THERMAL CONDUCTIVITY MEASURING DEVICE Russian patent published in 2024 - IPC G01N25/20 G01N25/18 

FIELD: measuring technology.

SUBSTANCE: device consists of 2 measuring cells made of a homogeneous material, placed above and below the heater, in one of the cells (upper) a sample material of thermal conductivity is placed, and the substance under study is completely located in the cavity of the lower cell, its plates with a thickness sufficient to ensure rigidity and the supply of thermocouples, their side walls are extremely thin and fix the gap between the measuring plates, and the plates that have channels opening onto the working surface of the cells, the centring and guiding guard ring from the heater, onto which the hot plates of both cells are placed. The main advantage of the relative method of measuring thermal conductivity in comparison with the absolute method is: simplicity of device design; reduction of measurement time; the ability to study a wide range of substances, study thermal conductivity of stratified systems in porous media, study thermal conductivity of substances located in the region of second-order phase transitions and critical points of solutions. This became possible due to the use of exemplary and reference materials of thermal conductivity in the design of the device, the use of separate cells, inside of which the test and reference samples are located. What is unique about the device is that the substance under study does not come into contact with electrical and heat measuring systems, i.e. they are isolated.

EFFECT: increase in functionality of the flat layer method, through the ability to study thermal conductivity of electrolytes, porous media saturated with both homogeneous and immiscible liquid solutions, nano-sized liquid systems: microemulsions, nanofluids, micellar solutions, magnetic fluids in the temperature range of (-100°C) - (+500°C) and at various pressures, including the region of phase transitions and the critical state of matter.

1 cl, 4 dwg