Self-validating sensors check their own health
Researchers at Oxford University are developing a technology that allows sensors to check their own performance, resulting in more accurate and efficient plant operation.
Field trials are already under way and the first Seva (self validation) products are expected to reach the market within a year. The work, at the University`s department of engineering science, is being funded by Invensys.
Announcing the development recently, Invensys chief executive Allen Yurko pointed out that "poor quality data from sensors can be a major cause of waste and inefficiency". Hailing the Seva technology as "revolutionary", he said it would cut plant downtime, improve product quality, and reduce maintenance and operating costs.
The Oxford researchers are developing a variety of Seva devices including flow meters, cavitation detectors and a thermocouple that can detect open- and short-circuit faults and loss of thermal contact with the object whose temperature it is measuring. It can also check that it has been re-installed correctly after maintenance.
Another development is a self-validating valve which harnesses the computing power of the Internet. The idea is to provide a unique Internet address for every field device, allowing users to perform remote diagnostics and to keep track of the performance of the devices from anywhere in the world.
Other projects underway at the Oxford laboratories include the development of Ethernet-based field devices designed to bridge the gap between control and corporate networks, and a control loop monitor that assesses continuously whether a loop is in tune and advises if re-tuning is necessary.
The researchers are also working with Invensys Rail Systems to produce a system that will monitor the condition of railway switching points to provide an early indication of faults before rail traffic is disrupted. In parallel with these developments, the Oxford researchers have been working with BSI to develop a standard for the terminology used in intelligent instrumentation.
The BSI`s AMT/7 committee has recently approved a document containing terms defining measurement quality parameters and device health status and this is being published as a pre-standard. The data is also being shared with the International and European standards bodies, IEC and Cenelec.
