Gaussmeter found dead

[Joe Gwinn]

Shrink tubing that can be slid into place after soldering and shrunk down over the center knuckle is one way to solve the problem.

I had an idea to eliminate the knuckle and insulate the solder joint. The reason for the knuckle was to mechanically fix the leads together for soldering. But one can use a short length of tight-fitting teflon tubing to hold the wires in parallel contact while being soldered. Teflon will not be harmed by soldering.

One can also get heat-shrink teflon tubing, so one could make the joint by putting a bit of solder in the tube with the wires to be joined, and heat shrinking the tube, using enough heat that the solder melts and completes the joint.

Zeus PTFE heat shrink teflon tubing: [ame=http://www.amazon.com/gp/product/B000FMYV9E/ref=pd_lpo_k2_dp_sr_2?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B000FMWSGC&pf_rd_m=ATVPDKIKX0DER&p f_rd_r=04VSNZF1NRAJNJPEXSCT]Amazon.com: Zeus PTFE (Teflon) Heat Shrink Tubing, 18 Gauge, 0.006" Wall, Shrink Rat 2:1 48" Length: Industrial & Scientific[/ame]

[David Schwab]

...but nonferrous metals and plastics are simply invisible to magnetic fields...

Wouldn't waving a non magnetic conductor past a magnet produce eddy currents? They would be small, but if the sensor is sensitive enough, those small magnetic fields might change the reading?

I haven't tried that, but I did put some silver marker on the sensor side so I could see it, and I noticed after that I was getting a 1 Gauss reading with no magnet around. I scraped the paint off and it stopped.

Now it might have been the paint. I don't know what they use in those metallic markers. Nickel maybe?

[David King]

I have to agree with David here that a nonmagnetic metal object near the field will have a small eddy current induced and might have a tiny effect on the field being measured. I doubt it will be statistically significant and I imagine will only have an effect while the probe is in motion relative the the magnetic field.

That said MY undergarments are all in a bunch over this question. I think all future operators of Gauss meters should licensed by a suitable governing authority!
There is just too much at stake here.

[Joe Gwinn]

Wouldn't waving a non magnetic conductor past a magnet produce eddy currents? They would be small, but if the sensor is sensitive enough, those small magnetic fields might change the reading?

Yes, but only for a few milliseconds at most.

I haven't tried that, but I did put some silver marker on the sensor side so I could see it, and I noticed after that I was getting a 1 Gauss reading with no magnet around. I scraped the paint off and it stopped.

Now if might have been the paint. I don't know what they use in those metallic markers. Nickel maybe?

The metal dust in those markers is usually aluminum.

It's pretty hard to measure to within one gauss with this instrument using a handheld probe, so I wouldn't trust the results. If one will test the effect of silver paint, I would instead set up a magnet and the probe in some kind of frame made of plastic with a space between magnet and probe. Measure gauss with and without a piece of plastic with the paint, and see if the reading changes. Nickel dust paint might make a difference, but aluminum will not.

Nickel dust paint will be somewhat magnetic, to the point that a magnet may be able to pick a painted piece of plastic foil (film) up, so this may be a good way to cross-check.

The Shielding paint used in the cavities of a guitar contains nickel plated copper dust, and so could be used as a test case.

[David Schwab]

The metal dust in those markers is usually aluminum.

That was my first thought.