Specific Heat Capacity by Differential Scanning Calorimetry ASTM E1269
ASTM E1269 is used to determine the Specific Heat Capacity of a solid and liquid sample by DSC (Differential Scanning Calorimetry). DSC is a thermal analysis instrument that measures how the physical properties of a sample change along with the temperature.
In ASTM E1269, Differential scanning calorimetric measurements provide a rapid, simple method for determining specific heat capacities of materials. Many machines get overheated which can cause system failure or damage. To prevent this, cooling systems are incorporated into the machines. A cooling system contains heat transfer fluids that absorb and dissipate large quantities of heat. To select a suitable heat transfer fluid for a cooling system, it is important to know the specific heat capacities of different materials.
It is important to know specific heat capacities for designing reactors, engines, and cooling systems. Manufacturers and engineers use specific heat capacity all the time for design, quality control, and research and development.
The temperature range at which the test is usually performed is 100 – 600 °C. An empty specimen holder and a specimen holder containing reference material, synthetic sapphire, are weighed. Both these holders are placed in the DSC test chamber and the temperature is adjusted to the initial temperature of the experiment at 20 °C/min. The temperature is maintained for at least 4 min to establish equilibrium and the thermal curve is recorded. The test specimen is then heated from the initial to the final temperature at a rate of 20 °C/min and the thermal curve is recorded. After recording the thermal curve DSC test chamber is cooled to room temperature. The sapphire standard is placed in the same empty specimen holder and its weight is recorded. The test specimen is then placed into the empty specimen holder and its weight is recorded.
Liquids specimens are sampled directly after stirring. Solid specimens may be cut or sliced with a knife or a blade. Samples are usually analyzed as received. If they are treated with heat or mechanical treatment, this treatment must be noted in the report.
DSC measures enthalpy changes in samples due to changes in their physical and chemical properties, as a function of temperature or time.