Fail-safe instrument system
US4363030A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1979 |
| Grant date | Dec 7, 1982 |
| Priority date | — |
| Expiry date | Nov 30, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/16
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In an instrument system consisting of a transmitter in one location and a receiver in another location connected by a transmission medium, fail-safe operation is obtained by restricting the output of the transmitter to well-defined levels and interpreting any substantial departure of the received signal from these well-defined levels as a failure. When a failure is detected, alarms or other equipment may be activated, including a control circuit which causes replacement of the defective transmitter or transmission medium, thereby restoring the system to service. An embodiment wherein the transmitter is an admittance-responsive transmitter in a two-wire current loop for monitoring the condition of materials is described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.