# Identification of unknown components



## Kubik_Rubik (Apr 9, 2021)

Hello,
I'm usually able with a little effort to identify the components, but in this case I'm helpless. The first looks like a classic "gold" transistor from below, but contains two fragile sticks and is filled with putty. I have no idea what they are and what equipment they were removed from, because the colleague who once collected them died a few years ago. I have about 70 of them, I wonder if the sticks contain something valuable, or I should process only the gold-plated bottom, like classic transistors. 










The second picture shows a part from an old Czechoslovak industrial device. According to the code, I did not find anything, but these are three solidly gold plated boards with circular contacts. What would I wonder if the riders who ride through these contacts are made of some precious metal? I know sometimes they are gilded, in this case they have silver color. Please do not know what metal these types of riders are usually made of? 










Thank you all for the information and I wish you all the best.


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## butcher (Apr 9, 2021)

Do you have pictures of the parts before you tor this apart? Did they have any identification numbers on the case, looks like some type of resistance built into the switch mechanism, I have no clue of what this is but it looks like some type of sensors, where did they come from can you provide more clues to the guessing game of broken parts.


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## nickvc (Apr 10, 2021)

Lots of the old eastern bloc electronics have precious metals in them, my advice is to test every part, some contacts were made of gold alloys others platinum or palladium or alloys, the plating is usually heavy so get testing and tell us what you have.


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## g_axelsson (Apr 10, 2021)

The first component looks like an oxygen or other gas sensor. I would test that gray silvery part if it might contain PGM:s

The rotary switch is normally gold plated but I've seen solid gold alloys too. With welded wires like that I would expect a solid gold alloy and test it. Will a bit of nitric acid in a test tube dissolve it all, leave a hollow tube or a solid wire?

Göran


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## Kubik_Rubik (Apr 10, 2021)

*butche*r: Unfortunately I do not have. I work in our small scrap yard and a colleague who disasambled electro scrap died suddenly and did not have time to pass on his knowledge to me. I found a box from biscuits full of these parts in the workshop and I'm trying to find out what it is. 

*nickvc*: I know, I have already accumulated some small treasures, such as thick gold-plated pins, Au/Pd pins, Pd - capacitors, etc. but I'm still learning. 

* g_axelsson*: Thanks for the tip, I'm still in recovery mode, too much work / little time. But in half a year I might have a small "lab" with a fume hood. I only have 38% nitric and DMG on the way, but I'll try to test those welded wires and I'll let you know. Does HNO3 have to be hot, or is room temperature and more time enough?

I'll have those gray-silver parts and contacts from the rotary switch analyzed with an XRF gun as soon as I can, and I'll let you know. 

Thank you all for your suggestions.


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## Kubik_Rubik (May 16, 2021)

Hello, so I finally know the composition of the "gas sensor" and the gold layer of the circular switch:
- on the ceramic part of the sensor there is a layer containing: 33.14% Ag, 60% Pb and 5.8% Nb. At first I was glad that there is 60% Pd, but I saw a screenshot of an XRF gun and it's really lead 

- The contact layer of the rotary switch contains 66.41% Au, 22% Cu and 9% Ni.

I haven't analyzed the welded contacts yet, but I'll let you know as I collect more and process them.

In the future I will definitely have more results from the analysis of unknown e-components using XRF, so I will definitely share with you.


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## g_axelsson (May 16, 2021)

Kubik_Rubik said:


> - The contact layer of the rotary switch contains 66.41% Au, 22% Cu and 9% Ni.



Sounds impressive but is more a display of how you could use an XRF to measure layer thickness rather than the composition of the contact area.

An XRF is using X-rays to excite the atoms in the target area. Most of the X-rays is absorbed in the surface layer but some penetrates deeper. The deeper the less radiation. When an atom is excited by an X-ray it gains energy. This is an unstable condition for the atom and in a short while it relaxes and emits an X-ray. The XRF measure these X-rays given off from the target material and makes an assumption that the alloy is homogeneous and then try to match the measurement to an alloy.
In reality the X-rays are mostly absorbed by the gold plate, some are absorbed by the nickel strike below the gold and a few gets down to the copper layer. The emitted X-rays from the different layers mixes together and the instrument tries to match it against a solid.

So the thinner the gold plate is, the more of the nickel and copper will leak through. So that effect is sometimes used to check for plating.

In your case, the top layer should be 98 % gold or better.

Göran


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## nickvc (May 17, 2021)

Looking at the rotary switches I think they are heavily plated but you will need a fair amount to get a good yield, the contact wires could be the money in comparison.


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## Kubik_Rubik (May 17, 2021)

*g_axelsson:* Thank you very much for explaining Göran, it makes perfect sense and it is true that the proportion of gold seemed to be too good. To be honest, I wasn't too interested in the content of gold, but if palladium is present in addition to gold, so I can sort them properly. For example, as in some East German contacts (fortunately it's written on them) - I just don't know if it's an Au / Pd alloy or if the metals are in layers.

*nickvc:* I know, I'll just cut them out and put them to my golden fingers. Looks like there's no gold under the green mask. I'm also curious about the composition of the contact wires. When I finish the lab, I have to test them.


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