Measurement of thermal conductivity with the needle probe

The thermal conductivity of a range of materials has been measured by a transient needle probe technique. These include graphite, Perspex, AFS testing sand, and silica microspheres. Particular attention is paid to measurement on powders, for which packing density is important. This work forms part of an NPL project to validate transient contact-probe methods (needle probe and transient plane source) for measurement of the thermal conductivity of soft solids such as foods, powders, slurries, and biological materials.