Definition of Sound Level Meter Explained
Electronic Measuring Instruments] Noise meter, also called sound level meter, is a kind of instrument to measure the sound pressure level or sound level according to certain frequency weighting and time weighting, which is the most basic and commonly used instrument in acoustic measurement. Sound level meter can be used for environmental noise, machine noise, vehicle noise and other kinds of noise measurement, can also be used for electroacoustics, building acoustics and other measurements, if the condenser microphone into an accelerometer sensor, with the integrator, you can use the sound level meter to measure vibration.
In order to make the measurement results of the sound level meter produced by various countries in the world can be compared with each other, the International Electrotechnical Commission (IEC) formulated the relevant standards of the sound level meter, and recommended that all countries adopt, in May 1979 in Stockholm adopted the IEC 651 "Sound Level Meter" standard, China's national standard on sound level meter is GB3785-83 "Sound Level Meter Electricity, Acoustic Properties and Test Methods. 1984 IEC also adopted the IEC 801 "Sound Level Meter" standard, the national standard on sound level meter is GB3785-83 "Sound Level Meter Electricity, Sound Properties and Test Methods". In 1984, IEC adopted IEC 804 "Integral Mean Sound Level Meter" international standard, and China promulgated GB/T17181-1997 "Integral Mean Sound Level Meter" in 1997. They are consistent with the main requirements of the IEC standard. 2002 International Electrotechnical Commission (IEC) issued a new international standard IEC61672-2002 "sound level meter". This standard replaces the original IEC651-1979 "sound level meter" and IEC804-1983 "integral average sound level meter". According to this standard, China has formulated JJG188-2002 "Sound Level Meter" test specification. According to the new standard, the sound level meter can be divided into general-purpose sound level meter, integral sound level meter, spectrum sound level meter, etc., according to the precision can be divided into level 1 and level 2, the two levels of sound level meter of various performance indicators have the same center value, only the allowable error is different, and with the increase of the level of the number of allowable error relaxation. According to the volume can also be divided into desktop, portable, and pocket sound level meter. According to its indication mode can be divided into analog indication and digital indication sound level meter.
Sound level meter is mainly used to measure the noise, and the classification of noise measurement mainly has the following kinds:
1. From the measurement object, it can be divided into the measurement of environmental noise ( sound field ) characteristics 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 non-steady state noise measurement. Non-stationary noise can be further divided into periodic variation noise, irregular variation noise and impulse 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 precision of measurement requirements, it can be divided into precision measurement, engineering measurement and noise census.
