Comparison of the Thermal Conductivity Results of 10 Common Liquids with the Use of Different Devices

Abstract

In the literature there are several methods and instruments to measure the thermal conductivity of liquids. Most of the devices are promising an uncertainty less than 5% and reproducibility better than 2% but large scatter between the measured and the reference values with a lack of reproducibility can be observed for some of them. During this work new thermal conductivity measurements of 10 fluids measured using several commercial methods are presented. All the measured liquids are reference and/or potential reference liquids used from laboratories and industry to validate or usually calibrate their instruments. The methods used to employ measurements during this work was the Transient Line-Source, the Transient Plane Source and the Transient Hot-Wire. All the measurements made in our laboratory from 10 to 40oC at atmospheric pressure and the results compared according to their measured thermal conductivity and literature viscosity. A very interesting observation is that devices used in lots of laboratories for fast liquid thermal conductivity measurements show deviations from 60 to 500% for a reference liquid in the same temperature.