CIMA / noise meter / decibel meter / noise tester price Zhengzhou Emi instrumentation decibel meter total distribution 0371-66227105 55676313 66959363 www.5117hm.com 
 Decibel meter called sound level meter, noise meter. SL5868P 
 Decibel meter is the basic noise measurement instruments, it is an electronic instrument, but the objective is different from the electronic meter and voltmeter. In the acoustic signals into electrical signals, you can simulate the human ear to the sound speed of response time characteristics; have different sensitivity to high frequency and the frequency characteristics of loudness when changing the frequency characteristics of different strength properties. Therefore, the sound level meter is a subjective electronic devices. 
 Decibel noise measurement instrument is the most basic equipment. Decibel meter generally condenser microphone, preamplifier, attenuator, amplifier, frequency weighting network and RMS monitors and other components. Sound level meter works is: the sound from the microphone into electrical signals, impedance transformation by the pre-amplifier, microphones and attenuator to match. Amplifier output signal to the weighting network, the signal frequency weighting (or external filter), then by the attenuator and the amplifier will be amplified to a certain signal amplitude to the rms detector (or outside by electric level recorder), the display shows the noise level values. Decibel meter in the frequency weighting networks A, B, C three standard weighting networks. A network is to simulate the human ear loudness curve of 40 pure-tone response curve shape and its 340 opposite side of the equal loudness curves, so that electrical signals in a larger low frequency attenuation. B network is to simulate the human ear to pure tones of 70 square response, it makes a certain low frequency electrical signal attenuation. C network is to simulate the human ear pure tone of 100 square response, the entire audio range in a nearly flat response. Decibel frequency weighting network analyzer through the sound pressure level measured as sound level, weighted according to the network using different sound level are called A, B and C sound level sound level, the unit denoted by dB (A), dB (B) and dB (C). Zhengzhou Emi instrumentation details contact: 13017693918 DU