Features of Noise Meters
① It can measure the noise with complex waveform and display its root mean square value, that is, detect it according to the square law;
②Because the human ear cannot fully perceive the sound with a duration of less than 200 milliseconds, the 800 Hz signal of 200±50 milliseconds should produce the same indication as a continuous 800 Hz signal of the same amplitude; if the signal duration is shorter, the meter small indication;
③In order to simulate the situation that the human ear listens to the telephone or broadcast, there are two weighted (weighted) networks for telephone and broadcast, which can be selected according to needs. When the weighted noise is expressed in terms of level or power, it should be marked with "P" according to the network used, the phone should be marked with "ps", and the broadcast should be marked with "ps", such as dBm0p, dBm0ps, etc.;
④When it is not connected to the weighing network, it can also measure the broadband noise of 20 Hz to 20 kHz, which can be used when the telephone circuit is opened for data, telegraph and fax.
