Method and apparatus for automatic offset compensation in parameter-sensing transducer systems
US4817022A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1986 |
| Grant date | Mar 28, 1989 |
| Priority date | — |
| Expiry date | Jul 30, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L13/025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods and apparatus by which a transducer is employed to create a digital signal representing numerically the value of a changeable physical parameter. The signal from the transducer is subject to large and unpredictable amounts of offset due to either or both (i) manufacturing tolerance departures from the desired target of creating a zero output signal value when the sensed parameter is zero and (ii) changes in offset due to changes in one or more physical conditions (other than the sensed parameter) to which the transducer and its associated electrical components are subjected. A bistate device is associated with the transducer and controlled so as (a) to first apply substitutionally to the transducer a known, and preferably zero, value of the parameter--with the output signal value being stored so as to represent the then-existing offset, and then (b) to apply the changeable physical parameter to the transducer. The stored value of the transducer output signal is, in effect, subtracted from the output signal obtained in the second instance, to produce an accurate final signal numerically representing the existing actual value of the sensed parameter. A programmed microcompute…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.