... principle: ULTROSONICMaterials measured: only 11 types of materials, including steel, cast iron, aluminum, red copper, brass, zinc, ... PVC, gray cast iron, nodular cast ironLower limit steel pipes: 15x2.0mm, 20x3.0mm determined by the ... meters, ultrasonic water meters, Gas meters, ultrasonic thickness meters, ultrasonic flaw detectors and many the same ... soon as possible. TM-8810 Ultr-thickness gauge