... and corrosion of pressure vessels,chemical equipment,boilers,oil storage tank Measuring range (metric/imperial): 1.2-200mm,0. ... 06-8inchOperating principle: ULTROSONICMaterials measured: any hard materials, including steel, cast iron, aluminum, red copper, brass, zinc, quartz ... and other materials Sound velocity: 500-9000m/sLower limit steel pipes: 15x2.0mm, 20x3.0mm determined by the ...