Coriolis mass flow rate meter having a substantially increased noise immunity
US4934196A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 2, 1989 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Jun 2, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/8477
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and accompanying methods for use therein for a Coriolis mass flow rate meter which is substantially immune to noise, and more particularly, to such a meter that is substantially unaffected by noise that occurs at substantially any frequency different from a fundamental frequency at which the flow tube(s) in the meter vibrate. Specifically, the meter relies on measuring mass flow rate by determining the phase difference that occurs between real and imaginary components of the discrete fourier transform (DFT) of both the left and right velocity sensor waveforms evaluated at the fundamental frequency at which the flow tubes vibrate. The fundamental frequency is located, during an initialization operation, by providing a power spectrum, determined through use of the DFT, of one of the sensor signals and then selecting that frequency at which the magnitude of the power spectrum reaches a maximum value. In addition, the frequency at which both velocity sensor signals is sampled is readjusted in response to any change in the phase of one of the velocity sensor signals, as transformed using the DFT, in order to assure that the sampling frequency always remains substantially equal…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.