Re: ATM Foucault tester

["A. Suykerbuyk" <asuyker@wxs.nl>]

Martti,

I like the laser diode idea. However, 0.8 mm, isn't that too large a
dimension?

Thanks,
Adrie Suijkerbuijk.


>

>laser pointer is one of the best light sources for Foucault Ronchi and Wire
>test (and acceptable for interferometer). But as Anthony stated, you must
>expand the beam.The 2-3 mm spot itself is of no use.
>
> The collimating lens MUST be remowed. The emitting area is something like
>0.03 x 0.8 mm and is very good source. Sometimes it is not easy to remove
>the collimating lens and it is best to  buy not a laser pointer but
>separate laserdiode and electronics for it ( in one unit). Then it is
>trivial to remove the lens.
>
> As a laser the beam is too bright and too monochromatic for F, R and W
>test.
>
>Put a 1K-ohm potentiometer between  pointer electronics  and battery to
drop
>the current. At about 20-30 mA the laser stops laserating.and you have very
>bright and safe source and the brightness can be adjusted in your liking.
>The color is the same as in normal red diode.
>
> Please ask if I did not make myself clear.
>
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>
>Martti Koskimo
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