Sound Level Meter, Digital Meter Range 30 130dB Noise Volume Measuring Instrument Tester Monitoring Decibel Autocalibrated ST9604

【Min/Max/Data Hold Function】This noise meter with maximum and minimum hold function.Data retention function.Automatic or manual power off function.Temperature measurement function. 【Scope of application】 Suitable for sound quality control in factories, offices, homes, schools and construction sites. Also suitable for measuring sound or noise in most occasions. 【Accurate and Out of Range Measurement Warning Signal】Measuring range 30 130dB, accuracy ±1.5dB, resolution 0.1dB, there will be a warning signal when the standard exceeds the standard. Red backlit alarm and audible alarm. Digits display for clear readings: The product adopts 4-digit display, which makes the reading data more clear and convenient.High sensitivity sensor, measure fast and more accurate. 【Working principle】 The microphone converts the sound into an electrical signal and the preamplifier changes the impedance so that it matches the microphone with the attenuator.The amplifier adds the output signal to the weighting network, weighs the signal frequency and then amplifies the signal to a certain amplitude through the attenuator and amplifier, and sends it to the actual value detector, the noise level is indicon.um hold indicator