Method of measuring moisture content of dielectric materials
US4580233A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1982 |
| Grant date | Apr 1, 1986 |
| Priority date | — |
| Expiry date | Sep 22, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/223
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention is a method for measurement of moisture in dielectric materials. It is particularly useful for lumber. In the preferred version, at least two alternating current signals whose frequencies differ by a factor of at least 10 are capacitively coupled to the material. The coupling electrodes are in bridge circuits whose unbalance is measured at each frequency. The temperature of the dielectric material is also determined. Bridge unbalance signals are separated and rectified and the voltages, as well as a temperature analog voltage, are entered into a microprocessor programmed with a suitable algorithm to calculate a temperature corrected moisture value. The method overcomes significant inaccuracies in moisture readings due to temperature dependency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.