THE BOUNDARY INDUCED ERROR ON THE MEASUREMENT OF THERMAL-CONDUCTIVITYBY TRANSIENT HOT-WIRE METHOD

An analysis of the dimension influence on the mesurement accuracy of t hermal conductivities by transient hot wire/probe method is made. The radial and axial effects are discussed separately under the suppositio n of constant boundary temperatures. The results show that the radial and axial lengths of the measured sample, the radius ratio and heat ca pacity ratio of sample to hot wire/probe, as well as the length to dia meter ratio of the hot wire/probe are important parameters in error an alysis. Former analysis underestimated the boundary effects. New crite ria for error analysis are established.