METHOD FOR MEASURING INTERNAL DIAMETER OF METAL PIPE Russian patent published in 2018 - IPC G01B15/02 G01B7/13 

FIELD: measuring equipment.

SUBSTANCE: invention relates to measuring technology and can be used for contactless measurement of the inner diameter of metal pipes as finished products and in their manufacture, including in their production, for example, by the method of centrifugal casting in metallurgical, machine-building enterprises. Essence of the claimed technical solution lies in the fact that in the proposed method for measuring the inner diameter of a metal pipe, in which a metal rod is placed coaxially inside the tube, electromagnetic waves are excited in the measuring section of the tube in the coaxial waveguide that is being formed, excitation of electromagnetic waves is carried out at a fixed frequency at one of the ends of the measuring section, and the reception of electromagnetic waves propagating along it – at the other end of it, frequency of the excited electromagnetic waves is chosen to be less than the critical frequency of excitation of electromagnetic waves of one of the higher types in the coaxial waveguide to be formed, and the amplitude of the received electromagnetic waves of this higher type is measured, which is used to determine the inner diameter of the metal tube. Frequency of the excited electromagnetic waves can be chosen to be less than the critical frequency of excitation of electromagnetic waves of the H₁₁ type in the formed coaxial waveguide.

EFFECT: technical result of the invention is the expansion of the functionality of the measurement method.

1 cl, 2 dwg