The Studies Of Microcomputer Differential Thermal Method And Impedance Spectroscopy's Analysis

This paper mainly explore two aspects, the first is the research and test of the differential thermal analysis machine ,and the second is the study of the electrochemical impedance spectroscopy's analysis with microcomputer.Some important components of DTA are selected or designed in this paper. We select Ni/Cr alloy resistor as element together with ceramic embedding hearth; select heat-even Cu sample holder; select Ni/Cr & Ni/Si thermoelectric couple (type K) as thermoscope with threads 0.5 mm in diameter which is installed in the middle of the holders symmetrically; select aluminum silicate fire-retardant fiber asmaterials for heat preservation; select the suitable A/D,D/A circuit board which has the function of procedure control amplification; select booster to control calefactive course. In order to obtain the reasonable operation conditions and operation curve, We have also done many theory analysis and experiment discussions. We select Al2O3 as reference; select semi-dynamic atmosphere operate machine; and the software has two kinds of construct curves for choose , there are"?T—(ttime)DTA"and"?T—T(temperature)"curves. With the advantages of right principle, simple structure, easy operation, good veracity, ideal reappearance and perfect security, it can satisfy the need of the experiment.There are two steps to solve the parameters of electrochemical impedance spectrum by curve fitting method. One is to solove the initial values, the other is to optimize the values. We design a software to solve the parameters of electrochemical impedance spectrum. The equivalent circuit can be sought of different impedance spectrum. The nonlinear least square method is applied in the procedure of optimizing the initial values. First the target function is selected, then it is transformed into linear equations. The parameters can be worked out with Gauss-Newton method. This software is developed with VB programming language. The interface is friendly and the operation for solving the parameters is very convenient. The results and the simulated plot can be displayed in the same interface.