Constructive Principles of Autodyne Sensors for Internal Sizes Measuring in Metallic Products

A description is given of new principles for constructing autodyne sensors intended for non-contact measurement of deviations from the nominal value of the internal dimensions of metal products using millimeter-wave radiation. The proposed sensors are distinguished by the simplicity of the design of the measuring head and low cost. They use a single, but multifunctional device, a microwave autodyne, as a transmitter of probe radiation and a receiver of radiation reflected from the inner surface of the product. Sensors that implement the proposed construction principles can be used in the machinebuilding, pipe-rolling and chemical industries to control the inner diameter of pipes during their production, as well as ovality and wear during operation of pipelines. Experimental data were obtained on the Ka-band Gunn-diode autodyne sensor.