On-line validation of modulating sensors

The use of distributed sensor networks for process measurement and control applications is becoming more common as sensors become cheaper, and progress is made towards a standard protocol for a shared digital communication network. As the use of distributed sensor networks increases, then so does the need for reliable methods of sensor validation. The validation of sensor performance is usually achieved off-line, by removing the sensor from the process plant and testing it using a known reference. Such methods are inconvenient, and sometimes just not possible in some process applications. This paper discusses strategies which may be used to validate a sensor's performance on-line.