The electret microphone, which is widely used in electrical appliances such as radio cassette recorders and telephones, directly affects the performance of voice transmission and recording. The sensitivity of this type of microphone can be easily tested with a multimeter.
Dial the multimeter to the R & TImes; 100 position, the two test leads are respectively connected to the two electrodes of the microphone (be careful not to be mistakenly connected to the ground electrode of the microphone), after the multimeter displays a certain reading, blow gently with the mouth to the microphone (the blowing speed is slow and Even), observe the swing amplitude of the hands while blowing air. At the moment of blowing, the greater the amplitude of the needle swing, the higher the microphone sensitivity, and the better the speech delivery and recording effects. If the swing amplitude is not large (fine movement) or does not swing at all, it means that this microphone has poor performance and should not be used.
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