In-process Measuring of Capacitance Per Unit Length for Single-core Electric Wires

A E Goldshtein ,Galina Vavilova ,Sergey Mazikov

doi:10.1088/1742-6596/671/1/012062

Abstract

The paper describes technical in-process implementation of the electrical method to measure the electrical capacitance per unit length of a single core electric wire. The basic design values of the electro-capacitive measuring transducer are determined. The impact of changes in water conductivity on measurement results is analyzed. Techniques to offset from the impact of changes in water conductivity on the results of the electrical capacitance per unit length control based on indirect electrical conductivity measurement are considered. An appropriate correction of the conversion function is made.

Highlights

Capacitance per unit length for electric cable and related impedance are considered to be important parameters for a number of cable products such as communication cables, radio-frequency cables and LAN-cables [1]
Techniques to offset from the impact of changes in water conductivity on electro-capacitive measuring transducer (ECMT) conversion function
The analysis of these results shows that without offset from the impact of changes in water conductivity the relative measurement error can reach 20 %, when offsetting, the values of the capacitance per unit length calculated by formula (3) for these ranges of parameters affecting the actual values differ by not more than 2.5 %

Summary

Introduction

Capacitance per unit length for electric cable and related impedance are considered to be important parameters for a number of cable products such as communication cables, radio-frequency cables and LAN-cables [1]. The cable capacitance is tested to meet the standard requirements according to GOST 27893-88 for final quality [2] The drawback of this technique is that the cable cannot be tested along its entire length, and the quality of the product can be assessed after its manufacturing only. This drawback can be eliminated through the in-process testing of the single core cable wire at the stage of the conductive core insulation. The water provides an electrical contact between the core sheath and the tubular measuring electrode This technique is employed by the leading companies specializing in the production of inspection devices for the cable industry: Sikora, Zumbach [3,4,5,6].

Published under licence by IOP Publishing Ltd

Findings

Conclusion