Mass flowmeter converter
US5602346A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1995 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | May 31, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/849
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A mass flowmeter converter detects a Coriolis force acting on a flow tube driven at a constant frequency as a time difference .DELTA.T between two displacement signals detected at symmetrically opposed positions. A mass flow proportional to the time difference .DELTA.T is determined. Sine-wave signals differing in phase and at a constant amplitude are detected paired detecting coils and provide input signals which are pulses having specified pulse width values equal to a leading time (T+.DELTA.T) and a lagging time (T+.DELTA.T). N number of pulses (T+.DELTA.T) and N number of pulses (T-.DELTA.T) are sampled simultaneously by respective integrators having the same time constant, and by using a reference power source a time difference of zero-crossing voltages and a time difference signal enlarged by 2N times is detected. Furthermore, a small time measurement error due to drifts of the charging-discharging circuit is compensated by alternating respective integrators.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.