Erratic edge finder

I've been using the edge finder below for many years and have always had consistent results to within 0.02 - 0.04mm. Recently the edge finder started behaving erratically with really inconsistent and erroneous readings. Much head scratching ensued and I could't figure out why. Then i noticed it was working fine on non-ferrous metals and the penny dropped. The probe of the edge finder had become very slighly magnetised. Not enough to notice it sticking to anything but enough to give the aberrant reading and enough to pick up iron filings. Quick demagnetisation and its all back to normal. I'm sure that I am not the first to have this issue but I had never come across this before so thought it worth sharing...

Interesting to know, thanks

Well I never - another trap for the unwary! Thanks for sharing.

Dave

Well I'll go to the foot of our stairs!

I've just read this and checked my edge finder:

and it too was slightly magnetised. I've noticed lately that it was getting a tad inconsistent but of course blamed myself for poor technique. Now degaussed so all should return to normal except with me looking for different excuses for my poor workmanship.

Thanks for raising the subject Ifoggy.

Jim

Brilliant! Thank you! Who would have thought it? Another example of the incredible pearls of wisdom and knowledge that can be found in this forum.

Incidentally, old tape-head demagnetizers work well on small tools. I'll have to go on the attack with mine again...

Great tip Ifoggy, I would never have thought of this.

Neil