Integrated threshold arming method and apparatus
US4538469A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1983 |
| Grant date | Sep 3, 1985 |
| Priority date | — |
| Expiry date | Jul 29, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/02836
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An intervalometer for determining the arrival time of a bandwidth limited energy pulse employs an integrated threshold arming apparatus and method for conditioning an event recognition circuit. The event recognition circuit, which is typically a zero crossing detector, responds to the conditioning signal for detecting a predetermined event after occurrence of said conditioning signal. The integrated threshold arming circuit employs a signal integration circuit responsive preferably to a rectified signal input, and comparison means for determining when the integrated value crosses a predetermined threshold. A dual threshold implementation can also be employed to further discriminate against false noise signals. The apparatus and method are preferably employed in connection with volumetric flow measurements of turbulent and time-varying fluids by ultrasonic pulse interrogation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.