Reliability analysis of an integrated and multifunctional vibration signal measuring instrument for rotary machine

The technology based on characteristics analysis of vibration signal is the most widely used method in the process of rotary machine fault diagnosis. In recent years, with the development of fault diagnosis and computer technologies, the vibration measuring and analysis instruments are being developed quite rapidly because of their advantages such as highly integrated, multi-function, strong performance, and acceptable price. Due to a variety of uncontrolled or unexpected reasons, such as manufacturing error, installation fault, and operation mistake, the reliability of such instruments has become an important issue because it seriously affect their function and measuring results. In this paper, an integrated and multifunctional vibration signal measuring instrument is studied. The basic principles and structure of measuring instrument are presented. The possible failures are analyzed by using the method of fault tree analysis (FTA) according to the characteristics of the instrument's structure and function. The reliabilities of two different measuring circuit configurations are calculated, and analyzed comparatively with respect to cost. The result of this study will be useful during design and maintenance of such instruments.