A new Peltier sensor for measuring the thermal conductivity of fluids

This paper describes a new sensor and a new method to measure the thermal conductivity of many fluids. The principal advantage of the device is self compensation against temperature brought about by an appropriate choice of the materials. Moreover, because the sensor uses both the Peltier and Seebeck effects, measurements can be carried out with accuracy according to an average temperature increase of the device lower than 5 K. Operation of the device brings about a very low Joule power (5 mW). A coherent design rationale is formulated and the various stages in the technical development of the sensor are delineated. Several cases are discussed with a view to increasing the applicability of the method. Notable applications include thermal conductivity gauges for measuring pressures in high-vacuum systems, tank gauging for liquids featuring fire hazards, and low velocity measurements occurring in natural convection mechanisms. It is expected that the versatility of the device will result in a wide number of industrial applications.