The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 01, 1986
Filed:
Jul. 30, 1984
Daniel J Soltz, Norristown, PA (US);
Fischer & Porter, Warminster, PA (US);
Abstract
An ultrasonic, echo-ranging instrument for measuring the level of liquid in an open channel or tank. The instrument includes a transducer disposed at a fixed position directly above the liquid surface, the nature of the gaseous environment therebetween determining the velocity of ultrasonic energy propagated therethrough. The transducer is excited to emit periodic pulses which are intercepted by the liquid surface and by a reference point a fixed distance from the transducer to produce both reference and liquid echo pulses that are returned to the transducer and detected thereby. The respective transit times of the reference echo and the liquid echo pulses are determined, and the ratio between these transit times is computed to provide an output representing the level of liquid independent of changes in the gaseous environment. To ensure accurate readings, the reference echo and liquid echo pulses from the transducer are fed to a single automatic gain control circuit whose operation is time shared. The circuit is enabled in a reference mode having a predetermined duration to effect gain control for the reference echo pulse and is thereafter enabled in a target mode having a predetermined duration to effect gain control for the liquid echo pulses.