Is there a big difference between a noise detector and a sound level meter?
The essence of sound is fluctuation, elastic wave. When the sound source vibrates, it causes the vibration of the nearby air particles. Depending on the inertia and elastic properties of the air, the vibration of the air particles spreads around in the form of waves, forming sound waves. The direction of particle vibration is parallel to the direction of wave propagation, which is called longitudinal wave. Waves in air are called density waves. Sound waves can travel through gases, liquids, and solids.
Sound pressure: the difference between the pressure and the static pressure in the medium when there are sound waves. The unit is Pa.
Noise: From a physiological point of view, all sounds that interfere with people's rest, study and work, that is, unwanted sounds, are collectively referred to as noise.
Noise pollution is a kind of physical pollution.
With the further development of urbanization, industrialization and transportation, and the increase of population density, people pay more and more attention to noise pollution, and the proportion of complaints among many environmental problems is increasing year by year. Therefore, noise pollution has become an important part of environmental monitoring.
Noise Meter - How to Use
1. "Slow". The time constant of the meter head is 1000ms, 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 hands is less than 20ms. It is used to measure short-duration impulsive sounds, such as guns, cannons and explosions, and the measured value is the peak value. That is the maximum value. Range finder, altimeter, laser liner, flowmeter, GPS thickness gauge, leveler, flat panel, waveform recorder, test fixture, voltage and current recorder, data recorder, graphic recorder, and flow totalizer.
