Related Experiment Video
Updated: Mar 5, 2026

Calibration of Vector Network Analyzer for Measurements in Radio Frequency Propagation Channels
Published on: June 2, 2020
A Fast Measuring Method for the Inner Diameter of Coaxial Holes
Lei Wang1, Fangyun Yang2, Luhua Fu3
1State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China. wanglei2014@tju.edu.cn.
Abstract:
A new method for fast diameter measurement of coaxial holes is studied. The paper describes a multi-layer measuring rod that installs a single laser displacement sensor (LDS) on each layer. This method is easy to implement by rotating the measuring rod, and immune from detecting the measuring rod's rotation angles, so all diameters of coaxial holes can be calculated by sensors' values. While revolving, the changing angles of each sensor's laser beams are approximately equal in the rod's radial direction so that the over-determined nonlinear equations of multi-layer holes for fitting circles can be established. The mathematical model of the measuring rod is established, all parameters that affect the accuracy of measurement are analyzed and simulated. In the experiment, the validity of the method is verified, the inner diameter measuring precision of 28 μm is achieved by 20 μm linearity LDS. The measuring rod has advantages of convenient operation and easy manufacture, according to the actual diameters of coaxial holes, and also the varying number of holes, LDS's mounting location can be adjusted for different parts. It is convenient for rapid diameter measurement in industrial use.
Related Concept Videos
Thin-Walled Hollow Shafts
Energy Stored In A Coaxial Cable
In the simplest form, a coaxial cable can be represented by two long hollow concentric cylinders in which the current flows in opposite directions. The magnetic field inside and outside the coaxial cable is determined by using Ampère's law. The magnetic field inside...
Distance Measurements by Taping
Pipe Flowrate Measurement
The orifice meter is a simple,...
Electronic Distance Measuring Instruments
Transmission Shafts: Problem Solving
Next, use bending moment diagrams for the shaft to...

