T-History Tests

The T-history test method is a method that allows testing the melting temperature, subcooling degree, heat of fusion, specific heat and thermal conductivity of several phase-change materials at the same time. Phase change materials are used in energy efficient buildings today. The T-history method is effective in determining the enthalpy of fusion, specific heat, and thermal conductivity for large phase-change material samples.

Thermal conductivity is determined by measuring the heat flux and temperature differences of phase change material samples. There are many methods and tools available to measure the thermal conductivity of a fluid. One of these methods is the T-history method. To measure the thermal conductivity of a phase change material using this method, the sample is placed in a long tube whose length is at least 15 times larger than its diameter.

Therefore, heat transfer is assumed to be one-dimensional. The temperature of the sample in the tube is homogeneous and slightly higher than the phase change temperature of the sample. This sample in the tube is suddenly immersed in a cold bath whose temperature is lower than the phase change temperature. The time taken for the phase change to occur and the thermal conductivity of the solid sample are calculated by an equation.

Briefly, T-history test method is used to test large amount of phase change material samples. This method allows the simultaneous determination of the thermophysical properties of a large number of samples. Thermophysical properties are extracted from the temperature-time curves of phase-change materials and the curve is compared to the temperature-time curve of the reference material (usually pure water).

The T-history test method is a simple method to determine the heat of fusion, specific heat and thermal conductivity of phase-change materials. Compared with other methods such as traditional calorimetric methods, differential thermal analysis and differential scanning calorimetry methods, T-history method has outstanding features. For example, the test unit is simple, it can measure the heat of fusion, specific heat and thermal conductivity of various samples.

It determines the phase change process of phase change materials simultaneously and for each sample separately. This method is particularly useful for the selection of many candidate phase change materials used for engineering purposes and for the preparation of new phase change materials.

Our organization also provides T-history testing services with its trained and expert staff and advanced technological equipment, among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors.