... , sound level meter, noise meter, vibration meter, ultrasonic thickness gauge, film/coating thickness gauge, digital hygrothermograph, high voltage megohmmeter, ground resistance tester, electric leakage switch tester,gas ... , 50~100, 60~110, 80~130frequency weightingA(simulative ear)& C(noise of machine itself)time characteristicsfast/low reaction ratesampling frequencytwice/smicrophone1 ...