Development of a Heat Pipe-based Hot Plate for Surface-Temperature Measurements

The development of a flat heat-pipe-based hot plate operating in the temperature range from ambient to 200 ◦C is presented here. The aim of the designwas to improve the heat-transfer performance in order to provide almost ideal thermal uniformity of surface and volume temperature profiles, thereby ensuring a minimal temperature gradient and a small effective thermal resistance. The device was investigated to evaluate its performance in view of its potential use as a calibration apparatus for surface-temperature sensors. An accurate characterization was carried out to estimate the surface-temperature stability and uniformity under different thermal conditions. Measurement results showed temperature stability within 0.03 ◦C and uniformity of the heat-pipe (HP) hot-plate surface better than 0.08 ◦C. As a result of its high thermal conductivity, a small perturbation (<0.2 ◦C) of the temperature field both on the surface and inside the device chamber, when a contact probe is applied on its surface, was obtained. The study of the HP hot plate and the performed tests suggest that such a device has potential as a calibration apparatus for surface-temperature sensors.