Science and technological developments: article

PRECISION DIFFERENTIAL THERMOMETERS FOR STUDYING THERMAL PROCESSES BASED ON THE GEOPHYSICAL OBSERVATORY IN NORTHERN CAUCASUS
D.V. Likhodeev1
V.V. Gravirov1,2
K.V. Kislov2
1 Schmidt Institute of Physics of the Earth, RAS
2 Institute of Earthquake prediction Theory and Mathematical Geophysics, RAS
Journal: Science and technological developments
Tome: 97
Number: 1
Year: 2018
Pages: 15-24
UDK: 550.361:551.21.033
DOI: 10.21455/std2018.1-2
Keywords: temperature sensors, the Earth's thermal field, monitoring
Аnnotation: In order to study the fine structure of temperature fields in the thickness of rocks, precision narrow-band temperature sensors have been created that allow carrying out temperature measurements with sensitivity at least 0.005 °C. It is shown, that it is possible to achieve the required sensitivity by narrowing the measuring range, using platinum thermoresistors and 24-bit ADC for digital signal recording. The developed thermometer is based on the using of platinum thermistors, which have a practically linear temperature dependence of the change in internal resistance from the external temperature and excellent long-term stability of their basic characteristics. To reduce the noise level, special technics of low-frequency filtering of both output signals and all supply voltages are applied. The output differential signals of the thermometer allow it to be easily connected to the majority of modern electronic data acquisition systems. Principal ways to achieve the required measurements accuracy, calibration and installation of the necessary operating temperature range of sensors are considered. Carrying out measurements using the developed sensors will provide unique data on the structure and dynamics of the thermal field near the Elbrus volcano in the tunnel of the Geophysical Observatory in Northern Caucasus of the IPE RAS in the Baksan Gorge. This constant monitoring is a particularly very important task, in both point of view as obtaining new fundamental knowledge about the structure of magmatic structures, and as the viewpoint of assessing the volcanic hazard caused by the presence of a liquid magmatic melt in the bowels of the volcano. These data will provide new knowledge about the potential hazard of the Elbrus volcanic center. Carrying out of such researches is especially actual now in the light of actively developing tourist infrastructure both in the Baksan gorge and in the Elbrus region as a whole.