A multi-sensor based temperature measuring system with self-diagnosis

Abstract

A new multi-sensor based temperature measuring system with self-diagnosis is developed to replace a conventional system that uses only a single sensor. Controlled by a 16-bit microprocessor, each sensor output from the sensor array is compared with a randomly selected quantised reference voltage at a voltage comparator and the result is a binary "one" or "zero". The number of "ones" and "zeroes" is counted and the temperature can be estimated using statistical estimation and successive approximation. A software diagnostic algorithm was developed to detect and isolate the faulty sensors that may be present in the sensor array and to recalibrate the system. Experimental results show that temperature measurements obtained are accurate with acceptable variances. With the self-diagnostic algorithm, the accuracy of the system in the presence faulty sensors is significantly improved and a more robust measuring system is produced.