrasonic probe for insertion into a tank for the measurement of the depth of petrochemical liquid stored in the tank, and for the detection of leaks in the tank in excess of a predetermined limit, the probe comprising: a substantially cylindrical probe body having a top end and a bottom end, an

An ultrasonic probe for insertion into a tank for the measurement of the depth of petrochemical liquid stored in the tank, and for the detection of leaks in the tank in excess of a predetermined limit, the probe comprising: a substantially cylindrical probe body having a top end and a bottom end, and a length in excess of the depth of liquid to be measured, the probe body having a back ranging target at the bottom end of the body, the probe body being made of a high thermal resistance material; means for holding the probe body in a substantially vertical position within the tank, the probe body extending downward vertically through the surface of the liquid, the bottom end of the probe body being held in contact with the base of the tank; transducer means positioned within the probe body at a first distance above the bottom end of the probe body for transmitting bi-directional pulses along the longitudinal axis to the surface of the liquid and to the bottom end of the probe body, the back ranging target being positioned to reflect a portion of the bi-directional pulses back to the transducer, and the transducer being operable to receive echoes from the back ranging target and from the surface of the liquid; and at least two calibration rods within the probe body, between the transducer and the top end of the body, each calibration rod being positioned at a successively greater predetermined distance from the transducer, and each respective calibration rod having a larger reflective surface.