One eye-opening opinion of Dewey was in regard to the mechanical measurement of wall thickness. In his opinion, current favorite devices are inaccurate because the internal arm of the device is affected by gravity deflection. He relies on an electronic device that emits some sort of signal (sonic? xray? radio? ) through the metal and the return signal somehow triggers an electronic readout. The device is more expensive than the purely mechanical devices. The device is used in industrial applications. Gil
Gil, I've heard more than a couple people opine on the inherent inaccuracy of mechanical BWT gauges.
