Method and apparatus for circuit fault detection with boiler water level detection system
US6650128B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 19, 2002 |
| Grant date | Nov 18, 2003 |
| Priority date | — |
| Expiry date | Apr 28, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/244
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fault detection circuit in a boiler-water level system includes a dual-frequency signal generator which develops two AC components with no associated DC component. The two frequencies are mixed and sent through an impedance matching circuit to match the impedance of the signal generating portion of the system with the impedance of the boiler water under measurement. The impedance-matched signal is then directed to two legs, one leg directed through one of a plurality of electrode probes and then to a first filter circuit, and the other leg is directed a second set of filters. In combination, the filters pass either the higher or the lower of the two frequencies to determine an open or short condition in the level sensing circuitry, as well as a steam vs. water condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.