Method of compensating the interference DC voltages in the electrode circuit in magnetic-conductive flow measurement
US4422337A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 21, 1981 |
| Grant date | Dec 27, 1983 |
| Priority date | — |
| Expiry date | Sep 21, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/60
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An arrangement for magnetic-inductive flow measurement of an electrically conductive liquid flowing in a conduit includes a magnetic field generator which generates a periodically reversed magnetic field passing through the conduit perpendicularly to the flow direction. In the conduit two electrodes are disposed. The voltage taken from the electrodes is applied to a measuring amplifier. Connected to the output of the measuring amplifier are two sample and hold circuits which are controlled by a control circuit in such a manner that they sample the output voltage of the measuring amplifier for equal induction values of opposite sign of the magnetic field and store the sampling values until the next sampling. A subtraction circuit forms the difference of the stored sampling values. In a control loop between the output and the input of the measuring amplifier there is a storing control circuit which in predetermined compensation time intervals forms a compensation voltage value regulating the output voltage of the measuring amplifier to zero. The compensation method resides in that each compensation time interval lies within the time interval, corresponding to the switched-on magnetic…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.