The Craftmans Shop > New from Old

Tidying Up An Analoy 1401 Alloy Analyser

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Years of hoarding, avarice, and scanning the small ads Steve  :clap:

So I couldn't leave it at that, and came back out to the workshop and cleaned the foam and glue off the probe storage chamber - horrid job but it's now done.

Then I realised that there are two miniature fans amongst the electronics - both with degraded foam filters - so those got removed and new filter material installed.

If you see the holes in the side of the probe chamber - I think that those were ventilation through the OPEN cell foam that was originally installed as padding so I now need to think how to provide the same ventilation but using my closed cell foam. I may just cut corresponding holes in it!

The probe 'arc shield' had glued over night so it got re-fitted.

Today's job: start gluing neoprene foam on.

Should be fairly straightforward were it not for two issues. Firstly putting it in restricted spaces is tricky as the pre-glued sheet sticks to anything it touches, and secondly, like a prat I put the main instrument into the case to draw an outline where the base foam is needed, fixed the foam, then realised that I'd put the instrument in at 180 degrees  :bang: More foam removal and cleaning !

Eventually all back together so before I investigate the probe I wanted to prove that the main instrument still worked. I'm glad to say that it did and correctly identified 'LM2' as LM2 giving me confidence that I've not disturbed anything vital.

It was then that my  five 8.5 kg ingots of pure aluminium were delivered. Pleasingly the analyser agrees with the supplier that it's 'LM0'  so a nice confirmation that the results are reasonably accurate.

Irritatingly, having lined the 'probe pocket' in the case with what I thought was the same thickness (10 mm) foam I find that the probe no longer fits and I had to remove it - oh well you can't win 'em all !

So next item on the list is the probe itself - pull it apart and see how it ticks !

So time to open up the probe head. Never been in here before - all I've previously done is make a repair to the umbilical cord using self amalgamating tape, and replace the window glass that protects the lens. This is no more than a lab slide 'cover glass'

So nothing ventured nothing gained - out with the Allen keys - carefully cut round the tamper seal - and see what we have.

Well  as expected, rather a lot of electronics. The emission from the arc shines through the cover window, passes through a lens and enters a 'long black box'. The far end of this box has a 16 pin ribbon cable. Now I assume that there is a prism and the emissions are spread out down the 'black box' and impinging on a sensor of some sort.

I strongly suspect that the sensor is a 'CCD' or charge coupled device as I found a patent by the company using those devices for spectral analysis . Or maybe they have a sensor dedicated to each element that they are interested in - I don't know, and I wasn't prepared to dismantle the box or I expect the calibration would be all over the place.

Anyway I thought it prudent to carefully re-assemble it before I break it. I replaced the optical window and tested that it still works - phew - it does !

A bit more information has come to hand.

Studying the scraps of circuit diagrams that I have, which are incomplete and fuzzy, there is reference to the CCD !

Also the instruction book has a description of what can only be my 'black box' - glad I didn't open it !

Aha, so refraction to discern the different wavelengths (elements) and a CCD to place the position and amplitude of each.

Those electronics assemblies were the life's work of several people - many man years there!

So it was assembled and tested late 1990. Interesting / encouraging to see they are still in business. I wonder how their current products compare in terms of the technology in use.


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