Self-zeroing pressure transmitter with automatic pressure manifold
US4655074A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1985 |
| Grant date | Apr 7, 1987 |
| Priority date | — |
| Expiry date | Aug 12, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L27/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pressure transmitter assembly comprises a pressure transducer having a pair of inputs each connected to a separate pressure line. A valve is connected in each pressure line. A pressure equalizing line is connected between the pressure lines at a point between the valves and the pressure transducer. The pressure equalization line is provided with an equalization valve. All three valves are connected to a switching circuit which is controlled by a microprocessor. The switching circuit functions to open both of the valves in the pressure lines while closing the equalizing valves so that the pressure transducer is exposed to two separate pressure and generates a signal corresponding to a difference in two separate pressures. To zero the transducer and recalibrate the transmitter, the low pressure line valve is closed while the equalizing valve is opened. This equalizes the pressure between the two pressure lines so that any signal from the transducer corresponds to a zero pressure difference value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.