Method and apparatus for ultrasonic material level measurement
US4000650A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 20, 1975 |
| Grant date | Jan 4, 1977 |
| Priority date | — |
| Expiry date | Mar 20, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S367/901
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Ultrasonic pulses are transmitted from the top of a tank or bin by a transducer and reflected by the material contained therein and received by the same transducer. In the short range mode, two millisecond pulses at sixty second intervals provide a measurment of from two to twenty one feet. Failure to detect a reflected pulse in the short range mode automatically switches the device to the long range mode utilizing ten millisecond pulses at three hundred millisecond intervals. After a pulse is transmitted the energy received by the receiver is converted to a digital value each millisecond and compared to the highest previously converted digital value so that the time of the largest received reflection signal and consequently the distance to the material surface may be determined. The echo signals from eight successive long range pulses are digitized and then integrated according to apparent object distance so that the sum of the true echo signals returned from the material surface is substantially greater than the sum of random noise signals for each transmitted pulse. After each eight-pulse long-range sequence, apparatus electronics automatically return to the short-range measurem…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.