... , anemometer, sound level meter, noise meter, vibration meter, ultrasonic thickness gauge, film/coating thickness gauge, digital hygrothermograph, high voltage megohmmeter, ground resistance tester, electric ... )mmresolution0.1mmsound velocity range1000~9999m/sworking frequency5MHztubing measuring lower limitΦ20*3mm(steel)auto null point calibration, system error correctionlinear auto ...