Noncontact thermophysical property measurement system

Bethel Co. Ltd. (Ibaraki, Japan) develops medical, dental plastic products and measuring devices for measuring thermophysical properties. The company highlights the Thermowave Analyzer, which measures the absolute value of thermal diffusivity using periodic heating radiation thermometry. It is best suited for new material development and product inspection.

The instrument’s heating source is a semiconductor laser and the detector a radiation thermometer. Both the heating source and detector enable complete noncontact measurement. 

The Thermowave Analyzer’s boasts a dynamic measurement range from organic film to diamond, making it highly effective for measuring graphite sheets, for example. In-plane and out-of-plane direction measurement  availability also makes the instrument useful for evaluating the anisotropy of materials; in-plane measurements meet JIS7240. Measurements can also be mapped to evaluate for defects and irregularities in a sample.

As a feature of the device, there is no specification for the size of the measurement sample. The external shape of the measurement sample is free. However, the minimum sample size is a diameter of 20 mm or larger.

Bethel Co. Ltd. notes that there is a difference in sample conditions between materials with low thermal diffusivity and those with high thermal diffusivity. If the conditions can be met, the same measurement sample can be used for continuous measurement of the out-of-plane and in-plane direction.