Intelligent instrumentation

Abstract

With the falling cost of microelectronics, intelligent instruments are increasingly used in process control. They are designed to integrate into data networks such as Fieldbus, so that remote users can access internal values and reconfigure their function. It is argued that such instruments should exploit models of the plant’s data generation to achieve optimal filtering, of their own internal behaviour as verified by self-testing, and of the user’s needs. A figure-of-merit for sensor signal processing is defined, and some fundamental results indicating the benefit of appropriate signal models are deduced. The value of validation, in which diagnosed faults affect the measurement status and its uncertainty, is emphasized. Examples of a self-validating thermocouple, a dissolved-oxygen sensor and a flow-control valve are described together with some guidelines about practical implementation.

Further Structural Intelligence for Sensors Cluster Technology in Manufacturing

“…The impact of such errors may be reduced with a dense sensors network, or, with a knowledge based system where the smart sensor incorporates expert systems for example. Self-validation becomes more important when various data from multi-sensors or multi-measurements are sent to the system [18, 24]. The objectives of this validation are to enhance safety, to provide better product quality, to reduce unscheduled shutdowns and to improve plant efficiency and availability.…”