Novel devices and methods for in-situ testing of thermocouple drift
The aim of this work package is to develop, manufacture and test novel devices and methods that will enable the stakeholders and NMIs to monitor the drift of their thermocouples in-situ.
Thermocouples are the most commonly used type of thermometers for measuring temperature in industry. When the thermocouple tip is exposed to a given temperature, a particular voltage is generated between its leads. However, the voltage generated in a thermocouple at a particular temperature changes over time and this phenomenon is called drift. It is basically a departure of the voltage–temperature relationship from the one determined during the previous calibration, or a rapid excursion from the manufacturer’s tolerances. The rate of drift is influenced by many factors. Generally, it becomes more pronounced at higher temperatures, and therefore it is essentially impossible to predict. For industrial users drift causes many problems, such as higher energy costs, loss of time due to process disruption (to replace or recalibrate the failed thermocouples) which usually involves shutting down the processes and waste of product when measuring errors become too large. Although drift is usually anticipated at high temperatures (above 1100 °C), it can also be observed at temperatures as low as 150 °C. For the reasons mentioned, it is essential to develop new devices and methods for drift estimation that do not require thermocouple removal from the process setup. The work on the proposed topic will enable the participating NMIs to establish new networks with industrial stakeholders, as well as to share expertise among themselves through collaboration in this work package. In general, the knowledge gathered in this work package will help the partners from emerging countries to further develop their capabilities in designing and building new measurement equipment.