Re: [CAD_CAM_EDM_DRO] Fw: Magnetostrictive sensor DRO

I have a couple of them around here somewhere but I have not had time to play
with them. Your description is good but I think (but do not know) the accuracy
is not that good.
Bertho Boman
============================

Murray Leshner wrote:

> >Has anyone ever run into one of these?
> >
> >At my last 'real job', the company made underground storage tank level
> >sensors. A stainless steel tube with a special nickel alloy wire
> (Ni-Span-C)
> >with a unique thermal coefficient of expansion characteristic inside spans
> >the distance to be measured. A non-contact annular (toroid or
> >doughnut-shaped) magnet is connected to the linear translation mechanism
> and
> >induces a magnetic stress in the wire corresponding to its position. The
> >wire is 'twanged' like a tuning fork and an echo or reflection is induced
> by
> >the magnet's position.
> >
> >By measuring the time delay, the position of the magnet can be determined.
> >It's not a DIY device, but I was told it's origin was the CNC machining
> >industry. They can be immersed in liquids including gasoline...I don't
> >recall the accuracy...seems 0.0005" was what they were talking about, but
> >that's measuring the depth of liquid in a 10-15-20 feet tall tank, so in
> >that situation it's more than adequate.
> >
> >Magnetek in the Royal Oak (Detroit suburb) area in Michigan seemed to be
> the
> >big foot in the industry, if anyone wants to pursue it.
> >
> >Murray