Turgut A.Sauter C.Chirtoc M.Henry J.F.Tavman S.Tavman I.Pelzl J.2019-10-272019-10-2720081951-63551951-6355https://doi.org/10.1140/epjst/e2008-00459-7https://hdl.handle.net/11454/27464We present a new application of a hot wire sensor for simultaneous and independent measurement of thermal conductivity k and diffusivity ? of (nano)fluids, based on a hot wire thermal probe with ac excitation and 3? lock-in detection. The theoretical modeling of imaginary part of the signal yields the k value while the phase yields the ? value. Due to modulated heat flow in cylindrical geometry with a radius comparable to the thermal diffusion length, the necessary sample quantity is kept very low, typically 25µl. In the case of relative measurements, the resolution is 0.1% in k and 0.3% in ?. Measurements of water-based Aerosil 200V nanofluids indicate that ultrasound treatment is more efficient than high pressure dispersion method in enhancing their thermal parameters. © EDP Sciences/ Societé Italiana di Fisica/Springer-Verlag 2008.en10.1140/epjst/e2008-00459-7info:eu-repo/semantics/closedAccessConference Object1531349352Q2