EEVblog #776 - World's Smallest Digital Dosimeter

[EEVblog]

A look at the Ultra Micron, the world's smallest digital ionising radiation dosimeter, and it's Open Source Hardware.
https://github.com/shodanx/ultramicron

[alimirjamali]

I wish if Andrey sold this device.  He did an excellent job

The Windows software is available on his Github repository which is written in Delphi. Should be very easy to translate to English.

Thank you very much Dave for review and tear-down 

[nitro2k01]

What I want to know is how well it can tolerate higher radioation levels, in terms of not crashing and so on. Do rad hardened micros come in such small packages?

[sergey]

Very nice, Andrey!

Dave, uR/h is rather quite common in russia actually, so not a problem here at all And thanks for the teardown!

[Artlav]

Tried to translate the software, but it won't compile for me. Needs some post-7 (and so braindead) version of Delphi.
So i only translated the screenshots:

[dadler]

I really want one of these!

[LabSpokane]

Wow!  I thought I had seen a small dosimeter until now.  It'll be interesting to see what shows up in the nuclear pavilions at the power trade shows with this new benchmark.

[Stonent]

Datasheet for the SBM-10 http://www.gstube.com/data/2396/

More info about Soviet surplus tubes: https://sites.google.com/site/diygeigercounter/gm-tubes-supported

The SBM-10 is not particularly sensitive tube, but it is small.

If you remove the inside of the smoke detector from the housing, you can get a lot more activity from the Americium.

Another interesting thing to test is Potassium Chloride, sold as "Lite salt" or sodium free salt.  Potassium and Potassium chloride typically contain enough K-40 in it that it will increase your activity by several ticks per minute.  It's not dangerous, it's just that's the way Potassium exists in nature.

Another thing to keep in mind is dosage is highly dependent on the material being tested.  A geiger tube is only a counter. It has no ability to measure magnitude.   As far as it is concerned, one click of Potassium 40 is the same as one click of Plutonium.  So the meter has to be calibrated to the sample.   You could think of it as a device that counts cars passing by on the road. A Smart car is the same as a 18 wheeled diesel truck.  Typically counters are calibrated to CS-137 or in the case of the CDV-700 counter I have, calibrated to depleted uranium.

If you did want to measure magnitude of unknown samples, you'd need a scintillation counter.

So if you are measuring to anything other than it is calibrated to, make sure if you know what you're measuring, do some googling and see how you can covert counts to sieverts for your sample.

And remember, half-lives have to do with how much radiation is spewing out.  Short half-lives mean lots of radiation, long half-lives mean slow emissions.

[jnissen]

Dave, if your interested you may be able to interface the dossimeter into a world map. I am using the following service as it's free and the guys here support many different devices. Perhaps they can support your meter? Give them a try.

http://radmon.org/

[elektronaut]

That's a really nice dosimeter.
Can this one be used in an environment where one is prone to be exposed to X-rays?
In other words in situations where the exposure is very short but somewhat intense.

[Someone]

Argh, never heard anyone pronounce it that way before. The manufacturers videos and professionals I have worked with always pronounced it "dose-im-eter" emphasis on its function of estimating dose.

That's a really nice dosimeter.
Can this one be used in an environment where one is prone to be exposed to X-rays?
In other words in situations where the exposure is very short but somewhat intense.

The detector used in this small unit is sensitive almost exclusively to gamma radiation, it would be a very poor choice as a general purpose dosimeter or for use with narrow energy emitters such as x-ray equipment. They are intended for consumers worried about nuclear hazards.

[Pentium100]

I noticed one mistake in the display. The dosimeter displays uR/h current level, but then the day dose is in uRh. Why? Roentgen is a measure of dose, you do not need to multiply it by hours. For example, joules - you can measure power in J/h, but won't measure the total energy in Jh.

I know this is pedantic, but for some reason I really notice this kind of mistake. For example, saying that a lightbulb uses 100W/h.

[99tito99]

Hi Folks,

MegaNubie question/request: Can someone point me in the right direction to cut-my-teeth on understanding GitHub?

I'm opening and looking at files and it's a bit of a train-wreck in my brain.

Cheers,
Mark
***********************

[elektronaut]

Can someone point me in the right direction to cut-my-teeth on understanding GitHub?
I'm opening and looking at files and it's a bit of a train-wreck in my brain.

In the readme.md file this links shows up ftp://www.xn--80aighkbzclf7a.net/%D0%94%D0%BE%D0%B7%D0%B8%D0%BC%D0%B5%D1%82%D1%80%D1%8B_%D0%9C%D0%B8%D0%BA%D1%80%D0%BE%D0%BD/%D0%A3%D0%BB%D1%8C%D1%82%D1%80%D0%B0-%D0%BC%D0%B8%D0%BA%D1%80%D0%BE%D0%BD/ here you can download all files in a simple way

[99tito99]

Can someone point me in the right direction to cut-my-teeth on understanding GitHub?
I'm opening and looking at files and it's a bit of a train-wreck in my brain.

In the readme.md file this links shows up ftp://www.xn--80aighkbzclf7a.net/%D0%94%D0%BE%D0%B7%D0%B8%D0%BC%D0%B5%D1%82%D1%80%D1%8B_%D0%9C%D0%B8%D0%BA%D1%80%D0%BE%D0%BD/%D0%A3%D0%BB%D1%8C%D1%82%D1%80%D0%B0-%D0%BC%D0%B8%D0%BA%D1%80%D0%BE%D0%BD/ here you can download all files in a simple way

Hi elektronaut:

Thanks, that focused me in and helps a lot.

Cheers,
Mark
*********************

[TiN]

Nice piece of russian engineering

And meanwhile, EEVBlog not supporting russian language posts!?

P.S. ? , Nah, not supporting, changes posts/PMs to bunch of questions marks.

[Rubi]

Hi

Since it's open source hardeware where can I find the pcb files ?
I could not find them in the github folder, did I overlook something ?
I would love to build one.

Cheers
Michael

EDIT
Please excuse, after removing the tomatoes from my eyes I found the pcb files and ordered them from osh park.
8$ for three pcbs, awesome!

[bitwelder]

Hats off to Andrei for making this little beauty! 

Besides, looking at the files in www.xn--80aighkbzclf7a.net I see that before Ultra-Micron there was a Micron project, running several versions, with older versions dating back to 2012.
So the device we saw in Dave's hands is likely the result of a long evolution process.

Thanks also for releasing it as open source.

[LabSpokane]

Shodan,

I forgot to thank you.  Projects like this are what make it fun to visit here.  Nice work!!

[SEKCobra]

Man, I'd love this as a kit, maybe a bit more rugged case (Like Honeywell CO Warners maybe?).

[Stonent]

Please excuse, after removing the tomatoes from my eyes I found the pcb files and ordered them from osh park.

I recommend use Seeedstudio, because it have better "Annular Ring" PCB limitations.

bit more rugged case

This case(from Dave video), the best and small what i can found.
Key thing it is small.
As one option to order the plastic case molding in the factory, but it is very expensive.

I thanks to everyone!
I was interested to read the comments.
Glad that you liked the project.

No, i not sell "kit".
But if you can find more 60% components yourself, maybe i can help you.... i can send to you rare components by mail.

Sometimes i sell 1-3 pieces(fully assembled device), but it very expensive price. Therefore i recommend bying components and assembly it yourself, it more cheaper.

Well one thing I like is if you have the full schematic, you can modify it as needed.
For instance building the HV section and then being able to sample the voltage would be what I would be most interested in.  As long as I can get pulses from that, I could use another MCU if I'm more comfortable with it.

[dmg]

Well, I'm building one or two of these I'm amazed of the PSU design, very nicely done. I've already ordered all the components. For your reference on things I've found difficult to get:

I'm 99% sure that these are the cases:
http://www.aliexpress.com/item/plastic-case-small-6-pcs-49-27-18mm-electronic-project-box-electronic-case-abs-swith-housing/32219511996.html
It has the exact inside dimensions and looks very similar on the outside.

This is the only source I've found for screens:
http://www.aliexpress.com/item/Original-LCD-screen-digitizer-display-Second-External-LCD-For-Nokia-2760-Mobile-Phone-Repair-replacement-Tools/1822978844.html

As for the vibration motors the ebay seller listed on the motor parameters ( ebay store 4hobbyde) seems not to be carrying them, but no worries, I'm 99% sure they are these:
http://www.ebay.com/itm/231218458556?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

SBM-10 tubes are readily available on ebay from lots of sellers, no problem there.


As for the rest of the electronic components all of them are readily available on digikey and mouser. Well, there are no matching tactile switches on mouser but those can be found on ebay for dirt cheap (the model listed on the BOM is from a russian store but it's standard. So is the orange LED, any 1206 orange led will do). It gets cheaper on mouser. Only things I've found are that:

- ATB322515-0110 transformers are out of stock everywhere until september 2015, but you can get ATB322524-0110 which seems to be fully compatible, just a bit taller (same series, same datasheet, higher current rating)

-ABM7-8.000MHZ-D2Y-T has a unique footprint and there are literally no other crystals on that size and frequency anywhere. They are out of stock until late october 2015 in mouser and digikey, thankfully they're in stock at farnell and I had to make an order there anyway. I've ordered extra in the case anyone needs. I was about to change the crystal for something in 5032 package which is more readily available but I had already ordered the PCB's. Elecrow seems to be happy so far with the gerbers. Looking at the design rules and browsing the PCB it seems that the tolerances are within the capabilities of all 6mil/6mil chinese manufacturers.
 
Total cost ordering in 1's is about 60€. If anyone is interested I can share a cart for digikey/mouser with everything you need in exact quantity (once you stockpile about 8 large boxes full of leftover SMD's you start seeing the value of ordering just two damn 0603 resitors even if that's more expensive than ordering 25 or 50 as you did when your room had more space)

I've ordered six cases and I have a milling machine that can do plastic. I only plan on building two of these and once I get the milling machine set up right I might machine all six cases so I might offer them here if anyone is interested. I plan on using a CD as a source for polycarbonate windows.

I'll tell you how it goes when It's built. Very nice project.

[dmg]

Display - Last time i buy here, but it expencive.
Case - I use this, but you is very similar.
Transformer -  ATB322524-0110, yes, it will be work fine.
Crystal - yeah.. its very rare thing.... But i buy it on Farnell.

Thank you very much, I'm pretty sure that my case is exactly that one. I've seen the exact same model I ordered listed elsewhere with the same dimensions as yours (in my link the case is listed with a height of 18mm but I've see it listed as 14mm with the exact same part number. You know, chinese millimeters aren't always as everywhere else's millimeters).

 By the way, is there anything else I need to know before building the 4.06 version? I've seen that the design is mostly the same as 4.04 except for a 1.6ohm ferrite which is now a 22 ohm resistor and an extra mosfet at the HV power supply. Will it work with the current firmware? I've also read in your blog something about some resin that you applied to the positive terminal of the geiger tube but later you had to scrape off the PCB but I didn't understand very well. Could you explain? I have a friend who speaks russian and could help but she's on holiday.

EDIT: I have a CNC milling machine. The window for the screen and the holes for the buttons are easy to make but the USB micro hole will require a custom tool to support the case in a vertical position. I hope the plastic is ABS or something easy to machine. I'll make a 3D model of the enclosure when it arrives and hopefully I'll get it right before the 6th trial.

[AccountRemovedPerUsersRequest]

Well, I tried to recompile English translated Win-software, but too many 3rd party version depended files required.

Axel.

[AccountRemovedPerUsersRequest]

Just install Delphi JCL

That was obvious. But besides Jedi there are some missing properties (modified std Classes?), missing VCL(s) (at least MyTray), version conflict between Jedi and zlib object files (or pngimage-source... can't say), modified or updated Indy... etc etc.
Anyway: too many conflicts between my D7 and dosi-win software.

If it were only changing some texts and recompile I would do that. Investigating and reverse engineering goes beyond my economical effort in this case...

Axel.