Ultrasonic system for measuring fluid impedance or liquid level
US4320659A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1980 |
| Grant date | Mar 23, 1982 |
| Priority date | — |
| Expiry date | Jan 11, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/02836
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ultrasonic system that measures either the impedance of a fluid or liquid level utilizes moderately directional, bulk SV mode sound waves generated by a transducer and propagated in a homogeneous, flaw-free solid member. The SV wave propagates in the solid along a zigzag path that reflects at a solid-fluid interface in at least two areas and at an angle of incidence that exceeds the first critical angle by at least five degrees and is less than the second critical angle by at least ten degrees. The attenuated amplitude of the wave due to acoustic coupling between the solid and the fluid measures the impedance or an impedance related parameter of the fluid. The system preferably includes a second acoustic path that serves as a reference to compensate for changes in parameters such as temperature, the nature of the fluid, the transducer, the transducer coupling, and residues or corrosion at the solid-fluid interface. In another form, the reference mechanism is a series of reflections from notches in the solid member. For liquid level measurement desensitized to variations in the liquid impedance, the solid is an elongated member that is oriented at an oblique angle, or is parallel…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.