... anemometer, sound level meter, noise meter, vibration meter, ultrasonic thickness gauge, film/coating thickness gauge, digital hygrothermograph, ... ground resistance tester, electric leakage switch tester,gas detector.2.Specifications Modal TL100measuring range1.2~220mm(steel) ... lower limitΦ20*3mm(steel)auto null point calibration, system error correctionlinear auto compensation, correct nonlinear ...