FIELD: physics, measurement technology.
SUBSTANCE: invention can be used for contactless measurement of the inner diameter of metal pipes at metallurgical and mechanical engineering enterprises, including during production thereof, for example by centrifugal casting. The invention can also be used in contactless measurement of the inner diameter and wall thickness of pipes. The disclosed device for measuring the inner diameter of a metal pipe, comprising a metal rod placed coaxially inside said pipe and consisting of three sections, the first and second of which the same diameter, and the third section, lying in between on the measuring section of the pipe, has a different diameter, wherein on said pipe section electromagnetic oscillations are excited as in an open-end cavity resonator, an electronic unit for exciting and capturing electromagnetic oscillations in the cavity resonator and measuring resonance frequency of the electromagnetic oscillations, electrically connected by a communication line and a communication element to the cavity resonator, wherein the frequency of the excited electromagnetic oscillations is selected less than the critical frequency of exciting electromagnetic waves on pipe sections with sections of the metal rod with the same diameter. On the third section, the metal rod has a diameter which is reduced compared to the diameter of the metal rod at the first and second sections.
EFFECT: invention widens the field of use.
2 cl, 2 dwg
