... for measuring thickness and corrosion of pressure vessels ... and machine manufacturing. Model: TM8812 TM8812C Measuring range (metric/imperial): 1.0-200mm,0.05-8inch Operating principle: ULTROSONIC Materials measured: any hard materials ... , including steel, cast iron, aluminum, red copper, brass, zinc, quartz glass, polyethylene, PVC, gray cast iron, nodular cast iron and other materials ...