The presented study examines the temperature and pressure-dependent variations in the density of the geothermal water known as “Palchyg-oba,” located in the Khachmaz district of Azerbaijan. The experiments were conducted using a high-pressure, high-temperature DMA HPM vibrating densimeter within the temperature range of T = (278.15¸373.15) K and the pressure interval of p = (0.1¸40) MPa.

The measuring unit of the device primarily comprises a magnetic measurement system, a DMA HPM Density Meter chamber equipped with a Hastelloy C-276 vibrating tube, an interferometer, and the high-pressure, high-temperature mPDS2000V3 control system (Anton Paar, Austria).

The obtained results are presented in graphical form. The DMA HPM Density Meter registers the oscillation period and temperature, transmitting these data to the IBM PC–based computing system, where the parameters can be monitored continuously. Simultaneously, the signals from the P-10 pressure gauge are transferred to the mPDS2000V3 control system and subsequently forwarded to the IBM PC computing unit. During the experiments, the temperature in the measuring cell was maintained with an accuracy of 0.01 K using an F32-ME thermostat (Julabo, Germany). Temperature measurements were performed using calibrated Pt100 platinum resistance thermometers (ITS-90) with an uncertainty of ±3 mK.