Factors to be considered in the selection of a sound level meter
Sound level meter is a kind of instrument to measure sound pressure level and sound level according to certain frequency weighting and time weighting. It is a commonly used instrument in acoustic measurements, which can be used to measure industrial noise, traffic noise, environmental noise and living noise, etc., according to the human ear hearing characteristics of the approximate determination of the noise level of the instrument.
Sound level meter can be applied to environmental noise, electromechanical product noise, traffic noise, building acoustics and electroacoustics measurements. Some sound level meters can also be used to measure vibration by replacing the receiver section. The external connection or internal setting of octave filter or 1/3-octave filter of the sound level meter can be used to analyze the spectrum of noise.
The sound level meter consists of microphone, attenuator, weighting network, amplifier, wave detection network and indicator. The foremost part of the sound level meter is the microphone, which converts acoustic energy into electrical energy and then sends it to the preamplifier of the host computer, amplifies it and sends it to the attenuator and the weighting network, and then it finally passes through the wave detector and displays the readings of the sound level on the indicator table which has a certain damping characteristic.
Selection of sound level meter should be considered factors:
Price: The first thing to consider when purchasing a sound level meter is the price range of the product. The price of a sound level meter depends on a number of factors, including features, accuracy level, number of channels, storage capacity, and so on. In general, the same indicators of the sound level meter, domestic than imported products are much cheaper.
Function: For sound level meter, the measurement function is the *important index, which not only determines the application range of the sound level meter, but also has a *great relationship with the price of the sound level meter. According to the type of signal being measured, for the steady state noise signal, the sound level meter function as long as the measurement of instantaneous sound pressure level; for the measurement of non-steady state signals, generally require the measurement of time-averaged sound level or called the equivalent sound level; for the need for spectral analysis, it is necessary to choose the noise spectrum analyzer.
Number of channels: The general sound level meter has only 1 channel to measure only 1 road sound pressure level. Sometimes you need to measure more than one sound pressure level, you need to choose more channels, for example, measuring the sound intensity level requires 2 channels, measuring the sound power level requires more channels, multi-channel sound level meter greatly extends the use of the sound level meter.
Accuracy level: Accuracy level of sound level meter: level 1 and level 2.
Spectrum analysis function: In order to perform spectrum analysis of noise, it is necessary to select the spectrum analysis function. Octave and 1/3-octave spectrum analysis are used *mostly* in acoustic measurements. Previously, spectrum analysis was realized using analog filters, but nowadays, most of them use digital technology, and real-time spectrum analysis is carried out through digital filters.
Measurement range: The measurement range of sound level meter should sometimes consider its upper limit in order to measure the high sound pressure level, such as 140dB, or even to 160dB or more; sometimes it should consider its lower limit in order to measure the low sound pressure level, such as 20dB or less; usually, the measurement range of the sound level meter is within the range of 25dB to 130dB.
