pPropei Quality Measurement. Sound level meters measure sound pressure level and are commonly used in noise pollution studies for the quantification of almost any noise, but especially for industrial, environmental and aircraft noise. O 4 Digit LCD display. O Max, Min Function. O Accuracy ±1.5dB. O AC/DC Signal output. O Fast & slow dynamic characteristic models. O Level Range from 30 ~ 130dB. O Resolution 0.1dB update Cycle 0.5s. 3 1/2 digits LCD display with maximum O Auto Ranguing , Auto Power Off, Data hold, Max/Min Sound Level meter calibrator By many regulations, sound level meters need to verify their accuracy before and after measurements. Our sound calibrator series are designed to fulfill this customer needs. These calibrators provide different sound level at different frequencies to fit different regulations and they are perfect for periodical check on their sound level meters. 6 Fits 1 inch and 1 /2 inch Microphones.