Fig. 1. A standard BGR TECH calorimeter with stirring devices for calorimetric reactions vessels

      Fig. 1 presents a typical BGR TECH calorimeter. As it is seen in Fig. 1 it can be used over the temperature range from 303 K to 673 K. It has built-in liquid and dry air coolers. Thus, with an additional external cooling thermostat and a dry air flushing the temperature range can be lowered down to at least 223 K. The calorimeter is a versatile instrument with two symmetric entries to the calorimetric detectors, upper and bottom, what permits to adapt experimental vessels to investigation of various processes with the simultaneous use of additional detectors, such as spectroscopic, pH or other, and assure an efficient stirring of the content of the vessels with a step-wise or continuous dosing of reactants. Also, the sensitivity can be easily adapted to the requirement of the processes under investigation, ranging from tenths of microwatt up to a few hundreds of miliwatts. Especially for test experiments an automatic selection of the calorimetric sensitivity and its automatic change, if needed, during the course of the experiment is also possible. Special experimental vessels containing internal bellows and a special sensitive device for the recording of the bellows displacement are offered for simultaneous measurements of isobaric heat capacity and thermal expansion of liquid systems over large temperature intervals under pressures up to 20 MPa without any controlling high pressure pump.