Noise meter can be classified according to different elements
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.
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.
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 accuracy of measurement requirements, it can be divided into precision measurement, engineering measurement and noise survey.
Several Classifications of Noise Meter Sensitivity
(1) "Slow". The time constant of the meter head is 1000 ms, which is generally used to measure steady-state noise, and the measured value is an effective value.
(2) "Fast". The time constant of the meter head is 125ms, which is generally used to measure unstable noise and traffic noise with large fluctuations. The fast gear is close to the human ear's response to sound.
(3) "Pulse or Pulse Hold". The rising time of the watch needle is 35ms, which is used to measure the pulse noise with a long duration, such as punch press, hammer, etc. The measured value is the maximum effective value.
(4) "Peak hold". The rise time of the watch needle is less than 20ms. It is used to measure short-duration pulse sounds, such as guns, cannons and explosions. The measured value is the peak value. That is, the maximum value. The sound level meter can be connected with an external filter and recorder to perform spectrum analysis on the noise. The domestic precision sound level meter is equipped with an octave page filter, which is easy to carry to the scene and do spectrum analysis.
