MAGNETIC FLUX DENSITY AT SURFACE OF INDUCTION MOTOR BODY

Why do u want to measure the flux density at motor body?

Navy requires low magnetic emissions from electrical devices as these pose a danger of interference to other electronics. But they have no specifications of these but want lowest possible magnetic flux densities around electrical equipment. A standard has to be evolved and experts are working for a standard - hence this request.

I love this community for thislike questions you ask. I will study this.

regards

I have a device by Walker Scientific called a "Gaussmeter DVG-1T that outputs 1 mV per gauss (designed to be used with a DMM), with a resolution of 0.1 G and an advertised accuracy of +/- 5%. I have never used it for your stated purpose, using it mostly to explore properties of magnets (although it does seem to be able to resolve earth magnetic field...which can have an effect on readings on other magnets). I have had this unit for several years, so I do not know if it or similar units could meet your requirements. If I remember rightly, I purchased this from Davis Instruments.

Regarding using this to evaluate flux density around a motor, it should be possible. Developing standards and interpreting the results is a totally different matter...

I can not found a regulation and/or standard concerning field density on body of the Ind Motors (i'm not surprised though). This is another matter to discuss but it might possible to count induced currents -harmonics etc-in terms of earth currents.

In today's issue of EDN Analog on line, there is a good review of magnetic flux measurement techniques that may prove useful. Written by Paul Rako. I did not have time to read the entire article, but I do not believe it addresses this specific application directly. However, there is some good basic information regarding various measurement techniques that you may find useful.