Author Topic: Tidying Up An Analoy 1401 Alloy Analyser (Read 30258 times)

vtsteam · « **Reply #25 on:** February 01, 2021, 11:59:02 AM »

If the pencil leads don't work out, I've purchased from this source before (for making graphite pistons):

https://www.graphitestore.com/Graphite/Plates-rods-and-tubes/Graphite-fine-extruded/custitem_shape/Rod

awemawson · « **Reply #26 on:** February 01, 2021, 12:27:53 PM »

Thanks Steve. I don't see why they shouldn't work. No doubt the binders etc will be different but they are probably organic.

Googling carbon arcs it seems that graphite vapourises at the arc temperatures so that is probably why it's easier to strike and draw an arc than with the tungsten point.

Pleasingly I did a test on some zinc billets today that I had from some previous work and it reported 100% zinc - of course it should, but this is the first test on a non aluminium based sample that I've done.

vtsteam · « **Reply #27 on:** February 01, 2021, 12:59:05 PM »

Wasn't doubting an experiment in advance of results, I'm looking forward to the test. Just providing a source of reasonably priced graphite rods that I know of.

Speaking of pure zinc and aluminum ingot tests, is there a supplied standard sample or test method used to calibrate these analyzers? In reading about spectrographic analyzers for metallurgy online, I read that they need frequent calibration.

Even if not, comparing test readouts for the two type ingots will help show whether any new electrodes produce different readings than the original included ones. Clays vary in metallic composition, and I wonder if various binders have any effect. If they do, and it's minor they could probably be compensated for.

Of course, I'm speaking from a personal scrap melting, ludicrously non-analytical perspective, but I am nevertheless curious about analysis -- that to me would be a great boon. I would not refuse the kind of kit you have!

ps, my guess is that dissolution of the carbon in graphite contributes to the plasma in a way that tungsten does not. And that eating away of the electrode is a desirable quality.

awemawson · « **Reply #28 on:** February 01, 2021, 01:13:36 PM »

As I understand it, each probe head was individually calibrated and the appropriate settings put in a custom EPROM. The instructions emphasise that they are not as accurate as lab instruments and always refer to them as Alloy Identifiers rather than analysers.

One of my two instruments has a group of test samples (about 1.5" square) of different alloys for comparisons.

I'll be attacking the second instrument in the next few days, as I recall they have slightly different firmware but I'll bore you with reports as I progress.

vtsteam · « **Reply #29 on:** February 01, 2021, 01:14:44 PM »

not boring....

Pete W. · « **Reply #30 on:** February 01, 2021, 02:07:25 PM »

Quote from: vtsteam on February 01, 2021, 01:14:44 PM

not boring....

Plus one for 'not boring'.

hermetic · « **Reply #31 on:** February 01, 2021, 02:11:32 PM »

plus another for not boring!!

vintageandclassicrepairs · « **Reply #32 on:** February 01, 2021, 03:53:56 PM »

Hi Andrew,
Definitely not boring

John

mattinker · « **Reply #33 on:** February 02, 2021, 04:08:53 AM »

Carry on boring us!!

awemawson · « **Reply #34 on:** February 02, 2021, 09:46:47 AM »

You are all too kind - I imagine you all snoring in front of your PC's

I dug out the second Analoy 1401 - I know that it has worked in the last few years but when I plugged it in, although I could strike an arc I got no indication on the LED bargraph of signal (rather charmingly they refer to these led bars as 'candles')

A bit of poking around showed that some of the decomposing foam had got into the 25 pin D connector for the probe - a quick blow out with compressed air and not only was it now working, but giving identical results to #1 on my ingot of LM2 alloy. This is good news and gives me the confindence to pull it apart and give it the same treatment the analyser #1 got last week.

My purchase of pencil leads to potentially make some graphite points turned up. These are 3.2 mm 5B leads intended for a propelling pencil . Quickly cutting off the end of one to make an electrode and trying it I immediately saw that the arc was burning significantly more fiercely. the electrode itself starts to glow and is much more fragile.

The test results differed greatly from the correct electrodes with the proportion of silicon showing higher at 23 % and iron also higher at 6.1% Now there are are presumably all sorts of binders added to the leads, but another variable is where the electrode sits in the chuck. Due to the engineering of the collet a 3 mm electrode sits more deeply than these leads at 3.2 mm. Now I know electrode height affects things. When I've tried to re-insert a used electrode and held it so that it sits a bit higher (to make up for burn back) and over egged it so too much sticks out some elements disappear from the print out. Presumably the part of the CCD device devoted to those elements isn't receiving light.

. . .all very complex . . .

vtsteam · « **Reply #35 on:** February 02, 2021, 10:51:20 AM »

Well clay definitely has silicon in it and often iron, too (particularly red clays) among other elements, and is a frequently used binder for lower quality "graphite" shapes. So though not a conclusion, is at least a possible explanation.

nrml · « **Reply #36 on:** February 03, 2021, 03:46:46 AM »

Will it be possible to work out how much the iron and silicon increases and deduct it from the results or does this vary with the strength of the arc and from pencil lead to pencil lead?

awemawson · « **Reply #37 on:** February 03, 2021, 05:46:30 AM »

Good questions NRML but I don't have the answers !

I have some 2B true 3.0 mm leads on order so they will at least fit the collet better but I expect they also will contribute elements to the analysis. As Steve says the clay binder is sure to have at least Silicon in it.

I'd hoped that if I could find pencil leads of the same hardness and blackness rating I'd be home and dry but thinking about it different manufacturers will achieve the same rating suitable for artistic use and indistinguishable BUT using differing constituent elements

Ideally I need to find somewhere / someone that can analyse / grade / identify what the proper electrodes are made of - I'm keeping the used ones on the off chance I find someone.

philf · « **Reply #38 on:** February 03, 2021, 07:03:16 AM »

Andrew,

On AliExpress: "3mm*100mm High Purity Carbon Graphite Rod Bar For Electrodes ,Smelting, Casting ,Scientific research Material" 10 pieces for £8.44.

https://www.aliexpress.com/item/32739517670.html

Sea.dog · « **Reply #39 on:** February 03, 2021, 07:50:28 AM »

Analyse a piece with an original electrode then test the same piece with a new electrode. Look at the differences between the two analyses and then rewrite the firmware

awemawson · « **Reply #40 on:** February 03, 2021, 09:21:21 AM »

Thanks Phil, I've ordered some but goodness knows when or even if they will arrive in these strange times we live in - at least if they are the purity that they claim contaminants won't be a problem.

Graham when I first got the Analoy's I thought about de-compiling the firmware - I've done quite a bit of 8085 coding in the past, but it's actually quite a daunting task going from binary with no idea what does what to a sensible assembler listing with meaningful labels. In fact it's rather like the 'Step 5' code for the Beaver TC20 lathe PLC that I did and took WEEKS over, but with rather less clues ! Though I guess there is a table embedded in there somewhere mapping 'CCD element' output to detected metallic element.

vtsteam · « **Reply #41 on:** February 03, 2021, 10:58:25 AM »

I think getting reasonably high purity graphite will solve the problems.

awemawson · « **Reply #42 on:** February 03, 2021, 11:40:16 AM »

I'm hoping so Steve, but that's a few weeks away as the graphite is on the classic 'slow boat from China' - probably as well as I'm getting too many projects all running concurrently

When doing soil sampling you mix it up in a jar, give it a shake and leave it to settle for a few days, and the differing particles settle out in distinct layers giving a good idea of composition.

I did wonder if I ground up a few of the used electrodes in a pestle and mortar with water and left them to settle it might reveal something, but being such a small sample would need to be in something like a small test tube.

Where the heck are my small test tubes

WeldingRod · « **Reply #43 on:** February 03, 2021, 12:38:21 PM »

Carbon electrodes for welding or arc gouging might be easy to get and shouldn't have funny stuff in them.

Sent from my SM-G892A using Tapatalk

awemawson · « **Reply #44 on:** February 03, 2021, 12:46:06 PM »

But not 3 mm diam I think ?

vtsteam · « **Reply #45 on:** February 03, 2021, 02:36:14 PM »

Quote from: awemawson on February 03, 2021, 11:40:16 AM

I did wonder if I ground up a few of the used electrodes in a pestle and mortar with water and left them to settle it might reveal something, but being such a small sample would need to be in something like a small test tube.

That would be interesting. Have done same with soil...

awemawson · « **Reply #46 on:** February 04, 2021, 10:19:48 AM »

A couple of positive results today

The postman brought two things for this project:

Firstly a 3 mm pencil sharpener - I'd never even considered that there were such things, but not only does it sharpen the graphite rods to a very suitable point, it, like me is left handed ! (there was the choice) and at £2.45 not worth mucking about with making something. Just need the right graphite now !

Secondly some scraps of green perspex to make a replacement UV screen for the arc discharge. The one I'd glued had broken again.

My first attempt was by tracing one of the original shields onto the perspex by hand, and with a combination of band saw, sanding disk and drill make a flat blank ready for bending. I made up a simple wooden jig as the bends have to be more than 90 degrees so that the shield grips the body. The shield is located by two pins projecting from the probe and it pivots on them as well, so the holes for these need to be aligned.

It didn't come out too well, and it was a this point I realised that the 'originals' were both hand made copies that not only differed from each other but either side of them was not a mirror image of the other!
OK draw it up in AutoCAD - I ported it to the laser cutter and cut a template from a sheet of gasket material to prove it fitted - it did

So putting a bit of perspex in the laser cutter I set it going. The cut was SO smooth and even compared to my hand made effort. So into the bending jig having been heated with an electric paint stripper, and out came a very acceptable UV shield

I will make two more while everything is set up, so both machines can have a decent shield and I'll also have a spare.

vtsteam · « **Reply #47 on:** February 04, 2021, 11:18:52 AM »

Very nice Andrew!

modeng200023 · « **Reply #48 on:** February 04, 2021, 11:38:25 AM »

Two things Andrew,

First, I never knew that left-handed sharpeners were made let alone available.
Second, your left-handedness explains how and why you are able to dip your toes into so many things and come out winning.

John

awemawson · « **Reply #49 on:** February 04, 2021, 11:58:30 AM »

John it's fool hardy ness not left handed ness

I suppose a lifetime fighting against the system probably helps - you should have heard my Sgt Major yelling at me when we were doing Bren Gun training and I was doing it left handed. Much insistence from him for holding it right handed accompanied by words I didn't understand only increased by me pointing out that I HAD to sight it with my left eye as the other one was missing.

Oh was he pissed off when I actually scored pretty well in the squad both at 100 yard butts and 500 yard butts with falling plates

. . . then there was the Enfield No 4 where my left hand had to go over the charging port to operate the bolt . . . .but that was another story that did little for his blood pressure

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Author Topic: Tidying Up An Analoy 1401 Alloy Analyser (Read 30258 times)