Are sound detectors and sound levelmeters identical?
To put it simply, noise detectors include sound level meters, but the concept is broader and also includes individual sound exposure meters.
The essence of sound is fluctuation, an elastic wave. When the sound source vibrates, it causes the vibration of 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 a longitudinal wave. Waves in the air are called density waves. Sound waves can propagate in 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, any sound that interferes with people's rest, study and work, that is, unnecessary sound, is collectively called noise.
Noise pollution is a kind of physical pollution.
With the further development of urbanization, industrialization and transportation, as well as the increase in population density, noise pollution has attracted increasing attention from people, and the proportion of complaints among many environmental problems has been increasing year by year. Therefore, noise pollution has become an important part of environmental monitoring.
Introduction to the composition and principles of sound level meters
The sound level meter is the most basic instrument in noise measurement. Sound level meters generally consist of condenser microphones, preamplifiers, attenuators, amplifiers, frequency weighting 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 weighting network, weights the frequency of 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 (or external voltage detector). Level recorder), giving the value of the noise level on the indicator head.
