INCREASE OF METHODICAL ACCURACY IN THE PULSE METHOD "HOT WIRE" AT MEASUREMENTS IN THE FIELD OF LOW TEMPERATURES
conference contributionposted on 05.05.2021, 18:00 by Dmitry Simankov
V International Student Scientific Conference.
Student Scientific Forum - 2013.
Pulsed hot filament methods have long been known and well studied. This is due to the fact that these methods have advantages over stationary methods: short preparation time for the experiment, short time for the experiment, small volume of the measuring cell, and others. Standards for this method were published in the USA (ASTM C1113 / C1113M - 09), England (BS EN 993-15: 2005, BS EN 993-14: 2008). In all these methods and works in which the "hot wire" method was applied, the properties of substances and materials from room to high temperatures are often studied. In works that study the critical parameters of liquids / gases (mixtures), no attention is paid to the dependence of the resistance of the used sensor (thermistor, usually made of platinum). However, with the exploration of outer space, where the cold reigns about 4 ° K, and industrial installations operating at low temperatures, there is a need to study the thermophysical properties (TPP) of substances and materials at low temperatures. One of the methods suitable for studying TPS at low temperatures is the "hot filament" method in its various versions. Accounting for the nonlinear change in resistance of a thermoresistive measuring sensor at cryogenic temperatures is shown in this work. Prior to this, the literature did not describe the application of these dependencies in relation to the "hot thread" method.