There are currently two ways to detect abnormal sounds in bearings. One is acoustic based noise detection and the other is vibration based detection.

(1) Noise detection method: Under the muffling environment with basic noise less than 20db, the high-quality microphone is used to extract the bearing sound pressure signal at a certain distance and direction, and the abnormal acoustic component is extracted by a certain analysis method. Direct measurement of abnormal sounds.

(B), vibration detection method: is an indirect detection method of abnormal sound, but also can be divided into qualitative detection method and quantitative parameter detection method. Among them, the qualitative detection method is divided into the monitoring abnormal sound method and the observation vibration waveform method. The quantitative parameter detection method refers to the evaluation of the abnormal sound of the bearing by using the measured parameter values ​​related to the abnormal sound in the vibration signal of the tested bearing, such as the peak value of the vibration and the crest factor.

(3) Measuring instruments for measuring abnormal sound of bearings: There are many measuring instruments for measuring abnormal sound of bearings, for example: BANT-1 type bearing abnormal sound monitor of Hangzhou Bearing Test Research Center; S092 bearing vibration of Shanghai Bearing Technology Research Institute (abnormal Sound) measuring instrument; S0910-III jointly developed by Luoyang Bearing Research Institute and Dalian Bearing Instrument Factory. These bearing measuring instruments can measure the effective value of bearing vibration and can measure the peak value, crest factor and pulse number of the abnormal acoustic parameters of the bearing.