Sensors for condition monitoring: a review of technologies and applications

Purpose - This paper aims to provide details of the technology and applications of the sensors and instruments used in condition monitoring practices. Design/methodology/approach - Following an introduction to condition monitoring, this paper discusses the sensors and instruments used in the major techniques, notably vibration, acoustic emission, shock pulse monitoring, wear debris analysis and thermal methods. Applications are also discussed. Findings - Condition monitoring techniques play a vital role in reducing in-service failures and unscheduled down-time and allow the implementation of condition-based maintenance. These techniques are reliant on a range of sensors based principally on piezoelectric, electrodynamic, eddy current, inductive, magnetic and thermal technologies. Originality/value - This paper provides details of the sensors used in machinery condition monitoring and discuses their applications.