A self-validating thermocouple

• Published in: IEEE transactions on control systems technology Vol. 5; no. 2; pp. 239 - 253
• Main Authors: Yang, J.C.-Y., Clarke, D.W.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.1997; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Chemical reactors; Chemical sensors; Communication system control; Computer science; control theory; systems; Control design; Control systems; Exact sciences and technology; Fault detection; Inductors; Information retrieval. Graph; Process control; Sensor systems; Theoretical computing; Uncertainty; Validation; Uncertainty; Kalman filter; Measurement sensor; Observer; Failure detection; Controller; Fault diagnostic; Thermocouple
• ISSN: 1063-6536; 1558-0865
• DOI: 10.1109/87.556028

Traditionally the sensor has been the system component neglected by control engineers, yet it has long been recognized that accurate and reliable sensor readings are vital for good controller performance. Self-validating sensors can improve reliability through self-diagnosis and by the provision of on-line metrics (measurement accuracy and its trustworthiness). One benefit of validation is the potential to sustain satisfactory loop performance even in the presence of sensor faults. This paper describes a self-validating thermocouple that can discover several types of internal fault, including the practically important aspect of loss-of-contact with the process environment, and shows how the associated uncertainties can be calculated. The operation of the device is demonstrated through a series of experiments.