METHOD AND APPARATUS FOR EVALUATING THE DRYING PROPERTIES OF UN-DRIED WOOD

A method of evaluating un-dried lumber for its propensity to degrade, during drying couples an acoustic pulse to un-dried lumber and measures the speed of the propagating of the pulse through the lumber. Preferably, the pulse is directed transversely to the lumber's grain. The pulses may be generated by a calibrated weight striking the lumber's surface and detected at two points on the lumber by means of acoustically coupled accelerometers. A timer, triggering on similar portions of the acoustic pulse as detected at the two points provides the necessary information to deduce speed. A speed threshold is determined empirically by studying samples of the lumber type and the speed of acoustic pulses through them and drying them to determine their propensity to degrade.