Today we will break down the core working principle of the specific heat capacity detector, which is essentially based on the "calorimetry method". By accurately measuring the relationship between the heat absorbed (or released) by the material and temperature changes, combined with the material mass, the specific heat capacity is calculated according to the basic thermodynamic formula.

The core logic is clear: the definition of specific heat capacity c is the amount of heat required to increase the unit temperature per unit mass of material, that is, c=Q/(m ·Δ t). The core of the instrument is to accurately capture three key parameters: Q (heat), m (sample mass), and Δ t (temperature change).

From the perspective of the testing system, the instrument mainly includes a constant temperature heating module, an adiabatic calorimeter, a high-precision temperature sensor, and a heat metering module. When testing, first place a standard size specimen of known mass (usually in block or sheet form, ensuring uniform heating) into an adiabatic heat chamber to avoid heat loss to the outside - this is the key to ensuring testing accuracy, as adiabatic performance directly affects data accuracy.

Subsequently, the constant temperature heating module applies stable and controllable heat to the sample (optional power heating or constant heat heating mode), and the heat metering module records the total input heat Q in real time. At the same time, a high-precision temperature sensor (with an accuracy of ± 0.01 ℃) synchronously monitors the temperature change Δ t of the sample before and after heating, capturing the temperature response curve from the initial stable temperature value to the stable temperature after heating.

It should be emphasized here that the insulation design needs to achieve no lateral heat dissipation and no thermal bridge transfer. Some instruments will adopt a dual cavity comparative design, which offsets the influence of environmental temperature fluctuations through a reference cavity. Finally, the instrument automatically calculates the specific heat capacity value based on the above formula. If it is a composite material or heterogeneous material, the average value will be taken through multi-point testing to ensure the representativeness of the results.

The core of the entire principle is the precise matching of heat and temperature changes. All designs revolve around reducing heat loss and improving temperature and heat measurement accuracy, which is also the key to ensuring that test data complies with national standards such as GB/T 14604-2019.