Noise meter for the measurement of acoustic and environmental noise
In order to compare the measurement results of sound level meters produced in various countries around the world, the International Electrotechnical Commission (IEC) has developed relevant standards for sound level meters and recommended their adoption by countries. In May 1979, the IEC651 "Sound Level Meter" standard was passed in Stockholm, and China's national standard for sound level meters is GB3785-83 "Electrical and Sound Performance and Testing Methods for Sound Level Meters". In 1984, IEC passed the international standard IEC804 "Integral Average Sound Level Meter", and China promulgated GB/T17181-1997 "Integral Average Sound Level Meter" in 1997. They are consistent with the main requirements of IEC standards. In 2002, the International Electrotechnical Commission (IEC) released the new international standard IEC61672-2002 "Sound Level Meters". This standard replaces the original IEC651-1979 "Sound Level Meter" and IEC804-1983 "Integral Average Sound Level Meter". China has formulated the JJG188-2002 "Sound Level Meter" verification regulation based on this standard. According to the new standards, sound level meters can be classified into general sound level meters, integral sound level meters, spectral sound level meters, etc., and can be classified into level 1 and level 2 according to accuracy. The various performance indicators of the two levels of sound level meters have the same central value, only the allowable error is different, and as the level number increases, the allowable error is relaxed. According to volume, it can also be divided into desktop, portable, and pocket sound level meters. According to its indication method, it can be divided into analog indication and digital indication sound level meters.
