METHOD AND DEVICE FOR NON-CONTACT DETERMINATION OF SPECIFIC ELECTRICAL RESISTANCE OF METALS IN HIGH TEMPERATURES Russian patent published in 2019 - IPC G01N27/14 G01R27/02 

FIELD: physics.

SUBSTANCE: invention relates to physics, namely to analysis of materials by non-contact determination of specific electrical resistance of a cylindrical-shaped metal sample heated in an inductor of a high-frequency induction generator in the temperature range of 1,000–2,500 K. In the disclosed method, the measurement principle is based on the dependence on the specific electric resistance of the material of a cylindrical sample magnitude of electromotive force inductively induced on one circular turn of multi-turn coil, coaxially located in the middle of the sample placed in the electromagnetic field created by the high-frequency induction generator. Two coils of different diameter coaxially located in the middle of the sample are used, which enables to determine specific electric resistance of the sample relative to electromotive forces induced inductively on one turn of each coil. Electric resistivity found by this method enables calculating the power introduced into the sample during inductive heating, which enables to find, in particular, values of the integral degree of blackness according to the Stefan-Boltzmann law. Proposed method is realized on the basis of an installation containing a vacuum chamber with an inductor of a high-frequency generator (of the HGT7-15/440 type), in which there is a cylindrical metal sample with two ceramic coils placed coaxially with it. Electromotive forces induced in turns of coils are alternately measured with a voltmeter (type V7-27a), and then there are EMF values per one turn -ε₁=ε₁/n₁ and ε₂=ε₂/n₂. Absolute and brightness temperature of the sample are measured by an optical pyrometer (LOP-72 type). Generator frequency is displayed on its display. Objective of the proposed invention is to develop a contact-free method of determining specific electrical resistance of a sample material heated by a high-frequency induction generator. Found values of specific electric resistance allow calculating the power introduced into the sample at induction heating and thus the value of the integral degree of blackness, which provides for the complexity of the method.

EFFECT: increased accuracy and informativeness of the data.

2 cl, 1 dwg