What is a sound level meter (sound level meter)?
There are three kinds of weighting networks: A, B and C. A-weighted sound level simulates the frequency characteristics of low intensity noise below 55dB, B-weighted sound level simulates the frequency characteristics of medium intensity noise from 55dB to 85dB, and 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 attenuation is more, B is the second, C is the least. A-weighted sound level because of its characteristic curve is close to the auditory characteristics of the human ear, so it is the world's noise measurements in the most widely used one, B, C has been gradually not used.
Definition:
Noise meter Also known as (noise meter, sound level meter) is the noise measurement in the * basic instruments. A sound level meter is generally composed of a condenser microphone, a preamplifier, an attenuator, an amplifier, a frequency meter network, and an RMS indicating meter head. The working principle of a sound level meter is: the microphone converts the sound into an electrical signal, and then the preamplifier transforms the impedance so that the microphone matches the attenuator. Amplifier will be the output signal added to the network, the signal frequency meter (or external filter), and then by the attenuator and amplifier to amplify the signal to a certain amplitude, sent to the RMS detector.
Classification:
1, from the measurement object, can be divided into environmental noise (sound field) characteristics of the measurement and the measurement of sound source characteristics.
2、From the time characteristics of the sound source or sound field, it can be divided into steady state noise measurement and non-steady state noise measurement. The non-stationary noise can be divided into periodic change noise, irregular change noise and impulse sound.
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.
4、From the precision of measurement requirements, it can be divided into precision measurement, engineering measurement and noise census.
