EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: Hugoneus on May 16, 2017, 04:08:10 am
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I have been searching for a bench-top X-ray machine for a while now with no luck. Any suggestions? It would be very helpful in my videos.
Cheers,
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Member Fraser is our X-Ray expert.
Hunt through his Topics.
https://www.eevblog.com/forum/profile/?u=2435 (https://www.eevblog.com/forum/profile/?u=2435)
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A dental head works reasonably well for this sort of thing, they're compact and well shielded. Not very powerful but they do have a nice small focal point and when you're imaging inanimate objects that don't move or suffer from radiation exposure it's not a problem to take relatively long exposures. Ideally you want the whole machine so you don't have to mess with driving it.
You'll need a cassette and film too, mammography film and cassettes has a single sided emulsion which trades sensitivity for high resolution. Radiography film can be developed with ordinary photographic chemicals.
The biggest issue is regulatory, I don't know if there's a legal way to operate one in your home and I'm not going to offer advice on that topic other than be careful. Xrays are potentially dangerous and even a small dental system is capable of causing serious injury or death if you are careless or negligent enough and if you somehow manage to expose anyone to radiation it leaves the door wide open for serious liability. Nothing stirs up hysteria like the word "radiation." A commercially built fully enclosed and interlocked parcel inspection system is probably the best approach if you can find one.
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Perhaps a mailroom X-ray unit such as Mike detailed here:
https://www.youtube.com/watch?v=aCc83fh1Mt8 (https://www.youtube.com/watch?v=aCc83fh1Mt8)
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If you are considering to build an X-Ray bench machine by yourself, this may be a good starting point:
http://www.ebay.de/itm/Miniature-X-Ray-tube-for-x-ray-photography-and-research-Cold-cathode-Rare/252679396257 (http://www.ebay.de/itm/Miniature-X-Ray-tube-for-x-ray-photography-and-research-Cold-cathode-Rare/252679396257)
http://www.ebay.de/itm/X-ray-Image-Intensifier-Screen-for-experiments-with-x-ray-tube-x-ray-photografy/261604110323 (http://www.ebay.de/itm/X-ray-Image-Intensifier-Screen-for-experiments-with-x-ray-tube-x-ray-photografy/261604110323)
But! Be careful! X-Rays are nothing to play easily with! Do all experiments with the radiation well shielded! Behind thick layers of lead!
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Look for a Faxitron MX-20 with the PC and software. Nothing you build with a dental tube or mail scanner is going to have decent resolution.
The Faxitron is almost more like an X-ray microscope.
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On the contrary, a dental head with mammo film can produce stunning resolution, as in you can clearly see the bonding wires inside SC70 and similar parts. Nothing accessible to the hobbyist rivals the resolution of mammography or single sided industrial radiography film. The focal spot is very small since they are normally used with a very short distance. At a longer distance capable of covering a larger sized cassette you will need exposure times of a second or longer but that is not a problem for inanimate objects.
You do need to take care not to overheat the tube though. There is typically no way to directly monitor the anode temperature.
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Here in the US the rules vary by state, but almost all require a licensed X-ray technician to be able to buy X-ray equipment. Sellers at public sites like Ebay are pretty scrupulous about license verification even if it isn't required at your location. It is easier for them to say no than it is to become conversant in all of the variations in rules and regulations.
Licensing isn't impossible, particularly for non-medical licenses, but in my location it is a significant and ongoing nuisance that I have chosen not to deal with.
Whether you decide to go legal, or find some way to skirt the law be careful. You don't want to emulate Madam Curie and other earlier investigators in high energy radiation by dying of your curiosity.
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I've bought at least half a dozen xray heads and tubes from ebay sellers and have never once been asked to provide any sort of license. You can buy pretty much anything you want, possession is perfectly legal. Now if you want to operate it that's another matter, I no longer mess with that stuff at home since I have access to a proper machine in an actual legal installation. I did acquire that machine myself though, no license, I simply had to sign a waiver and haul it away for free. The clinic was going to have to pay $600 to have it removed and disposed of. I repaired it and traded it to the current owner.
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I recently configured and tested a Faxitron DX-50 high resolution table top X-Ray machine. It has the large 120mm x 120mm Hamamatsu imaging array and 35KVp available to the Microfocus X-Ray tube. The PC I configured for it is a MSI Hetis that has plenty of pprocessing power for teh task. The DX-50 is controlled using a RS232 serial link and the camera is USB linked. A laptop can replace the PC if desired. Pictures taken during my testing are in my X-Ray images thread.
https://www.eevblog.com/forum/projects/the-x-ray-image-thread-by-aurora-various-electronics-via-x-ray-imaging/msg1161087/#msg1161087 (https://www.eevblog.com/forum/projects/the-x-ray-image-thread-by-aurora-various-electronics-via-x-ray-imaging/msg1161087/#msg1161087)
If he has not already sold it, the owner may be contacted here:
Howard Furr-Barton
Medtech-Supplies
The Rectory
Park Lane
Blunham
Bedfordshire
MK44 3NJ
United Kingdom
info@medtech-supplies.com
He deals in Medical surplus and is an experienced international shipper of large and/or fragile equipment.
Tell Howard I sent you and you may get a better deal. Present price is around £2500 for such a machine. It is a turn key solution with all configuration done and the unit tested for correct operation.
Fraser
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On the contrary, a dental head with mammo film can produce stunning resolution, as in you can clearly see the bonding wires inside SC70 and similar parts. Nothing accessible to the hobbyist rivals the resolution of mammography or single sided industrial radiography film. The focal spot is very small since they are normally used with a very short distance. At a longer distance capable of covering a larger sized cassette you will need exposure times of a second or longer but that is not a problem for inanimate objects.
You do need to take care not to overheat the tube though. There is typically no way to directly monitor the anode temperature.
Resolution isn't just a property of the sensor, but of the tube itself. While the Faxitron doesn't have much penetrating power, you can get up to 5x magnification by placing the sample closer to the source. That's the part that's hard to achieve without a microfocus tube, and from what I've seen, dental X-ray machines don't use microfocus tubes.
My favorite Faxitron shot so far is this one, of a 5x7 mm IC package. The combination of 5x magnification and high pixel density at the CMOS sensor really gives you a good idea of what's inside:
(http://www.ke5fx.com/LMK61E2_xray_30kV_20s_MX20_57839.918558.png)
A dental X-ray looks more like a 1:1 scale image due to the lack of magnification and low pixel density:
(http://www.thegleam.com/ke5fx/hpll/xray1.jpg)
Yes, under the right conditions you could sort of make out bond wires, and I didn't mean to sound like the stereotypical EEVBlog "oscilloscope snob." :) I would have been very happy with a dental system if I hadn't learned about the Faxitron on here. But at the end of the day neither a dental-grade tube nor a dental-grade sensor is ideal for revealing high-resolution detail. You might achieve comparable results with a dental tube and a high-end sensor, but the Faxitron's turnkey nature is really nice. No hacking and mixing/matching of components is needed if you get the PC with it.
From what I've seen of Shahriar's interests, he would be best served with a plug-and-play specimen cabinet machine, or one like the benchtop unit in Fraser's post.
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Yes that is impressive, if you can find one then a machine like that has definite advantages. I found that I could achieve magnification by placing the film further from the subject but in practice I rarely did that.
Here are a few sample images that were taken with a dental head back when that was all I had access to, on a mixture of mammo, general diagnostic and industrial film. It's probably not as good as you might get from one of those Faxitron machines but I still think it's pretty impressive for $250 investment in equipment and supplies. The limiting factor is the scanner I used to digitize the film, a digital sensor is my holy grail for this stuff.
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Here are a few sample images that were taken with a dental head back when that was all I had access to, on a mixture of mammo, general diagnostic and industrial film. It's probably not as good as you might get from one of those Faxitron machines but I still think it's pretty impressive for $250 investment in equipment and supplies. The limiting factor is the scanner I used to digitize the film, a digital sensor is my holy grail for this stuff.
Those do look great. Your exposures are on the order of 1 second?
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Something like that. Those were all done around 8 years ago so I'm a little fuzzy on the details. Once I got access to a proper machine in a sanctioned location I stopped messing with the little heads.
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I have access to a dental xray head and digital sensor (CCD wired in directly to the computer which displays image almost instantly without need for chemicals or scanning). The only problem is the size of the field is quite small, as the digital sensors I have are usually Type #1 and #2 which are the size for intra-oral dental radiography. The biggest one is maybe 40mm diagonal, so it is really only useful for small devices or taking small fields.
I can take a bunch of xrays of various things I have laying around and upload them here, see if they are any good. The main problem with making your own device is the need to purchase an Xray head and hopefully a functioning tube in case it is old or not working. Regulations may restrict who can buy these. Also, if you are looking at wet chemistry you will need film and usually they come with lead shielding which you have to dispose of, plus all the chemical baths and you will either have to manually develop or get another machine which auto-develops, and they are not cheap.
Using a phosphor-plate system will cost even more, the film is re-usable but then you need a scanner which is also not cheap. Finally, a digital CCD type wired sensor is going to cost a fortune. So your best bet is if you have access or make friends with a dentist or doctor or radiologist, go to their clinic and use their equipment.
How would you do it? I can't see any easy and cheap way here in Canada to acquire the equipment needed to be self-sufficient taking xrays and getting images processed. If I did, I'd have bought my stuff through these ways rather than the oligopoly of dental supply companies here in Canada and need to get approval through Health Canada regulations.
I'll post some photos and xrays soon so you can get an idea of the quality possible. My stuff is about 8 years old now so it isn't the best sensor out there.
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You can buy the heads on ebay, like I said, I've bought at least half a dozen dental heads and other tubes from ebay sellers and nobody has ever asked for any sort of certification. As far as anyone is concerned, I'm buying parts, not complete machines, and they're for collecting, not operating. Same with film cassettes and film. Not sure what you mean about having to dispose of lead, the film just comes in cardboard boxes with a light-proof plastic envelope inside. To develop it you need ordinary photographic film developer and fixer, I bought that from a photographic supply place called Adorama. You can get developing trays but they were a bit too small so I got a couple of plastic storage bins at Target that I use as developing trays. For the safelight I used a small red LED bulb in one of those socket adapters that plugs into the wall. I never worried about precise developer mixture and temperature, I just watch under the safelight while agitating the tray. It takes about 10 minutes to set up the darkroom, a minute or two to develop each film, then hang them up on clips to dry for a half hour or so before handling.
Are the rules different in Canada than in the US? I was offered an xray machine some years ago from a vet clinic in Canada but I didn't want to try hauling it back across the border. You might check ebay for items already in Canada, film for example, I bought a lot of it as expired stock which was cheap. I bet if you ask around at hospitals and vet clinics you can find some expired film, speaking from experience it works just fine, even expired years ago. I use my own film when using the big machine at my friend's business and I'm still using the film I bought back when I started doing this stuff.
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I've attached some xrays I took today of my patient "John Doe" ;) and will explain what everything is.
000 - Dual USB charger pack
001 - Ethernet cable and an old style 30-pin iPhone cable
002 - iPhone 5C (plastic case) lightning port area
003 - iPhone 4S (metal cased) old style 30-pin iPhone port area
004 - Casio W-96H digital watch
These were taken with phosphor plates... Not the digital sensor. And subsequently scanned into the system. There was no change in contrast/balance/intensity done... Just straight off using dental settings. Took about 3 minutes to do.
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Last image... sorry was over 2MB max attachment to a post.
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James_s, maybe your state is one of the lenient ones. It is regulated at the state level here. I checked Ebay again after your earlier post and the vendors I checked had a note at the bottom saying they would require evidence of licensing in states and countries that required it. I haven't actually tried to buy anything to see if they mean it, but my state is one that does restrict things.
edy - the small electronic heads might not be too big an issue if you use one of the programs that stitches images together automatically. Some of the fancy dental machines have that feature built in, generating a strip covering the whole mouth in one image from all of those bite plate images. Two free ones are autostitch and hugein. I use autostitch and find it pretty easy although it is not a user friendly program. Many swear by hugein, but I haven't broken the code to get useful results from it.
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Oh the auctions all say that, it's a liability thing to cover the seller's butt, I'd bet money they never actually check with anyone.
The same is true for refrigeration supplies, once I took the trouble to get certified nobody has ever actually asked me for my refrigeration tech license.
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As I said, it may be a state based thing. I don't have a refrigeration license, and have been stopped from buying supplies. So they do check, at least in some places.
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Thank you all. I will dig through your answers.
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James_S:
very nice radiographies.
I particularly like the one with the box of light bulbs....pretty artistic.
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I really envy you guys that have unregulated X-Ray ownership.
Here to even buy one, broken or not, requires a radiation license. Used XRay gear goes to E-Waste or most likely landfill on a destruction order.
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I really envy you guys that have unregulated X-Ray ownership.
Here to even buy one, broken or not, requires a radiation license. Used XRay gear goes to E-Waste or most likely landfill on a destruction order.
First they came for your guns, but nobody said anything, because you're not a bunch of violent American cowboys.
Then they came for your X-ray machines, but nobody said anything, because, hey, X-ray machines are dangerous.
Then they came for your blue-ringed octopuses, your Irukandji jellyfish, and your funnel-web spiders, but.... nope, you can keep those. :-DD
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Enjoy it while you can, before everything fun gets banned, in the name of safety of course. As much as we claim to value our freedom, various things are outlawed or regulated on a constant basis and it's extremely rare for anything to ever be un-banned.
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Modern x-ray machines are safe enough to be operated without shielding. Vets don't shield themselves heavily anymore when taking x-ray photos for pets. Sometimes they just hold the animal on one end when taking x-ray on the other end.
Modern (read: advanced, expensive) vet clinic use x-ray machines emit high power x-ray in very short bursts so that it is enough to excite digital x-ray sensor plate, while total energy is very low, almost negligible even if used everyday.
Also, modern x-ray tubes use microfocus design so the emitter size is very small, hence very small focal point size. This also allows better image quality at lower total energy level, which also protects operator.
This is all true. My warning was related to this x-ray tube which is sold by some russian seller on ebay. It is a nice piece. But dangerous!
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Most machines and components accessible to the hobbyist will be older, simpler units and most will require using film to take the image so potential exposure is much higher than a modern digital machine. With some care and common sense there is little risk but one does have to be careful. Even a little dental tube really can be dangerous. The heads are very well shielded though and at the power levels typical of these scatter is negligible more than a few feet away.
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I wonder how hard it is to get an X-ray technician licence? Do you need to pass an exam? It might look good on your CV. :)
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It doesn't get any more 'bench-top" than the set-up shown in the pic on that eBay advert.
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It doesn't get any more 'bench-top" than the set-up shown in the pic on that eBay advert.
That does look very dangerous though. I wouldn't want to be anywhere near that set up while it's running.
I presume the meter is the object being X-rayed and that white plate is a phosphor with the camera to take a photograph of it? I wonder how long the exposure time needs to be to get a good picture?
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Interesting picture.
Cold Cathode X-Ray tube with absolutely no shielding (not a great idea), Low resolution scintillator plate and a digital SLR with no X-Ray screening glass to protect the CCD chip.
Not a setup I would recommend to anyone..... why ?
1. That cold cathode tube was designed to sit inside the EHT transformer that was cooled with oil. The Oil acts as a coolant and X-Ray reduction device.
2. The scintillator plate is an image enhancer (intensifier screen) from a film type X-Ray plate. Quality and sensitivity can vary greatly. Resolution is usually not that great when used with a digital camera in the shown format..
3. The CCD imaging chip and associated electronics may be adversely effected by the X-Ray energy hitting them. This causes spotting on the image. If a CCD chip is in use, the exposure to X-Ray can permanently increase its dark current, causing the camera harm. It is better to use a 45 Degree mirror and image the intensifier screen with the camera out of the main X-Ray energy beam.
That is very much a Heath Robinson X-Ray imaging setup that should only be used with great experience of X-Ray energy and appropriate precautions. It would seriously fail the HSE regulations in the UK on many counts ;D It stands as an example of why real X-Ray equipment and tubes are licenced in some countries. In the UK we are a little more open minded though.
I became a licenced radiographer through my work and was suitably Harwell 'badged' for many years. I never had an abnormal dose reading in my career. Correctly configured equipment and use is the key to safe X-Ray imaging. Soft X-Ray is easily attenuated, but still harmful at high accumulated doses.
Like many things in life, X-Ray may be used safely, but abusers of such need to realise that damage to the skin, or worse can result.
Fraser
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I wonder how hard it is to get an X-ray technician licence? Do you need to pass an exam? It might look good on your CV. :)
Varies widely with location and application. Where I am the license to operate industrial equipment involves a few hundred dollars and a short course. Then periodic refresher training and renewal fees. Medical X-ray licensing is more involved.
I haven't looked into how transferable this is between jurisdictions, but suspect there is little ability to transfer.