Magnetic Induction: Investigating Unmagnetized Pipe

[Areena]

Hello, I wasn't really sure as to where to post this, since it kinda doesn't really fit in with the listed categories, but I have a question. I work at a chem lab that specializes in Non-Destructive testing, and I am also minoring in Non-Destructive testing in college. In the engineering department, a long metal pipe was magnetized using a large magnetic coil of 120 turns, and it never overlaps itself. Only, the pipe did not develop a negative end and positive end like a magnet. The charges on the pipe are as shown in the attachment picture. I was asked why this is. The only things I could come up with were that it could be the material of the pipe, the length of the pipe, a flaw in the pipe, or the amount of voltage/amps used were too low to magnetize the pipe. The coil used 80 volts, twice that of what the company says is a safe level of voltage to use. No one can seem to figure this out, so hopefully some of you nice smart people can help me determine why this is, or if I am just having a stupid moment, and overlooking something obvious. Anything is appreciated. Thanks!

~Areena

 

[Drakkith]

How did you guys determine the charge at specific points on the pipe?

 

[pallidin]

Why would the static magnetisation cause a potential differance?
That's new to me.

 

[Areena]

Well, I did not do it, someone in engineering did, but they used a Magnetometer for DC magnetic fields. I do not believe they pinpointed the exact locations of the charges. The picture is just an example of what was found using the meter after magnetization of the pipe.

 

[pallidin]

OK, but the meter was a magnetometer. Right?
It does not measure electrical voltage, rather magnetic strength and polarity.
Perhaps this is the source of confusion.

If not, I'm all ear's.

 

[Drakkith]

I could see that palladin. I have a hard time believing that there was a difference in charge on a metal pipe. The charges should dissapate and the pipe should be the same charge at all points. Right?

 

[pallidin]

...I have a hard time believing that there was a difference in charge on a metal pipe...

That is my thought as well.