Patent ID: 7609366
Filing Date: 2009-10-27
Classification: D21G,G01B,G01N

Abstract:
1. A sheet material measurement system, comprising: a THz generator including at least one laser source for emitting optical pulses, said optical pulses coupled to a THz emitter operable for emitting pulsed THz radiation at a first sample location on said sheet material while being processed by a manufacturing system; a receiver operable to receive said optical pulses and to detect reflected or transmitted THz radiation from said first sample location synchronously with said optical pulses and provide electrical detection signals; synchronizing optics operable to receive said optical pulses from said laser and provide said optical pulses to both said receiver and said THz emitter, and a controller comprising at least one processor for receiving said electrical detection signals and providing a processed electrical detection signal and an analyzer operable to determine a plurality of different sheet material properties selected from the group consisting of basis weight, moisture content, thickness, composition and fiber orientation at said first sample location from said processed electrical detection signal.