Reference Adiabatic Calorimeter: Hardware Implementation and Control Algorithms

The paper describes the design and control system of a reference adiabatic calorimeter, which is part of the State Primary Standard for the unit of the specific thermal capacity of solids (GET 60-2019). The components of the equipment, as well as the control algorithms that provide the required measurement accuracy, are considered in detail. The digital control system maintains a specific temperature difference with an error of less than 0.06°C in the dynamic mode and less than 0.001°C in the static mode, allowing the calorimeter to operate in an adiabatic mode in the range of 30°C–600°C. A predictive proportional-integral-derivative controller is used for control, with the parameters generated using a mathematical model.