Moisture detection circuit
US5486815A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 26, 1993 |
| Grant date | Jan 23, 1996 |
| Priority date | — |
| Expiry date | Jan 26, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/223
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A detector circuit in a moisture detector having an oscillator, a detector electrode and a common electrode for measuring the moisture content of wood and structural materials in buildings comprises a clamping diode network which couples an AC signal generated in the oscillator to a detector electrode. The clamping network clamps the AC signal to a reference voltage. The clamping network is balanced by a second clamping diode network which, together with a low pass filter, establishes the reference voltage. A low pass filter connected to the first clamping network produces an output voltage signal related to the impedance between the electrodes. To maintain the circuit's stability, the diodes in the clamping networks are thermally coupled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.