Study On Transient Plane Source(TPS) Measurement Technologies With Small-sized Probes

Transient Plane Source(TPS)method is an important branch of the transient methods for measuring thermal conductivity.It has become a focus in related research fields since it was proposed by Gustafsson in 1991.TPS probes are the core of TPS method.And it is of great significance to study the measurement technology of the probe.At present,the measurement theory of standard-sized probe(with a radius of not less than 6.4 mm)recommended by ISO standards has become very mature,and it has high accuracy for standard-sized samples in a wide range.However,in practical engineering applications,the measurement requirements for small-sized samples,such as lateral dimensions smaller than 25.6mm and thickness smaller than 6.4mm are also obvious.Since the small-sized probe provides a feasible scheme for this measuring small samples,it is necessary to study TPS measurement technologies with small-sized probe.Based on the above description,this thesis aims to study TPS measurement technologies with small-sized probes.Including the measurement principle,error sources,software algorithms and electronic system.The main work of this thesis is as follows.1.Several kinds of transient measurement methods for thermal conductivity were described.The basic structure and research status of TPS probe were introduced.And the research purpose and contents of this thesis were proposed.2.According to the definition of heat conduction and the basic theory of solid heat conduction,the calculation formula of the thermal conductivity of the material measured by TPS method was deduced,and the time function in the formula was simplified.3.The error sources in the measurement process with small-sized probes were analyzed,including the heat loss of probe lead,the heat loss of probe capacity,the heat loss of contact thermal resistance and the power loss.Three different small-sized probes were designed.The repeatability and accuracy of the measurement results of the small-sized TPS probe are evaluated by the comparative experiments,and the errors in the measurement results are corrected.4.It was found that there were still many bugs with the current version of TPS test software package.Therefore,the upgrading scheme of the TPS test software was described in accordance with the existing problems.5.In order to upgrade the current electronics of the TPS instrument,a new generation of TPS electronic system was proposed by using ADuCM360 as the core processor.The hardware modules of the electronic system were described in detail,and the corresponding software programs were designed.