Preventive approach to determine sensor importance and maintenance requirements

Accurate sensors are the prerequisite for any building control and management operation to succeed. However, due to the lack of awareness of the importance, sensors are often out of calibration. This paper proposes a preventive approach to determine sensor maintenance requirements, which aims to explicitly quantify the importance of sensors and determine a proper calibration frequency for sensors with high importance. The approach takes account of the sensor bias growth mechanism and relates the sensor importance to a user-defined building performance index. The sensor importance is evaluated under a stochastic framework, which essentially is the way in which sensor bias grows. The calibration frequency is identified using a polynomial function which describes the degradation rate of the building performance index. The proposed approach is applied to a building located in Hong Kong. Results show that the proposed approach can effectively identify important sensors and their calibration frequency.