Round-Robin Test for Specific Heat Capacity Measurement of Solid Materials by Differential Scanning Calorimeter

摘要

Differential Scanning Calorimeter (DSC) is a useful instrument to measure specific heat capacity of materials. However, the investigation for reliability of the measurement is insufficient, and it's necessary to estimate the uncertainty of the measurement and report on a round-robin test (RRT) for improvement of the measurement performance. In Japan, the RRT for a specific heat capacity measurement by DSC was started by the twelve local public research institutes and AIST. We measured the specific heat capacity of four kinds of material: black ceramics, stainless steel, machinable glass ceramic (MACOR®) and acrylic resin in the temperature range from 300 to 600 K. The size of the specimens was from 3 to 5 mm in diameter, which was suitable for a crucible in each DSC, and the thickness was two kinds, 1mm and 0.3mm. Furthermore, the uncertainty of the measurement for the four kinds of material was estimated by a power-compensated DSC in AIST. The relative expanded uncertainty (k = 2) was determined to be from 1.9 to 3.5 % in the temperature region. There is another convenient way to be possible to measure specific heat capacity of materials. That's the flash method which is well-known as the way to measure thermal diffusivity. We also started the RRT for specific heat capacity measurement by the flash method using four kinds of the same material concurrently. We report the results of the two kinds of RRT and the uncertainty evaluation for the specific heat capacity measurement by the DSC in detail.