Het principe van meten geluid met een niveau meter (geluid meter)
The frequency weighting network in the sound level meter includes A B. C Three standard weighting networks. The A network simulates the response of the human ear to a 40 square meter pure tone in the equivalent response curve, and its curve shape is opposite to the 340 square meter equivalent response curve, resulting in significant attenuation in the middle and low frequency bands of the electrical signal. The B network simulates the response of the human ear to 70 square pure tones, causing a certain attenuation in the low frequency range of electrical signals. The C network simulates the response of the human ear to 100 square meters of pure tones, with an almost flat response throughout the entire audio frequency range. The sound pressure level measured by the sound level meter through a frequency weighting network is called the sound level, and depending on the weighting network used, it is called the A sound level B and C sound levels, expressed in dB (A) DB (B) and dB (C).
Bij aanwezig, het geluid niveau meters gebruikt voor meten ruis kan worden in vier typen gebaseerd op gevoeligheid:
(1) Langzaam. De tijd constante van de meter kop is 1000 ms, die is algemeen gebruikt om te meten steady-state ruis, en de gemeten waarde is de effectieve waarde.
(2) Snel. De tijd constante van de meter header is 125ms, welke is algemeen gebruikt om onstabiel geluid met grote fluctuaties en transport geluid. Snel versnelling benadert de mens oor's reactie op geluid.
(3) Puls of puls vasthouden. De stijging tijd van het horloge naald is 35ms, welke is gebruikt om puls puls geluid met een langer duur, zodanig als ponsen machines, pers hamers, etc. De gemeten waarde is de maximale effectieve waarde.
(4) Piek onderhoud. De stijging tijd van het horloge naald is minder dan 20ms. Het wordt gebruikt om puls puls geluiden met een korte duur, zodanig als kanonnen, kanonnen, en explosies. De gemeten waarde is de piek waarde, die is de maximale waarde.
The sound level meter can be connected to external filters and recorders for spectral analysis of noise. The domestically produced ND2 precision sound level meter is equipped with an octave range filter, which is easy to carry to the field and perform spectral analysis. Sound level meters can be divided into precision sound level meters and ordinary sound level meters based on accuracy. The measurement error of a precision sound level meter is about 1dB, while that of a regular sound level meter is about 3dB. Sound level meters can be divided into two categories according to their purpose: one is used to measure steady-state noise, and the other is used to measure unstable noise and pulse noise. An integral sound level meter is used to measure the equivalent sound level of unstable noise over a period of time. A noise dosimeter is also an integral sound level meter, mainly used to measure noise exposure levels. Pulse sound level meter is used to measure pulse noise, which conforms to the response of the human ear to pulse sound and the average time of the human ear's response to pulse sound.
