What is a sound level meter (noise meter)
There are generally three types of weighting networks: A, B, and C. The A-weighted sound level simulates the frequency characteristics of the human ear for low-intensity noise below 55dB, the B-weighted sound level simulates the frequency characteristics of moderate-intensity noise from 55dB to 85dB, and the C-weighted sound level simulates the frequency characteristics of high-intensity noise . The main difference between the three is the degree of attenuation of the low-frequency components of the noise. A attenuates the most, B takes the second place, and C is the least. The A-weighted sound level is the most widely used in noise measurement in the world because its characteristic curve is close to the hearing characteristics of the human ear, and B and C are gradually used.
definition:
Noise meter, also known as (noise meter, sound level meter) is the most basic instrument in noise measurement. A sound level meter is generally composed of a condenser microphone, a preamplifier, an attenuator, an amplifier, a frequency meter network, and an effective value indicating meter. 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 with the attenuator. The amplifier adds the output signal to the network, performs frequency weighting on the signal (or an external filter), and then amplifies the signal to a certain amplitude through the attenuator and the amplifier, and sends it to the RMS detector.
Classification:
1. From the measurement object, it can be divided into the characteristic measurement of environmental noise (sound field) and the measurement of sound source characteristics. the
2. From the time characteristics of the sound source or sound field, it can be divided into steady-state noise measurement and unsteady-state noise measurement. Non-stationary noise can be divided into periodic noise, irregular noise and pulse sound. the
3. From the frequency characteristics of the sound source or sound field, it can be divided into broadband noise, narrowband noise and noise containing prominent pure tone components. the
4. From the accuracy of measurement requirements, it can be divided into precision measurement, engineering measurement and noise survey.
