Coating responsive material condition monitoring system
US5539670A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1994 |
| Grant date | Jul 23, 1996 |
| Priority date | — |
| Expiry date | Mar 10, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/96075
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A multiple set point material condition monitoring system is responsive both to the level of material with respect to a sensor and the extent of material coating which has accumulated on the sensor. The system provides an output when a predetermined coating thickness has been exceeded, so that the sensor may be cleaned before the coating can accumulate to the extent where a false level output is generated. The systems include three electrode guarded sensors, a bridge comparing the sensor output with a reference, and a bridge reference which is automatically and repeatedly caused to assume a sequence of values corresponding to material condition set points, one of which causes an output when a predetermined coating thickness has occurred and another of which generates a level output. In one embodiment, separate outputs are provided corresponding to each set point. In another embodiment, a single tri-state output is responsive to both set points.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.