Through-log density detector
US6784672B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 2002 |
| Grant date | Aug 31, 2004 |
| Priority date | — |
| Expiry date | Jun 17, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for detecting areas of differential density in logs, cants, timbers, poles or trees comprises applying a signal to one or more pairs of electrodes and measuring the magnitude and phase shift of the voltage, current or impedance at an output electrode. Electrodes may be arranged in a circumferential or opposed configuration depending on scanned product shape, and may be stationary or move freely but are preferably in direct contact with wood surface. Wire brush electrodes are used in some embodiments. Measurements are taken in both directions between an electrode pair. Multiple frequencies may be employed. Different electrode sizes may be used for different measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.