Implementation of 3Omega Method for a Wide Range Measurements of Thermal Conductivity of Liquids

Abstract

Thermal conductivity is an important thermophysical property of materials. The advancements in material sciences and manufacturing techniques have led to the development of various techniques for thermal conductivity measurements. Among these methods, the AC hot wire (3 omega) method is a prominent option due to its advantages such as insensitivity to black body radiation and minimal sample requirement. Even though this measurement method has been quite popular in thermal conductivity measurements of thin films for several decades and is gathering attention for the measurements of liquids, there are no studies where the hardware of the measurement methodology is depicted as the method is quite complicated. In this study, a custom-made 3omega setup is presented and its performance in a wide range of thermal conductivity measurements is evaluated by investigating the thermal conductivity of base fluids such as water, ethanol, methanol, ethylene glycol (EG), and mineral oil. In addition, the relative thermal conductivity of the base fluids is compared with the literature. The proposed setup shows that the maximum error rates were obtained in a range of 0.5 to 5% depending on the base fluid.