What is a sound level meter (noise meter)?
Name explanation:
There are generally three types of weighted networks: A, B, and C. The A-weighted sound level simulates the frequency characteristics of the human ear to low-intensity noise below 55dB, the B-weighted sound level simulates the frequency characteristics of medium-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 has the most attenuation, followed by B and C the least. 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. B and C are gradually no longer used.
definition:
Noise meter, also called (noise meter, sound level meter), is the most basic instrument in noise measurement. Sound level meters generally consist of condenser microphones, preamplifiers, attenuators, amplifiers, frequency meter networks, and effective value indicating meters. The working principle of the sound level meter is: the microphone converts the sound into an electrical signal, and then the preamplifier converts the impedance to match the microphone and the attenuator. The amplifier adds the output signal to the network, performs frequency weighting on the signal (or connects an external filter), and then amplifies the signal to a certain amplitude through the attenuator and amplifier and sends it to the effective value detector.
Classification:
1. According to the measurement objects, it can be divided into measurement of characteristics of environmental noise (sound field) and measurement of sound source characteristics.
2. Based on the time characteristics of the sound source or sound field, it can be divided into steady-state noise measurement and unsteady-state noise measurement. Unsteady noise can be divided into periodic changing noise, irregular changing noise and impulse sound.
3. Based on 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. According to the accuracy of measurement requirements, it can be divided into precision measurement, engineering measurement and noise census, etc.
