Remotely calibratable instrument system
US4849754A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 1988 |
| Grant date | Jul 18, 1989 |
| Priority date | — |
| Expiry date | Feb 2, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08C19/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A two-wire, admittance-responsive instrument system in which a transmitter, receiver and calibrator are connected by a two-wire transmission line is disclosed. The calibrator repetitively transmits a calibration enabling signal causing the transmitter to increment a reference admittance for comparison to a sensed admittance corresponding to a known physical condition. The calibrator monitors the bistable output signals transmitted by the transmitter in the calibration mode, which changes state when the incremented reference admittance bears a predetermined relationship to the sensed admittance. The calibrator may then transmit additional calibration enabling signals causing preload to be established for transmitter operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.