# newbie question. dentists x ray machine



## blanco1972 (Jul 22, 2008)

hi im pretty new to the scene .im collecting a x ray machine from a dentist tommorow can any one tell me if theres anything worth removing from it.


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## Anonymous (Jul 22, 2008)

Aside from the radioactive Strontium 90 which powers the "X-rays" I am sure there are circuts and other chips in there that contain values.

Mined sending me the strontium?


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## Lou (Jul 22, 2008)

I'm fairly certain that Sr-90 is not what is used, at least not in anything in the past 30 years. I'm even more certain that sending that through the mail would be a bad idea. Just in case you weren't sarcastic about this.

Much like the x-ray source in an XRF or EDX machine, it is generated via HV action usually with a copper cathode.


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## Anonymous (Aug 18, 2008)

Actually I am a research chemist and XRF's so use a radioactive source, often Cd or Am. But reg's now make you be registered and certified to buy/dispose of any radioactive hazmat.


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## Lou (Aug 25, 2008)

Hm, maybe for a small table top unit then or an old, old machine otherwise, I've never seen it. Perhaps for a small XRF where a large high voltage system would be unwieldy. 

I know my XRD and EDXS both use cathode based systems.


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## Chumbawamba (Feb 6, 2009)

Sorry to pick-up an old thread.

I recently got in an x-ray machine and checked with a knowledgeable friend and he said that the x-ray tube will have either a platinum or tungsten target. I extracted the tube from the machine I have and am waiting to test to see what I have. If it's platinum then there looks to be at least half an oz (providing I'm identifying the parts correctly, which I might not be).


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## butcher (Feb 7, 2009)

some xray tubes do have PGM coatings on the target spinning disks, but I would check the value of these tubes can be more than the metals, even if the tube is bad, many are collectors Items, a couple of friends of mine works on xray equiptment, one of them has an enormous tube collection.


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## Chumbawamba (Feb 7, 2009)

Well, I wasn't planning to break the tube, but I carelessly put it on the ground next to my feet as I was trying to deal with the mineral oil that was pouring out of the housing in which the tube resided (the tube and the transformers into which it is fixed are immersed in mineral oil for cooling). When I barely stepped on it with the tip of my foot the lubrication provided by the oil caused the tube to go into a dramatic spin, and it ended up hitting something and breaking open. Oh well. That settled that.

The tube I have has a date of October 1963 stamped on the external housing. I wasn't able to identify the tube from the part numbers on it. I'm posting photos with this comment. Perhaps your friend might be able to help identify it?

Interestingly, it looks a lot like this tube in its internal elements:

http://www.alibaba.com/product/nago-10870377-0/Nago_Stationary_Anode_X_Ray_Tube.html

...though it is clearly not the same tube.

In fact, my tube looked a LOT like this one when it was still assembled (pre-leadfoot):

http://www.orau.org/PTP/collection/xraytubescoolidge/grossshockproof.htm

The housing on mine is definitely some sort of ceramic, quite possibly lead-infused.

Anyway, I hope I didn't destroy something of great value. That would suck. But now that it is destroyed there's no point oin crying over spilt mineral oil...may as well go about recovering whatever PGM it contains.

See photo and accompanying comments for more information.


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## jimdoc (Feb 7, 2009)

When I was trying to find info on the metals in the xray tubes I have I seem to remember berylium being mentioned so be careful as to how you test the metals. I will post a picture of the two I have later, I think they are from the twenties or thirties. I wanted to break one open, but decided to keep them intact.
Jim


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## butcher (Feb 7, 2009)

I will check with them one worked for GE and the other Siemens, both work on hospital Xray equiptment, not sure how much expierience they have with dental xray tubes, sometimes when parting out old xray equiptment I will get their leftovers, some of the transformers are really heavy in copper, and usually alot of switch's and fancy sensors, most of this stuff is top of the line electronics comparible to military grade.


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## turtlesteve (Jun 30, 2010)

I dismantled a dental X-ray machine a few years ago and this is what I learned:

1. I found no precious metals to speak of (1950's era unit). The anode in mine was tungsten but was a large rotating type.

2. There should be no major radioactive source or Be in dental x-ray tubes (glass windows are used instead). Only exception is the filament coil may be thoriated tungsten.

3. Usually the x ray tube is a glass envelope but often looks metallic colored - this is from vaporized anode metal that condenses on the inside of the glass.

4. Only scrap value I found was copper, lead, and steel.

Steve


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## Anonymous (Sep 11, 2010)

turtlesteve said:


> I dismantled a dental X-ray machine a few years ago and this is what I learned:



Hi, I just joined this forum today and saw this post. I was in the dental equipment repair business for over 25 years. One thing I remember learning along the way was that some of the '50s era and older x-ray tube heads contained PCBs (hazardous to your health) in the oil. In fact, a dentist once wanted me to haul off his old x-ray, but I told him he had to contact appropriate authorities to have it disposed of according to regulations. This was all in Washington state, USA. It might be worth your while to be sure you keep from contacting this oil, and also check regs in your area.


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## Anonymous (Sep 11, 2010)

Just to clarify; PCBs in this sense are polycloro bromides-not printed circuit boards!


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## Harold_V (Sep 11, 2010)

mhmslm said:


> Just to clarify; PCBs in this sense are polycloro bromides-not printed circuit boards!


I think you mean polychlorinated biphenyls, yes?

Welcome to the forum. 

Harold


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## Anonymous (Sep 11, 2010)

I think you are right, it's been quite awhile. The point is, though, it's hazardous. So I was told. Thanks for the correction.


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## Harold_V (Sep 11, 2010)

mhmslm said:


> I think you are right, it's been quite awhile. The point is, though, it's hazardous. So I was told. Thanks for the correction.


Yes, it is hazardous, and very expensive to dispose of properly. 

I've been involved in two circumstances in which I faced just that. Solid waste that is registered in one's name is tracked endlessly, so if objects are placed in approved locations, should they ever require further handling, the rightful owner is still responsible. 

Key to this problem is to NOT get involved with PCB's for any reason. 

Harold


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## Anonymous (Sep 11, 2010)

I'm just glad I passed on that one


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## Stevious (Oct 24, 2010)

Harold_V said:


> mhmslm said:
> 
> 
> > I think you are right, it's been quite awhile. The point is, though, it's hazardous. So I was told. Thanks for the correction.
> ...



Just to add emphasis to this fine warning. *Any* transformer that has "oil" in it should be suspect PCB's. As far as I know, all the X-ray machine transformers from the 50's had PCB's. Poly-chlorinated-biphenyls = It's plural for a reason. Within the transformer, heat builds up and though the oil circulates the heat, the PCB's which originally were perhaps a dozen various PC-biphenyls undergo changes creating newer different molecular shaped molecules, some of which are intensely carcinogenic or mutagenic.

PCB's are absorbed into the skin, orally absorbed, or if burned many thousands of molecular variations (often of greater carcinogenicity) are produced and can be inhaled. If a person attempts to "burn" the residual oil off a transformer core it would become a mini-ecological disaster. Beware of transformers! (Note: this also includes pre-1960'ish (exact date?) fluorescent light transformers (the small rectangular ones). Last I knew, nobody in America (professionally speaking) was accepting PCB's for destruction, professional collectors were storing them until a decision on how to destroy them (probably injected into a plasma stream will be the way) was decided. Skin contact can cause chloracne, a chronic skin condition that is disfiguring, and can lead to increased tumors within the colon and other areas of the body.


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