Arrangement for contactless measurement of the velocity of a moving medium
US4708021A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1986 |
| Grant date | Nov 24, 1987 |
| Priority date | — |
| Expiry date | Jan 31, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P5/18
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The arrangement for contactless measurement of the velocity of a moving medium comprises two transducers which furnish electrical signals into which inhomogeneities of the moving medium enter depending on their spatial position in accordance with different spatial weighting functions. The detecting regions of the two transducers are offset with respect to each other in the direction of movement of the medium but partially overlap in such a manner that the gradient of the spatial cross correlation function for the spatial displacement zero is different from the zero vector. A correlator forms the time cross correlation function of the two signals and an evaluation circuit derives the measured value for the velocity of the moving medium from the gradient of the time cross correlation function for the time displacement zero. Alternatively, the measured value may also be derived from the first moment of the cross power density spectrum of the two signals because said moment is mathematically equivalent to the gradient of the time cross correlation function of the two signals for the time displacement zero.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.