Influence of the Earth’s magnetic field on the diagnosis of steel wire rope by passive magnetic methods

Passive techniques, which do not require magnetization of the tested object with a strong external field, are becoming increasingly popular. This article investigates the influence of the Earth's magnetic field on the diagnostic result. A detailed analysis of the steel wire rope test results in a polyurethane cover set in different directions - both geographic and magnetic - was performed. The rope was tested for two cases: in the delivered condition and with damages. The authors analyzed three different magnetic positions for each subject. Researchers analyzed the collected values in terms of the error obtained while indicating which position the results are the most promising. The authors used for the study the optically pumped magnetometer with a laser pumped caesium module.