Tag: sound level meter

The sound level meter measurement is to convert the vibration wave signal of the metal diaphragm of the microphone (microphone head) at the front of the sound level meter into an electrical signal through the vibration wave caused by the sound signal (sound wave), and then pass through the special weighting network and circuit. After the operational amplification, the noise decibel value is displayed by digital or meter.

Multi-cell dry batteries are the most used in sound level meters, but batteries have their service life. Sometimes when the battery voltage is insufficient, the measured data will be inaccurate. This requires timely replacement of batteries when they are used to a certain extent. Usually, the sound level meter will set the indicator to check the battery status. Just press the battery check button, and the voltage of the battery can be displayed at a glance.

With the development of electronic technology, especially large-scale integrated circuit and computer technology, frequency weighting, detector and filter circuit in sound level meter are all realized by digital signal processing technology instead of analog circuit. This not only makes the circuit simpler and wider dynamic range, but also greatly improves the function and stability, especially for real-time spectrum analysis. A sound level meter is an instrument that measures the sound pressure level and sound level according to a certain frequency weighting and time weighting. It is the most commonly used instrument in acoustic measurement, which can approximate the noise level of industrial noise, traffic noise, environmental noise and living noise according to the characteristics of human hearing. It can be applied to the measurement of environmental noise, mechanical and electrical product noise, traffic noise, architectural acoustics and electro-acoustics.

Sound level meter is the most basic instrument in noise measurement. The sound level meter is generally composed of a condenser microphone, a preamplifier, an attenuator, an amplifier, a frequency weighting network, and an RMS indicator. The working principle of the sound level meter is: the microphone converts the sound into an electrical signal, and then the preamplifier transforms the impedance to match the microphone and the attenuator. The amplifier adds the output signal to the weighting network, performs frequency weighting on the signal (or external filter), and then amplifies the signal to a certain amplitude through the attenuator and amplifier, and sends it to the rms detector (or external power supply). flat recorder), the value of the noise sound level is given on the indicator head.

A sound level meter is a basic noise measuring instrument, which is an electronic instrument. But it is different from objective electronic instruments such as voltmeters. When converting an acoustic signal into an electrical signal, it can simulate the time characteristic of the human ear's response speed to the sound wave; the frequency characteristic with different sensitivity to high and low frequencies and the intensity characteristic of changing the frequency characteristic at different loudness. A sound level meter is a subjective electronic instrument.