X-Ray machines - Technology and use in Hobby Electronics. - Page 1
Forum section: electronics / testgear

author: Fraser
author_rank: Super Contributor
timestamp: November 29, 2014, 10:07:50 pm
content: QuestionIs an X-Ray machine useful for electronics or is it just a geek toy?AnswerThere is no simple answer as much depends upon the electronic engineer’s needs and experience.QuestionIs X-Ray safe to use?AnswerYes and No...... Yes if used correctly, no if misused. There is NO 'safe' dose of X-Ray radiation. Exposure to ionizing radiation should kept as low as possible and below the agreed safety thresholds for users of such equipment. Ionizing radiation can cause cell deformities, radiation burns and potentially cancer.Still interested? Then read on for more on this topic......1. What can an X-Ray machine offer the engineer? In short, the ability to see the unseen.An X-Ray machine of suitable power effectively makes solid objects transparent so that the user may see what resides within the DUT. Typical cases in electronics would be nondestructive visibility of hidden case screws and clips, hidden components within potting compound, internal parts within sealed modules and copper tracks within multi-layer PCB's or under IC's. In industry X-Ray is also used to inspect the quality of solder balls under BGA devices. This requires high magnification however. The only limitation on seeing through opaque objects with X-Ray is the power of the beam used as that and the imaged material density determines the penetration depth.2. What types of X-Ray equipment are available to the public?X-Ray is ionizing radiation that can cause harm to life, be it human or other. As such there are definite rules to be followed when using X-Ray producing equipment, even at low tube drive voltages. For this reason some thought is needed with regard to what X-Ray equipment is best used by the everyday user rather than a licenced industrial operator.a) Open site medical X-Ray and suspect package inspection equipment.Open site X-Ray can be dangerous as it requires the operator to ensure that no one, including themselves, is in the X-Ray beam or subject to high levels of reflected X-Ray energy. There is typically no physical containment of the area between the X-Ray generator, the DUT and the imaging system. As such it is possible for irradiation to occur if used incorrectly. There are significant legal implications if a person believes that they were irradiated by the user of the equipment. Examples of this type of equipment are: Dental X-Ray heads, Golden X-Ray inspection X-Ray generators and LIXI Scope medical triage X-Ray used for fast limb damage assessments.b) Controlled space X-Ray equipment.A classic example of a controlled space X-Ray is a Hospital X-Ray facility where health and safety measures are built in to the room design and protective screens are present for the operator. Such facilities may still contain exposed X-Ray generators but their activation occurs at a safe distance and targeting is carefully monitored throughout the imaging process. The processes and controls make such equipment safer to use than open site X-Ray. To a degree, dental X-Ray may be similar but the Generator heads can be free floating for flexibility of use. This is where the risk of unintentional irradiation lies.c) Cabinet X-Ray equipmentCabinet X-Ray equipment is likely to be the safest of the available X-Ray imaging options as the controlled space is reduced to the area directly around the Generator, DUT and imaging system. Provided the cabinet is not damaged there is no reason for X-Ray to escape its confines and so the risk of irradiation is minimal. Cabinet systems often do not require the operator to be licenced or X-Ray dose monitored. This is in recognition of their intrinsic safety. Common cabinet type X-Ray equipment’s are X-Ray Mail scanners and medical biopsy/research X-Ray equipment. A semi cabinet equipment known to most of us is the conveyor belt baggage scanners found at airports etc. These are still intrinsically safe when used correctly but a fool may still irradiate parts of their body that are passed into the 'tunnel' whilst the X-Ray Generator is activated. This makes it less safe than a full cabinet design but process mitigates the risk adequately.d) Home built X-Ray equipmentHome built X-Ray generators have the potential to be lethal and very unsafe for the user. Before considering building an X-Ray Generator or such equipment, the wise DIY enthusiast ensures that they are in possession of adequate safety knowledge and design principles. The risks are not just in containment of the emitted X-Ray but also the high voltages and currents associated with common X-Ray tubes. Death or serious injury can result from a poorly built X-Ray Generator. Not a DIY project that I can recommend for the beginner entering into the world of X-Ray imaging. The builder must build a safe EHT power supply, contain and cool the X-Ray tube, Shape the X-Ray beam, control the output power and screen the user from X-Ray, both on beam and reflected.3. Are there different types of X-Ray?Yes there are two major types of X-Ray energy. Soft and Hard. Soft X-Ray is produced at low anode voltages such as 10KV. The X-Ray beam has very low penetration capability and that may make people think it safer than Hard X-Ray. This is not the case however. Remember there is no 'safe' dose of ionizing radiation. Soft X-Ray is stopped as it passes through human or animal tissues. It is totally absorbed by the tissues cells with potential damaging effects on them. Soft X-Ray is not great for imaging even low density DUT's and is often filtered out using an Aluminium plate in Medical X-Ray equipment. It provides no image enhancement yet increases the patients X-Ray dose significantly. Do not think of soft X-Ray as 'Safe' even at lower levels of power. Hard X-Ray is produced at higher anode voltages of say 25kV and above. The anode of large medical X-Ray equipment’s often uses anode voltages of more than 120kV. Hard X-Ray tends to punch through human tissue with less potential harm to the cells than soft X-Ray. Hard X-Ray provides the images that we know and love at airport security etc. It punches through many different densities of DUT depending upon the Anode voltage that is being used.4. What specifications are important when looking for an X-Ray machine?Much will depend upon your intended uses for the unit but here are some comments:a) Open, controlled space or cabinet solution. I recommend a cabinet solution for reasons of intrinsic safety and often no need for X-ray dosimeter monitoring by your national radiological service.b) X-Ray Tube types. There are different X-Ray tube types for different applications. There needs and performance differs. Conventional X-Ray rubes operate at high anode voltages and the target has a relatively large spot size. Such tubes are not great doe high resolution imaging. Micro-focus tubes normally operate at lower anode voltages of less than 100KV and so beam penetration is often inferior to that of conventional X-Ray tubes. More KV = more penetration. They have a very small target spot size which provides excellent high resolution imaging. To protect the target Micro-focus tubes may have low operating currents. Do not be tempted to increase the current above the manufacturer’s specification. Damage will result. Like many things in life there can be a choice between brute force with deep penetration and precision directed energy with less penetration. The choice is often dependent upon the user’s needs. In the case of a baggage X-Ray machine, high resolution comes second to penetration capability to see through various dense materials such as metal cans etc. A biopsy medical X-Ray needs a more delicate touch with lower need for penetration but great need for image resolution and clarity. This is why a biopsy X-Ray runs a Micro-focus tube and high resolution diode array camera.5. What penetration can be expected of conventional and Micro-focus X-Ray tubes?Penetration is very dependent upon the DUT material density, KeV of the X-Ray beam and the sensitivity of the imaging system behind the DUT. as a very rough idea of what to expect. A conventional >120KV X-Ray generator can provide good penetration in many metals such as aluminium, steel, copper, brass etc. Higher KV is needs for higher density materials. Micro-focus tubes run at <100KV and this limits their penetration capability. Do not expect good penetration in steel or brass. Penetration in less dense metals such as aluminium and copper is good. Baggage X-Ray machines with image enhancement fitted can image through 25mm of steel! A 35KV Micro-focus cannot image through 2mm of steel. Very much horses for courses.6. What X-Ray imaging systems exist and which is best for the hobbyist user?Conventional X-Ray imaging uses X-Ray sensitive fil that is sandwiched between scintillator plates in a cassette of varying sizes. The Film reacts to X-Ray exposure and the scintillator plates produce visible light that enhances the image produced. High resolution images use just the X-Ray sensitive film as the result is a crisper image. The problem with the film type imaging is the need to develop it much like conventional film. Not very hobbyist friendly. A scintillator plate behaves like the film in that it produces an image but is exists only whilst the X-Ray is present on its surface. Polaroid used to produce film cassettes that contained a scintillator plats that illuminated a monochrome instant film. The exposed film was processed in the same way as conventional Polaroid instant film. Such a system was simple but expensive to use. Now pretty much obsolete. New technologies have developed. Scintillator plates are still in use but they are now viewed by optical cameras and high resolution diode array detectors. The digital age has come to X-Ray imaging. A digital cassette is now used that contains the imaging array and all electronics to store the array output. A dedicated machine then downloads the data from the cassette for processing. Such a system is very expensive and not normally suitable for the hobbyist. I recommend using a scintillator plate with digital camera or diode array imaging technique. It offers many benefits to the hobbyist. Even a Digital SLR on a slow shutter can produce images from a scintillator plate. Scintillator plates may be purchased on ebay or medical X-Ray film cassettes may be purchased and the two scintillator plates removed from them.7. What did I buy and from where?I have regular access to an industrial X-Ray machine. Sadly I will lose access to such equipment when I take early retirement in February 2015. I wanted to find a basic X-Ray imaging system that would allow me to see concealed screws and clips in equipment cases, components concealed in potting and also PCB tracks inside PCB's. I do a lot of PCB reverse engineering and multi-layer PCB's have always been a challenge. I also fancy doing some artistic X-Ray work..... Ever seen an insect or flower in the X-Ray image domain? It can be interesting to play with such if the equipment is capable of high resolution images.I decided that a compromise solution that might just be adequate for my needs was a Todd Research or similar X-Ray mail scanner. The resolution is lacking but penetration is pretty good. The common use of a relatively low resolution optical camera viewing a scintillator plate limits performance. The higher levels of X-Ray that these machines produce does have an issue for many users..... The equipment makes use of much lead shielding and so they are VERY heavy to transport and move around the lab. Definitely not portable equipment.By chance whilst on ebay I stumbled upon a medical X-Ray cabinet solution that is designed for Biopsy and even electronics imaging. The unit is called a Faxitron MX-20 and utilizes a 50KV micro-focus X-Ray tube and a sensitive diode array digital camera that drives a dedicated imaging card in a PC running Windows 2000 Pro. The tube is only run at a maximum of 35KV which does limit penetration but the high resolution imaging and digital image capture capability won me over. Penetration is not always the most important specification. An added benefit of the MX-20 is that it is intrinsically safe to use and its low KV on the Tube Anode reduced the need for screening. The MX-20 needs only a twin skin steel case to contain the ionizing radiation. No lead shielding means that it is relatively light at 70Kg. The MX-20 comes in two major versions. Conventional film/digital cassette and high resolution digital camera array. Sub versions of the Digital camera equipped unit provide different diode array sizes to suit the intended task and cost constraints of the customer. I purchased two Faxitron MX-20 units, one is without the digital imaging capability and the other is equipped with the full Monty 2048 x 2048 pixel 100mm x 100mm high resolution diode array camera. Both units use the identical X-Ray generator that forms the top 4 inches of the cabinet and is removable. If the digital MX-20 suffers a tube or EHT failure I will just transplant the other unit’s top section onto the digital cabinet. I should have a decent X-Ray capability for many years to come.Another owner of an MX-20 (Digital) was without the required PC and interface card. He decided to reverse engineer the unit in an attempt to extract imaging from the camera. He has a web page showing some internal images of the MX-20 that I hope you will find interesting.http://photonics.engr.uga.edu/xray_imager/index.htmlI will not repeat the images here as the web pages are an interesting read. The Faxitron is a lovely piece of kit that is well suited to X-Ray imaging of microelectronics but it does not have the penetration to image through steel screening cans.So is an X-Ray machine a necessity in the modern electronics lab or workshop or just a Geek toy? In my opinion it is neither. For those with a need for seeing inside sealed or potted items, it can be invaluable. Reverse engineering is also assisted by such technology as hidden traces become clearly visible. Is it a toy.... no, definitely not a toy as it has safety implications and is not very geeky toy like anyway. As Mike has said in communications over these units.... they are a nice to have rather than a necessity. I agree but recommend that if, like me, you stumble upon a suitable system, you consider buying it.For information my Faxitron MX-20 cabinet is a 2005 unit that is still around in many bio labs around the world. It cost $22,000 for the cabinet and an extra $25,000 for the digital camera imaging option (inc computer, interface and software).http://www.faxitron.com/life-sciences-ndt/products/mx-20.htmlI paid GBP250 for the standard film MX-20 and GBP1000 for the Digital Camera equipped MX-20 unit that included all hardware, P4 3GHz ASUS computer, interface, software and LCD 17" monitor. Not an insignificant sum, but well worth the investment for me in my electronic activities.I shall upload some images in due course and will be happy to answer questions on X-Ray technology.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: November 29, 2014, 10:08:54 pm
content: Faxitron MX-20 images

author: Fraser
author_rank: Super Contributor
timestamp: November 29, 2014, 10:09:19 pm
content: Faxitron MX-20 images

author: Precipice
author_rank: Frequent Contributor
timestamp: November 29, 2014, 10:31:00 pm
content: That's quite wonderful, and I'm envious! I've been accumulating parts for a homebuild (PSU, emitting valve, since I'm in no great hurry, scintillation film, and because of jobs I've done, I've got a lot of HD CMOS camera chips that I can crack the glass off and press bits of film onto, to see if direct coupling is possible, for high res work).(I take it your prices on the MX-20 stuff weren't repeatable? I'd abandon homebuilt like a shot, for that price!)Is there any chance of a slanted shot to show some BGA balls and their soldering?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 29, 2014, 10:50:53 pm
content: Wish I had the space and money to tinker around with stuff like this. When I wanted a piece x-rayed, I sent it off to a lab.

author: Fraser
author_rank: Super Contributor
timestamp: November 29, 2014, 10:51:28 pm
content: @precipice,Sadly the two units I purchased were the only ones the sellers had. Different sellers but both local to me. It was just meant to beBoth sellers said they have had the MX-20 before but most come with no hard disk due to DPA. You now know someone with a copy of the software thoughKeep an eye out on ebay.co.uk and DOT Med. The sellers are dealers in ex lab and hospital equipment that they buy from auctions around the country. Having looked at the Win2000 event logs my unit has had very little use since 2005. 30 or so days of use !Prior to this purchase I was considering building a simple X-Ray source and, like you, bought the required main parts. I bought some BS7W low voltage X-Ray tubes from Ukraine and some scinterllator plates from Russia. The BS7W is an interesting tube that only requires 15KV across it to produce decent X-Ray output. Take a look here if you are not already aware of this tube:http://www.hardhack.org.au/xraydtthttp://www.hardhack.org.au/crystallographyThe beam has a 5 degree divergence upon exit from the tube target. Sounds about right for very small images such as in X-Ray Microscopy, or larger images if the DUT is placed around 1m from the tube !I bought a pair at around GBP50 each as they will become unobtainium once the sellers stock is exhausted. They are far easier to use than a conventional high voltage tube and have better output than an old TV EHT rectifier valve. I may sell my BS7-W's if anyone wants them as my Faxitron will serve my needs fine.Aurora

author: IanB
author_rank: Super Contributor
timestamp: November 29, 2014, 10:53:12 pm
content: When you say "not an insignificant sum", are you referring to the £250? If so, I am surprised. That seems to me a like the kind of sum you might spend on an electronic toy like a camera or a computer. It doesn't seem like a heavy sum.I did a quick scan of your introductory post, but I didn't immediately see the answer to a question many may have. Could X-rays damage the item being imaged? Like for instance, could they induce voltages in delicate circuits or corrupt flash memory data?

author: Fraser
author_rank: Super Contributor
timestamp: November 29, 2014, 11:17:32 pm
content: @IanB,I was referring to the cost of the Digital MX-20 at GBP1000. It is true that I can afford such a price, but hobbyists budgets can be limited and I made the statement in recognition of suchI personally consider my purchases to be bargains and I am a very happy bunnyWith regard to damaging electronics with X-Ray, I can make the following real world comments1. In production quality control and inspection it is not unusual to find a specilaist microfocus X-Ray machine that is capable of in excess of 200 KV across the the cathode & anode. These machines are used to inspect the balls on BGA chips for presence, poor shape, cracking and bridging. I have seen sensitive BGA chips inspected at in excess of 160KV and no damage has been considered likely.2. I personally have inspected sensitive electronic equipment, including high speed computers, with pulsed X-Ray with an output of up to 300KeV. I have yet to induce a fault in such equipment.3. X-Ray imaging is not advisable on electronics that is powered and operating. That is just common sense.4. Never X-Ray in an explosive atmosphere !5. I believe much testing has been done on sensitive memory chips to determine the damage level for memory cells. I have no doubt that corruption could occur with very high levels of X-Ray passing through the die but I have not seen it in my 27 year career in the field. Airport X-Ray should not corrupt memory cells and the fact that all laptops get X-Rayed these days at airports suggests that this is indeed the case.6. I HAVE seen an electret microphone destroyed by significant and repetitive exposure to X-Ray of around 160KeV. The static charge was removed from the plate and so it was no longer an electret mic.The Mic was tested around 20 times at approx 120 to 160KeV. That is pretty high levels of exposure !So have I personally seen ANY evidence of damage to memory cells or sensitive microprocessors by normal X-Ray imaging. Nope no sign of any issues at all. I am not saying that you cannot damage such devices with X-Ray but I suspect the KeV would have to be very high to do so. HOWEVER, anything that holds a static charge is succeptible to damage. Old 'Stephen' radiation monitors use a static charged Quartz filament as the radiation detector. The ionizing radiation discharges the charge on the filament in a predictable manner and this gives the dose reading over time.Do I have any worries about 35KV tube anode X-Ray illumination of a sensitive chip... no concern at all. 160KV anode voltage...I am still not concerned about damage.Aurora

author: IanB
author_rank: Super Contributor
timestamp: November 29, 2014, 11:21:12 pm
content: Quote from: Aurora on November 29, 2014, 11:17:32 pmOh, I missed the £1000 bit. My mistakeYou are correct, that starts to become a significant sum...

author: ixfd64
author_rank: Frequent Contributor
timestamp: November 29, 2014, 11:26:32 pm
content: Interesting "patients" you've got there.

author: Fraser
author_rank: Super Contributor
timestamp: November 29, 2014, 11:28:23 pm
content: Ionizing Radiation damage to electronics is discussed here:http://www.erai.com/presentations/Training%20Track%206/Radiation%20Damage%20on%20Electronic%20Components-Creative%20Electron.pdfhttp://www.spansion.com/Support/Application%20Notes/X-ray_inspection_on_flash_AN.pdfThe Spansion comment on flash memory makes very interesting reading. It would appear that X-Ray below 9KeV is more damaging to the memory cell charge than higher KeV levels.Aurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 30, 2014, 12:12:41 am
content: Something that in my (brief research) a while ago wasn't clear. Obviously this is very country dependent, but in the UK what are the legalites of using X-ray equipment?As far as I could establish (UK) :There don't appear to be any restrictions on ownership of x-ray equipment, nor any system for registration - ISTR reading that in some countries (US? Canada?) all x-ray kit must (in theory) be registered and any transfer notified. The place I got the baggage X-ray from, who regularly deals with this stuff, was quite keen to take a note of the generator serial number and the purchaser's address - I don't recall if he asked for a disclaimer.Use in conjunction with a business or where there are employees comes under the Ionising radiations Regulations 1999. What is not clear is whether any aspects of this apply in a hobbyist scenario - The regs make frequent use of the term "employer" but I couldn't make out if this meant in a workplace context or as in "employing ionising radiation"Is there any distinction/exemption between open sources (e.g. medical/dental) and closed ones (mailroom, baggage etc.)?Of course the no.1 thing is to try to keep under the radar.. I know that at least one UK amateur x-rayer had a visit from someone - all was OK in that case, but was just wondering what the actual legal position was.Incidentally Ben Krasnow got some heat from his homemade CT and backscatter setups, but again they seem to have taken a pragmatic approach, last reported as "Don't use it til it's all shielded and we'll come along & certify it for you"

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 30, 2014, 12:16:50 am
content: BTW on teh subject of x-ray effect on electronics, this is an interesting appnote on the effects on Intersil's voltage reference devices that use an analogue floating gatewww.intersil.com/data/an/an1533.pdf

author: EEVblog
author_rank: Unknown
timestamp: November 30, 2014, 01:27:10 am
content: 2nd hand units of any decent capability (these days that means digital output) are rare as hens teeth here in Australia.

author: Fraser
author_rank: Super Contributor
timestamp: November 30, 2014, 01:37:32 am
content: @Mike,A good question and one that I cannot answer except to provide the following comment:1. Any employer who requires staff to usenon(ooops!) ionising radiation is duty bound under law to protect those employees from harm. As such the employer must have a nominated non ionising radiation adviser available. That person must attend a training course at what was NRPB (UK). The employer is also required to detail the equipment that will be used by the employees. Some equipment is intrinsically safe with screening and interlocks etc, some is open site and considered potentially harmful. In the case of intrinsically safe equipment such as mail room scanners, the employer DOES NOT need to have the employees Dosimeter badged but the machine must be inspected for leakage on an annual basis by a qualified person. This is often the service company that supports the equipment. Equipment that produces open site X-Ray or that is very powerful in nature invokes user monitoring regulations where the users are dosimeter badged and given annual health checks by a doctor. I came under that heading and my annual radiation dose was carefully monitored. I even had to take my badge with me when being X-Rayed in Hospital. What was NRPB (I forget what it calls itself now) provides advice to employers and employees on Radiation related matters. Harwell run the dosimeter monitoring service.2. The ownership of an electric X-Ray producing equipment is legal in the UK without registration. Manufacturers are VERY careful about who has access to X-Ray machines as they are concerned regarding liability in the case of an accident. We used to place Mail Scanners beyond easy use by cutting the mains cable and removing the control boards. These days the manufacturer insists on removing the X-Ray generator and sending it for correct disposal. This may be to avoid amateur tinkering with what is after all a dangerous piece of equipment if used improperly. It is not radioactive waste.3. Ownership of Radioactive isotopes, as used in some X-Ray appliances such as the Lixi Scope is a complicated matter. The isotopes, though small, must be transported in line with all manner of regulations and packing requirements. The Iodine isotope has a half life of only 6 months so the user must arrange for replacement at regular intervals via approved means.That is GBP5000 a time ! Ownership of a radioactive isotope is not recommended outside accepted institutions as there is fear of dirty IED's these days. I recommend against buying ANYTHING that states that it contains a radioactive isotope. Some are VERY nasty indeed. The only exception would be ionising chamber fire detectors but they are less common these days anyway.4. Is it legal to use an intrinsically safe X-Ray cabinet as a hobbyist ? I honestly have no idea but common sense makes me think that provided it has not been modified and is being used only by the owner in accordance with the manufacturers instructions, there should not be a problem. In my case I have teh advantage of having been officially trained in non ionizing radiation and its hazards. As such I am less likely to do something daftMy unit runs with a maximum voltage across the X-Ray tube of 35KVp. The penetration capability of the KeV that it produces is so low as to be easily attenuated by my garage walls and doors. Fall off with distance also means that I am not able to irradiate my neighbours even if I wanted to ! Now if I owned a much more powerful Industrial X-Ray machine that could produce significant KeV, I would be nervous on two counts. 1. Am I safe from its emissions. 2. Am I breaking any laws by using it without regular site checks and formal Non ionizing radiation surveys ?5. Equipment that is not legal to use is normally placed beyond use by the service agents when it is decommissioned. I see no evidence of such activity with low output X-Ray systems that are often seen for sale, but then maybe, just like us, no one really knows the law surrounding ownership and use of such equipment as part of a hobby.6. Those thinking of experimenting with X-Ray do need to consider the legalities of such in their country. As Mike states, if you are sensible you will probably be OK but remember that Non Ionizing radiation is not healthy for you or others so health and safety organisations can get a bit worried about DIY equipment ! BE WARNED Guiger Muller tube based non ionizing radiation meters do not have a linear response to X-Ray and most do not provide a useful reading below around 40KeV. They are counters so if they do not trigger on say 35KeV you will be unaware of a risk ! Scintillator based meters are required for lower KeV's.Aurora

author: amyk
author_rank: Super Contributor
timestamp: November 30, 2014, 01:49:19 am
content: You mean ionising and not non-ionising, right?Becausealmost everyone probably already owns a very powerful non-ionising radiation device.

author: Fraser
author_rank: Super Contributor
timestamp: November 30, 2014, 01:54:10 am
content: Mike hasn't mentioned it but he did an excellent tear down of a mail scanner a while ago.That is a more powerful unit than mine as it has to punch through all manner of objects and is used by staff so fine tuning of images if not an option in many cases.The unit appears to be a Todd Research model as its internals look familiar to me. As you will see, it uses a cctv like camera technology that is viewing the Scinterllator plate. This was a technology that appealed as it was cheaper than large diode detector arrays and associated processing.Mike's unit was the sort of thing I was hunting for when I found the Faxitron MX-20. In the end the MX-20 suits my needs better.For those thinking of experimenting with X-Ray imaging using a CMOS or CCD camera, be aware taht you need a lead glass plate in front of the imaging chip or camera lens in order to avoid 'sparklies' caused by the X-Ray beam hitting the sensitive detectors on the chip. Remember, X-Rays are Photon based !Aurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 30, 2014, 01:54:48 am
content: Quote from: EEVblog on November 30, 2014, 01:27:10 amDigital stuff is rare and expensive everywhere unless you are extremely lucky like Aurora, but the combination of a DSLR and a screen can be a reasonable substitute to avoid messy film processing.QuoteSurely X-rays are ionising radiation...?QuoteBut best to remove any radiation warning stickers before carting the lead off to the scrappie to avoid them getting spooked..And probably not a good idea to chuck a beryllium windowed tube in the bin...

author: Fraser
author_rank: Super Contributor
timestamp: November 30, 2014, 01:59:20 am
content: Its late and brain is fading....yep I meant Ionising and not non-ionisingHowever I have used some pretty scary NON-Ionising radiation emitters as wellRadar isn't too healthy if misused.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 30, 2014, 01:59:51 am
content: Quote from: Aurora on November 30, 2014, 01:54:10 amOr use a mirror, as in the mailroom unit.Another option may be to point the camera at the plate from the same side as the x-ray, so you're not getting x-rays directed at the camera.Incidentally there is another type of detector I've seen a couple of types of on ebay, which exposes a "magic" storage screen material, and then afterwards scans it using a red (I think) laser and photomultiplier to read out the latent image.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 30, 2014, 02:12:46 am
content: Quote from: EEVblog on November 30, 2014, 01:27:10 amAnd it appears you'd need a license...http://www.health.vic.gov.au/radiation/businesses.htmThough there are a few dental units on Oz Ebay

author: Fraser
author_rank: Super Contributor
timestamp: November 30, 2014, 02:25:54 am
content: In case anyone in the UK wants to read the HSE regs, they are to be found here:http://www.legislation.gov.uk/uksi/1999/3232/contents/madeI also found the dental regulations for dentists but it basically said to comply with the above regs.https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/337178/misc_pub_DentalGuidanceNotes.pdfI comply on the X-Ray containment, interlocks, key control and access control so I believe I pass the basic requirements of use. I am not about to employ anybody or run demonstrations to visitors so my conscience is clearAurora

author: Fraser
author_rank: Super Contributor
timestamp: November 30, 2014, 02:52:32 am
content: I briefly mentioned the issues surrounding radioactive isotopes used for X-Ray and medical therapies.Some time ago I read of a stolen isotope that ended up contaminating 100's of people and killing four. Its a very nasty example of how dangerous certain isotopes can be:http://en.wikipedia.org/wiki/Goi%C3%A2nia_accidentIf it says Isotope.....walk away.If its a large dew drop shaped steel object on a strong stand and the 'window' is open........ run away as quickly and as far as you canSuch units contain powerful (deadly) X-Ray source Isotopes for imaging thick steel as found in oil rig production. I remember a company went bust and when the owners of the industrial unit arrived to regain possession they got more than they bargained for. The defunct company used a large isotope for X-Ray work on steel tubes. It was still in the unit sat awaiting some poor fool to open its exit window. Fortunately someone recognised it. The bill for its disposal was massive as specialist facilities are needed to extract and store the isotope.Aurora

author: IanB
author_rank: Super Contributor
timestamp: November 30, 2014, 03:01:37 am
content: Quote from: Aurora on November 30, 2014, 02:52:32 amNah, you just give it to the NNL at Sellafield and say "Here you go chaps, your problem!"What are they going to do, give it back and say "No, thank you"?

author: Fraser
author_rank: Super Contributor
timestamp: November 30, 2014, 03:09:20 am
content: Sadly no one does anything for nothing in the UK these days....they would just send you the fat bill and pursue you for its payment to the grave

author: Fraser
author_rank: Super Contributor
timestamp: November 30, 2014, 03:54:45 am
content: Regarding damage to flash memory caused by X-Ray exposure, I have just read a post by 'Psi' on the topic. From what he says it appears unlikely that damage will occur to flash memory with normal exposure to airport type X-Ray units etc.https://www.eevblog.com/forum/chat/x-ray-machine-resources/msg57212/#msg57212Aurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 30, 2014, 10:09:54 am
content: Quote from: Aurora on November 30, 2014, 03:09:20 am..which is why we have so much fly-tipping.

author: German_EE
author_rank: Super Contributor
timestamp: November 30, 2014, 10:52:23 am
content: In decades of electrical engineering (plus some electronics on the side) I have only once needed something x-raying. In this case I just went to the local vet with a six-pack of his favorite beer, a man who had the right equipment and the knowledge of how to use it.

author: SeanB
author_rank: Super Contributor
timestamp: November 30, 2014, 10:58:16 am
content: Quote from: German_EE on November 30, 2014, 10:52:23 amAnd I would bet he was happy, as there was no sharp teeth attached to the one end looking for his arm when he stuck a thermometer in.Like the guy with a sheepdog, who had just bitten him, so he had a dog biscuit out so he would know which end to boot.

author: HighVoltage
author_rank: Super Contributor
timestamp: November 30, 2014, 12:10:24 pm
content: What a great topic.I wish also to have an x-ray machine in my lab.Every time I need something X-Rayed, I go to my dentist.Here is a picture attached of a high voltage connector, embedded in a hard epoxy resin potting.This was done a modern digital X-Ray machine at a dental office here in Germany.The X-Ray machine is made by Sirona

author: timb
author_rank: Super Contributor
timestamp: November 30, 2014, 12:30:22 pm
content: I just hide the circuit in my mouth when I go to the dentist. It's like a 2-for-1! Unfortunately I had to get a Wisdom Cap pulled last time.If it's too big to fit in my mouth I just make my dog eat it and it's off to the vet!Sent from my Tablet

author: Precipice
author_rank: Frequent Contributor
timestamp: November 30, 2014, 01:02:24 pm
content: Quote from: Aurora on November 29, 2014, 10:51:28 pmI'd certainly be interested in those tubes! (at the moment, all I've got is a 6VS-1, and these look a lot more convenient).

author: ovnr
author_rank: Frequent Contributor
timestamp: November 30, 2014, 01:05:03 pm
content: Incidentally, I've got a Trixell Pixium 4700 5-megapixel FPD sitting here. It does 2480 x 1910 at up to 7.5 fps with 154µm pixels.I was somewhat surprised by the fact that it only has optical interfaces - four slow ones (RX/TX/sync) and a ~1gbps high-speed data link. The only other connector is a DB9 for power; it takes 24V @ 5A, and is liquid cooled.If any of you nutcases want it, make me an offer.(It was pulled from working equipment - I should do a writeup of my teardown of that.)

author: MadTux
author_rank: Frequent Contributor
timestamp: November 30, 2014, 01:06:56 pm
content: It's all about having a diode array xray detector or any other reasonably sensitive digital xray detector. You can work with small beam currents and still get beautiful pictures, 300uA @ 35kV =>12W beam power, lol.Small beam current also produces a small focal spot and therby sharp images, since you only need a small filament and get no overheated/melted spot on anode.A while ago, I also played around with a experimental xray setup, but quickly decided that I better stop until I get good lead shielding, since my old polish DP-66 geiger counter clicked madly from backscatter.The tube was behind more than 5cm of lead blocks, so no direct xray hit me, only the backscatter from the wall. Unfortunately I somehow got really bad xray intensifying screens that failed to glow even when directly in front of the tube. A movie camera that was placed in front of it showed "snow storm" as the HV was switched on. ZnS doped glow in the dark plastics also glowed quite nicely.HV supply consisted of a HP 6274 PSU that was connected to a Mazzilli driver on a homemade flyback transformer. Output went into a Cockcroft–Walton multiplier that finally generated around 100kV DC at a few mA max.Does anyone btw know a document scanner that only needs small amounts of light? I thought about converting normal scanners into xray detectors by placing an intensifying screen on top of it and disconnecting the power of the LEDs or CCFD that usually iluminate the document. In theory this setup should have much better light collecting capabilities and is much smaller than the long exposure DSLR setups that are usually used. Furthermore there's no barrel distortion caused by uneven distance from camera lens that has to be corrected in GIMP. Xray noise could be eliminated by running multiple scans and ANDing the reults.The Canon N670 (cheap crap scanner) that I tested for that purpose had really bad ISO sensitivity (tested by placing multiple layers of newspaper between scanner and flashlight), so bad that I doubt it could pick up any light from a intensifying screen.

author: Fraser
author_rank: Super Contributor
timestamp: November 30, 2014, 01:34:09 pm
content: As has been stated, an X-Ray machine is not an essential in the modern electronics lab but it is nice to have the capability and I am a self confessed imaging technology geek !My MX-20 likely cannot inspect BGA balls as its only a baby in terms of KeV. I will do some images of chips to see what it can cope with.I have used X-Ray for non destructive testing and investigations into electronics buried within potting. It helps to know where the components are located. I have used X-Ray recently to identify the components used in my very rare and expensive HP LogicDart logic analysers.I was a regular user of X-Ray equipment so for me it is little different to owning a microscope or thermal camera..... Right tool for the job, that's is my MO.What do you do when you can't tear it apart?....... X-Ray it !Aurora

author: Fraser
author_rank: Super Contributor
timestamp: November 30, 2014, 01:39:30 pm
content: @Precipice,I have two brand new BS7-W tubes. You can still buy them from Ukraine but Customs charge TAX & VAT. I will contact you via PM to discuss a mutually acceptable price I am happy to break even on the non Tax eBay price or even take a bit of a loss as I am unlikely to use these lovely little tubes.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: December 11, 2014, 12:32:01 am
content: I was asked by several people reading this thread about selling my two new BS7-W 15KV X-Ray tubes. I no longer need them as I have the Faxitron units. The original sale of these stalled so anyone who still wants them, please PM me and I will see if we can do business. To remind those interested, these are small heated cathode X-Ray tubes with an axial X-Ray output and tungsten target, from the MYR-2/4 system. They produce a controlled beam of X-Ray when 15KV is applied to them. Beam divergence is specified as 5 degrees and they may be run in continuous mode (not pulsed like some) from a common CCFL HV inverter with additional voltage multiplier stage for 15KV output. I am still tempted to keep them as they would make a decent controllable X-Ray test source or X-Ray microscope (which is what they were designed for). I would like to see them used rather than them sit in my spares boxes though.These are far more refined than using (abusing) a diode valve and the beam is controlled rather than a spray of X-Ray that occurs around a diode valve.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: December 11, 2014, 07:15:14 pm
content: Tubes have now found a new deserving home. Apparently they are very special tubes that are perfect for X-Ray crystallography.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: December 22, 2014, 08:42:51 pm
content: For those wondering what an X-Ray machine is used for in the electronics production industry, PACE manufacture the XR3000 inspection system. I was surprised to see that it uses only a 50kV tube to do its work. Lead is a significant attenuator of X-Ray yet a 50kV tube is obviously enough to see inside BGA solder balls.Manual is here:http://diagramasde.com/diagramas/otros/XR3000_En.pdfhttp://competence.com.mx/prods/pace/html/_ShowSystemDetails-5121.htmlIt costs $57000My Faxitron MX-20 is fitted with a higher specification (smaller spot size) 50kV tubeand a more sophisticated imaging arrayHaving briefly looked at BGA chip solder balls, I can certainly see their shape and alignment, possibly even voids within them.I am fortunate enough to have been gifted another, more powerful, X-Ray machine. Its an 80kVp cabinet X-Ray unit with digital imaging. It will be delivered after Christmas so I will hopefully have enough power in that unit if the Faxitron can't cope with solder balls.If people in the UK need something X-Ray imaged I may be able to help. Watch this space.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: January 12, 2015, 07:45:13 pm
content: Mike has bought a Faxitron nowHe has done a teardown and created a thread here:https://www.eevblog.com/forum/reviews/faxitron-mx-20-x-ray-system-teardown/msg585230/#msg585230Aurora

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: January 13, 2015, 09:55:24 pm
content: Quote from: Aurora on November 30, 2014, 01:34:09 pmI know nothing about X-Ray machines, so I'm probably wrong on this, but can't you just increase the exposure time penetrate the chip, or is the penetration capability of a machine solely due to the energy of the X-RAYs?

author: Fraser
author_rank: Super Contributor
timestamp: January 13, 2015, 10:25:28 pm
content: X-Rays have photonvelocitiesenergies proportional to the tube acceleration voltage (kVp). The higher thevelocitiesenergies, the higher the penetration through dense materials. As a material becomes thicker or more dense it attenuates the beam that illuminates it. If no photons make it through the material, no image will be possible. the current drive in the tube does not influence the penetration distance through a material.In a classic case it may be found that 50 kVp will not produce an image through 3mm of aluminium plate but 120kVp will. In the case of high resolution imaging it is important to use the lowest possible kVp that achieves correct exposure as definition suffers as the acceleration voltage increases.It has been asked whether the 35kVp of the Faxitron may be exceeded through modification. The answer is not simple. The Faxitron MX-20 uses a 12 Watt tube rated at 50kVp max and 1mA max. It is air cooled in the MX-20 rather than in an oil bath. The variable output DC power supply has a range of 10kVp to 35kVp so that would need to be changed. It is feasible to increase the tube drive but then cabinet containment becomes a concern as the kVp (and so penetration) increases.Aurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 13, 2015, 10:29:33 pm
content: Quote from: Sal Ammoniac on January 13, 2015, 09:55:24 pmNot really - increasing exposure time gives you better signal to noise on rays that penetrate at least a little, hence you can just about get images through copper foil on PCBs, but 35kV just won't go through any serious distance of metal. I don't know the physics but I'd expect there are some exponential functions involved.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 13, 2015, 10:39:19 pm
content: An analogy is that if you compare x-rays to light, current is like brightness, and kVp like colour temperature.The output contains a range of wavelengths up to a limit determined by the kvp, the lower end being determined by tube material and other filtering ( aluminium is often used to filter out softer, longer wavelengths).Think of metal as a blue filter - light from even a really bright red-hot filament is not going to be visible though it, but a dim white-hot one will make it through easily

author: Fraser
author_rank: Super Contributor
timestamp: January 13, 2015, 10:42:08 pm
content: Some useful reading on the penetration of X-Rays may be found here:http://www.sprawls.org/ppmi2/RADPEN/

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: January 14, 2015, 03:19:41 am
content: Quote from: Aurora on January 13, 2015, 10:25:28 pmReally? I though that all photons have the same velocity, namely C. Perhaps you mean photon energies?

author: Fraser
author_rank: Super Contributor
timestamp: January 14, 2015, 03:37:23 am
content: Ooooops. Energies is the correct term as you say.Aurora

author: mete
author_rank: Newbie
timestamp: April 03, 2015, 07:28:22 pm
content: Hello everyone. I'm new here. Your topic is interesting. My question may be a little different then the title you are currently discussing. I plan to make an x-ray spectrometer as hobby. Penetration isn't necessary nor important. I wonder what would be the minimum usable energy to stimulate the atoms on the substance surface? Should the applied energy vary according to the properties of the analysed substance (i.e, atomic weight)?

author: Fraser
author_rank: Super Contributor
timestamp: April 03, 2015, 07:42:09 pm
content: http://citizenscientistsleague.com/2012/12/28/alpha-particle-x-ray-spectroscopy-x-ray-fluorescence-in-the-home-lab-or-fun-with-quantum-physics/XRF can be carried out with nothing more than the sources out of ionisation smoke detectors. You can also buy miniature pyroelectric X-Ray generators for XRF but they will be hard to find and expensive. Datasheet attached.The other X-Ray source worthy of consideration is the Russian BS7 W transmission type X-Ray tube. A very 'cute' tube that produces a 5 Degree beam width of just the right power for Crystalography and XRF as that is what it was designed for. It requires a 1.5V heater supply and a 12-15kV EHT at very low current. Sadly the source I bought from has sold all stock and I sold my two units ages ago. A colleague of mine did buy several and if you get really stuck I could always ask if he wants to sell one.http://www.hardhack.org.au/xraydtthttp://www.hardhack.org.au/crystallographyIIRC they cost around $60 eachhttp://www.sovtube.com/x-ray-and-geiger-tubes/317-bs7-w.htmlAurora

author: mete
author_rank: Newbie
timestamp: April 04, 2015, 07:55:13 am
content: These ones are very useful information for me. Thank you for your response at speed of light

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 04, 2015, 09:47:45 am
content: That Russian tube site also has some scintillation detectorshttp://www.sovtube.com/33-scintillators-

author: zze110
author_rank: Contributor
timestamp: April 11, 2015, 07:23:42 pm
content: Quote from: Aurora on December 22, 2014, 08:42:51 pmI used to perform maintenance on a Yxlon Y.Cheetah($800K machine) and it could barely produce photos as clear as what you've posted. Most systems seem to use a flat panel detector now where-as ours used a photo intensifier tube. I had to run the machine at 80kV to match the quality of the images on page 1 (could go as high as 160kV if needed). So, that quality for only $57k is remarkable.

author: Fraser
author_rank: Super Contributor
timestamp: April 11, 2015, 07:45:33 pm
content: I am very pleased with the images that my Faxitron MX-20 produces. The images of the ethernet PCB that I provided on page 1 are actually quite poor quality as there are a lot of compression artifacts. The MX-20 can also save in RAW format or TIFF and those provide far better image quality. The images are 4Megaixels and very crisp, even before employing any of the provided image processing algorithms.I was lucky to find my unit and the supply seems to have dried up at the moment. There may be more disposed of after the end of financial year equipment refresh (April in UK).There is one Faxitron MX-20 for sale on ebay at the movement and it is being sold by my friend. The sad news is that it has no PC or camera interface card. Without the interface card, the camera cannot be operated on this circa 2004 model.Aurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 11, 2015, 09:53:44 pm
content: Quote from: Aurora on April 11, 2015, 07:45:33 pmThis would be an interesting exercise in reverse engineering though... I've looked at data for a few flat-panel detectors, and their interfaces have been relatively straightforward, usually one or two parellel buses over LVDS.Someone has already made a lot of progress on this :http://photonics.engr.uga.edu/xray_imager/index.htmlAnd you could always use it with film.

author: Fraser
author_rank: Super Contributor
timestamp: April 11, 2015, 10:54:30 pm
content: The camera connector has 4 coaxial elements in it like in the attached image. It is unlike teh later high density D type used on my unit.Auction is here for anyone interested:http://www.ebay.co.uk/itm/Faxitron-X-Ray-Specimen-Radiography-System-Model-MX-20-/151630915830?pt=LH_DefaultDomain_3&hash=item234de828f6It is fitted with a DC-2 camera which has a 50mm x 50mm imager array.This would make a very safe X-Ray experimentation cabinet as you suggest Mike. Alternative camera or film technology could be used.Aurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 11, 2015, 11:01:01 pm
content: Quote from: Aurora on April 11, 2015, 10:54:30 pmThe D9 is presumably serial for the x-ray control - I wonder if maybe the coax connections are analogue out for an external ADC.Either that or maybe something like SDI digital video. Perhaps even VGA+sync?Could be worth asking the seller to unscrew that mounting plate to see if there is a make/model on the sensor.

author: Fraser
author_rank: Super Contributor
timestamp: April 12, 2015, 11:50:34 am
content: @Mike,I don't think the seller has the spare time to delve deeper into the unit. I may be able to assist him with further investigation but the value of the unit will not increase unless I sort out a computer interface for him that works with imaging software. It will likely take more time than its worth. There may well be a hobbyist out there in ebay land who wants to spend the time on it though.The D9 is serial control of the X-Ray Generator and is driven from teh computers serial port. The Software that I have will run the 2004 year MX-20 and DC-2 camera but you need the original camera interface card to match the drivers.The camera is a Bioptics unit running the usual diode arrays. (as fitted to my unit). It is the output interface from the camera that differs. Those imaging arrays cost a small fortune and are worth the GBP650 alone. I was tempted to experiment with the unit but now that I am retired I have to be more sensible with fundsAs to the function of the 4 coaxial connections. I have no idea. It is a monochrome imaging array though so RGB would seem unlikely but I really have no idea without delving into the base of the unit.I will advise when other Faxitron's become available...... there will be others.Aurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 12, 2015, 12:08:39 pm
content: Quote from: Aurora on April 12, 2015, 11:50:34 amThat's what I was getting at - would be an interesting project - If I didn't already have my unit (or it was a larger sensor) I'd certainly give it a go.ID'ing the sensor could provide significant info as to feasibility and could help it sell - probably worth 5 mins to undo a few screws!QuoteI'm sure the serial protocol is simple, but you don't even need that as you can operate the x-ray form the front panel.QuoteDo you know that or are you assuming? Seems Bioptics merged with Faxitron at some point, though my unit has a Hamamatsu sensorQuoteWon't be RGB but could be multiple parallel streams, or clock + 2 data+syncQuoteKeeping my fingers crossed for one with a 4" sensor and no PC for some reverse-engineering

author: Fraser
author_rank: Super Contributor
timestamp: April 12, 2015, 01:07:27 pm
content: @Mike,For camera types see my posting in your teardown thread:https://www.eevblog.com/forum/reviews/faxitron-mx-20-x-ray-system-teardown/msg585779/#msg585779Camera types confirmed with Faxitron service agent in USA.Bioptics were the original supplier of cameras to then MX-20, then Hamamatsu (interim supplier when Bioptics made their own cabinets), followed by Bioptics againI will let you know if I hear of a 4" x 4" Faxitron. Mine is serving me very well. The 4" x 4" array has met all my electronic imaging needs, but I still envy your USB connectivity and better software with auto exposure mode and full control of the MX-20 chassis. I will not be upgrading however as they are not exactly cheap and my images are great already.Aurora

author: chefkoch84
author_rank: Contributor
timestamp: April 13, 2015, 02:48:39 pm
content: Hello all you X-Ray and generic nerds.I am a silent follower of the forum and Mikes and Daves video blog since ages.Thanks for all the knowhow and entertainment first of all!!!I was wondering if it would be useful to adopt one of those planar x-ray machines to act as a topographic scanner. (XCT)I got in contact with cone-beam xct reconstruction during my master-thesis and figured that it is surprisingly easy.E.g. it would be possible to rotate a (rigid) object in the FOV of a planar scanner for instance by a stepper motor and use the projection images to reconstruct a x-ray volume.I can recommend this open source software:http://www.cs.toronto.edu/~nrezvani/OSCaR.htmlIts not super fast.. but very easy to understand and adopt.I am a bit jealous on people to can afford the space to have their own x-ray device :-)... so probably will not happen for me in the near future.If somebody is interested I would be happy to take a shot and try to reconstruct a volume of a row of X-ray projections.GreetingsMax

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 13, 2015, 08:23:37 pm
content: Yes - CT scanning is something on the list of things to try when I get round to it.

author: wilheldp
author_rank: Regular Contributor
timestamp: June 19, 2015, 01:57:18 am
content: I've been trying to find a second hand, *operational*, cabinet x-ray machine for a reasonable price for several months now with no luck. There have been several Faxitron's on eBay, but almost none of them come with the computer which is absolutely essential to getting an image from the digital sensor. I came across both an operational Faxitron and an operational Kubtec, but both of them were going for over $10,000USD.I came across this Chinese job this evening...http://www.ebay.com/itm/Portable-X-Ray-Inspection-System-For-PCB-BGA-Electronic-Desktop-Testing-10Kg-/131434686944?pt=LH_DefaultDomain_0&hash=item1e9a1e29e0I cannot find anything outside of eBay with that part number (AJ-1600), and there don't seem to be any reviews. Has anybody come across any reviews or user-generated x-rays from this unit? $6,000 isn't too shabby if this thing generates decent images.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 19, 2015, 06:46:33 am
content: The "internal structure" pic shows one of the cheapo portable dental units, which have been banned by the UK authorities due to inadequate shielding, though inside a box it's probably less of an issue.However I doubt it's a microfocus tube, so achievable resolution is probably less than the sensor resolution might suggest, and probably also not capable of geometric magnification to the extent that the faxitrons can do. May also not produce as good an image for devices that can't be held very flat & close to the sensor.I believe x-ray gear is more regulated in the US than her in the UK, which may explain the lower availability.If you find a unit without a PC going cheap, all may not be lost of you can find the make/model of the sensor, as some will use standard PC cards (or USB if you're lucky).

author: wilheldp
author_rank: Regular Contributor
timestamp: June 19, 2015, 12:25:46 pm
content: I did some more reading on that listing and asked the seller what the sensor size was. The specs seem contradictory. The sensor size is only 3.6cm by 2.7 cm, with 1600x1200 active pixels. That translates into a ludicrous ~2000 pixels per square mm. But the image resolution is just listed at ">12 lp/mm". Whatever...I'm not really interested in a $6000 machine that can only X-ray stuff 1.5 x 1 inches.Do tell about the Faxitron image sensors. I've only seen units with that beast of a connector (looks like D-sub with 5 pins and 4 coax). I've been hesitant to even look at units without the computer because I thought they only came with the proprietary interface. Is there something in the model number label that denotes it has a standard or USB-capable sensor? I've seen the cabinets going for sub-$1000 all over the place.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 19, 2015, 12:36:02 pm
content: Quote from: wilheldp on June 19, 2015, 12:25:46 pmlp/mm means lines per mm resolution. This is probably a combination of x-ray source and detector, and probably also the scintillatorThe problem is IDing the actual sensor. Some cabinet manufacturers will use bought-in sensors, and not necessarily the same one over the product lifetime.My Faxitron uses a Hamamatsu USB sensor, for which there is some documentation and software available from Hamamatsu.I've seen some sensors that use a standard card from someone like National Instruments.This guy has been doping some reverse engineering of a different sensor in a faxitron cabinethttp://photonics.engr.uga.edu/xray_imager/index.htmlIf you ever come across a unit with a 4" sensor going cheap, let me know..!

author: wilheldp
author_rank: Regular Contributor
timestamp: June 19, 2015, 01:10:40 pm
content: Quote from: mikeselectricstuff on June 19, 2015, 12:36:02 pmI actually just read that guy's whole article. Sadly, it ends with a "to be continued..." I was really hoping it would end with "and you can buy my sensor board for $xx dollars."Unfortunately, the only Faxitrons I have come across have had that proprietary connector poking out the back. If somebody could reverse-engineer the sensor and connector and make a PCI interface card for it, they could make a fortune on the second-hand Faxitron market.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 19, 2015, 01:27:30 pm
content: Quote from: wilheldp on June 19, 2015, 01:10:40 pmLet me know if you come across one for under $500 (just the sensor) - I'd be willing to have a crack at it.

author: wilheldp
author_rank: Regular Contributor
timestamp: June 19, 2015, 02:54:23 pm
content: Wish I'd known that a while ago. I had an eBay seller offer me one for $400 a while back (he had it listed for $800, no computer, cables, or manuals). I'm sure shipping to the UK would have been more than the cost of the machine, though.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 19, 2015, 03:11:31 pm
content: Quote from: wilheldp on June 19, 2015, 02:54:23 pmYes but as long as they would be prepared to remove the sensor and just ship that, it wouldn't be a problem

author: wilheldp
author_rank: Regular Contributor
timestamp: June 19, 2015, 10:57:14 pm
content: Touche...I'll keep my eye open and PM you if I find anything. I'll buy it, remove the sensor and ship it to you.

author: Fraser
author_rank: Super Contributor
timestamp: September 05, 2015, 03:16:16 pm
content: Resurrecting an old thread but I just used the MX-20 to identify the contents of an inductive probe used with the POLAR Toneohm series of short tracers. This is a typical practical use of X-Ray imaging for the hobbyist and reverse engineering practitioner. The probe costs £40 and is just a tube, coax cable and SMD bobbin inductor at the tip ! With the X-Ray images it is possible to see that no other components are present in the barrel of the probe. the inductor measures 9.6 Ohms and its inductance will be measured with an LCR meter in the knowledge that it is an inductor on the end of a piece of coaxial cable.For the images and discussion of the Toneohm shorts tracer see here:https://www.eevblog.com/forum/testgear/toneohm-850a-short-finder-by-polar-instruments-a-look-under-the-hood/msg747124/#msg747124The X-Ray images are not that good as this was all done as a favour in a hurry to assist a fellow forum member. Quick and dirty best describes the imagesAurora