Abstract: A method and apparatus for measuring and determining certain parameters of an overclad tube measures the OD and the wall thickness of the tube at a plurality of longitudinal points and a plurality of angles at each point or longitudinal position. A laser device measures the OD and an ultrasonic transducer measures the wall thickness. The inside diameter of the tube at each point is determined by subtracting the wall thickness from the measured outside diameter. From the data then obtained, the straight through internal clearance of the tube is calculated by determining a plurality of bow vectors which represent the deviations of the tube inner diameter from a least squares fit.

Abstract: A dehumidifier includes a humidistat switch to provide power to the compressor and fan when the ambient humidity exceeds a given level. The power to the compressor is also controlled by a thermostat switch and a timer. When the dehumidifier is operating in an environment that is below a given temperature, the compressor is periodically turned off for a short interval to melt any ice that has formed on the compressor coils.