Development of a non-invasive thermometric system for fluids in pipes

In this paper a non-invasive thermometric system for the measurement of the temperature of fluids in pipes based on the dual heat flux method is presented. The proposed solution is a possible alternative to the employment of thermowells in industrial applications. The proposed sensing system, is based on the dual heat flux method, a technique used in biomedical field. The applicability of such a measurement system in the field of interest is studied taking into account its component performance and how they influence the overall system behavior. A prototype system exploiting RTD sensors with measurement accuracy lower than 1°C has been designed, obtaining performances comparable to the thermowell ones. To reach such an accuracy a dedicated front-end electronics has been developed.