THB Advance/Basic – Phase change material – Thermal conductivity
A phase change material (PCM), also known as a latent heat storage (LHS) material, undergoes a state change—typically from solid to liquid and vice versa—at a specific phase change temperature.
During the process of melting or solidifying, these materials can absorb or release substantial amounts of energy, making them valuable for applications in both cooling and heating. Common uses include cold packs and heat pads, with additional applications spanning the catering industry, building sector, automotive, and clothing. Well-known examples of PCMs include water and sodium acetate, the latter being utilized in heating pads.
The provided example involves the analysis of the thermal conductivity of two hydrated salts. Both PCMs were initially in a liquid state at room temperature. The experiment involved filling the liquids into a beaker, which was then placed in a temperature-controlled liquid bath. The THB/B/Metal sensor was immersed in the sample for measurement. The recorded temperature steps included -20 °C, -10 °C, 0 °C, +10 °C, 20 °C (room temperature), and +30 °C, initiating the measurement in the solid state of the material. Three measurement points were taken at each temperature level and averaged.
The thermal conductivity of Sample A exhibited a slight increase with heating up to 0 °C, while Sample B showed a slight decrease. Both samples underwent a transition from the solid to the liquid state in the temperature range from 0 °C to 10 °C, as evidenced by a clear drop in thermal conductivity. As the temperature increased, the thermal conductivity of both samples showed a slight rise. Overall, Sample B consistently demonstrated higher thermal conductivities compared to Sample A.
Related instruments
THB – Basic, Advance, Ultimate
THB – Transient Hot Bridge – measurment of thermal conductivity and thermal diffusivity with new sensor and intuitive software.
Operating temperature: -150°C to 700°C