Laboratory Simulation of the Deperm Process
Abstract
The practise of demagnetising or "deperming" ships and submarines in order to evade magnetic detection has been around since World War II. The methods used rely somewhat on empirical knowledge and little research has been done to analyse the magnetostahc processes occurring during a deperm. We have constructed a scale model of a possible magnetic treatment facility for performing deperms on small (<% m) steel samples and measuring magnetostatic quantities that relate to the deperm procedure. The apparatus was found to be capable of measuring fundamental magnetostatic quantities remotely, with a comparable accuracy to direct magnetometric equipment. Additionally, a favourable comparison with deperm data from real naval vessels confirms that the scaled apparatus permits a valid simulation of conditions during an actual deperm. The system of measurement presented can thus be employed to investigate the magnetostatics of the current deperm method and possible alternatives. Important qualitative differences between the deperm results for ships and those for submarines were noted though it was still possible to achieve effective simulation of both of these in the scaled deperm apparatus.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2002
- Accession Number
- ADA407882
Entities
People
- A. Bailey
- G. J. Russell
- T. M. Baynes
Organizations
- Defence Science and Technology Group