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ChrisLX200
United Kingdom
35 Posts |
 Posted - 06/28/2017 : 08:33:38
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Just thought I'd say hello afer having bought a 300E+ and registered on the forum :)
The detector worked right out the box, the background being stable @ 26-29cpm. However (like everyone else I guess) I wanted to test it with a more active RA source. Eventually I dimly recalled having a kids chemistry set 50 years ago (!) but it took an hour rooting in the loft to find it in a taped-up box. Some fun chemicals in there were vials of Thorium Oxide and Uranium Acetate - and a tiny tube of something I inherited from my grandfather (a watchmaker by trade) which was used to paint luminous hands on watches etc. That used to be a 2-part compound, one being the green/yellow powder and the other some sort of resin, and they were presumably mixed before being painted on.
Anyway, the Uranium sample provided 2100cpm, the Thorium 2600cpm, but the luminous power nothing (which surprised me - I was quietly worried what it was made of!). Of course the 300E-plus is not sensitive to alpha particles so I don't know what activity they may have there, and I did not open the vials - just rested the glass bottles on the outside of the detector casing.
I noted the GeigerLog Python script utility and tried to get it working under Win7-64 (I have Python v3.5 64-bit installed) but I failed miserably to get it to run. Anyone know for sure that it would/should run in that environment?
Cheers,
Chris |
GMC-300E-plus |
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| Reply #1
ullix
Germany
1171 Posts |
Posted - 06/29/2017 : 05:29:23
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| GeigerLog requires Python 2.7 environment; see Manual |
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| Reply #2
ChrisLX200
United Kingdom
35 Posts |
Posted - 06/29/2017 : 08:24:52
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I did notice that - that it developed under V.2.7 - but I thought V.3.6 might be backward compatible. I use another package that works under both Python versions.
I modded my casing on the 300E+ so the tube can see a bit more daylight. For that I used my milling machine. The case is obviously weakened by doing this but should still be strong enough provided it isn't dropped. The background count does not appear to be significantly affected by this modification, but it's so variable at this low level it would require a large sample (days) to tease out the stats. I guess it should increase relatively. However, the active sample readings I get are now definitely higher than before, the Uranium Acetate gives 4640cpm, the Thorium Oxide gives 4150cpm, and those are getting on for double the count I was recording prior to modding the case. Again, those data are with the material(s) still inside their glass vials (as far as I can remember these samples have never been opened). Pictures of the vials are below, including the mysterious luminous paint which still fails to register a count. Given the relatively high counts (and the 300E+ isn't that sensitive) perhaps I should consider storing them in a lead pig rather than a cardboard box! :) These chemicals were purchased mail-order from a London supplier over 45 years ago and I doubt it would be so easy to get hold of them now!
edit: OK, well posting images on here is beyond me. They work in preview mode but then it complains external links not allowed...
edit2: It seems the forum doesn't like files named in CAPS (ie., JPG instead of jpg), upload fails with 'unknown filetype" :-) I still can't get external image links to work though which is a pain because most of my stuff I store on PhotoBucket.
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Edited by - ChrisLX200 on 06/29/2017 16:24:16 |
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| Reply #3
GBG12
Canada
101 Posts |
Posted - 06/29/2017 : 17:27:15
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Regarding the green/yellow powder on the right, if it contains Radium 226 it would be an alpha emitter, and the glass tube blocks that. It would no longer glow due to the short lifespan of the phosphor normally mixed with it, but Radium 226 itself has a half-life of 1600 years. An alpha sensitive meter would confirm this after opening the glass vial. ** I would be afraid to expose myself to an alpha emitting powder. Breathing it in would likely cause lung cancer!
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Edited by - GBG12 on 06/29/2017 17:28:30 |
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| Reply #4
ullix
Germany
1171 Posts |
Posted - 06/30/2017 : 01:44:15
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Python 2.7 and 3.x programs are only compatible if certain provisions are made, which, however, will impact the compatibility with other Python 2.7 modules! GeigerLog needs the latter and has not made these provisions.
The effect of your modding (nice machining job, by the way!) is to remove the case, which largely blocks the beta radiation, the dominant detectable radiation. I went a step further and took off the backplate completely. The case barely impacts gamma radiation.
Stopping power of matter is discussed in more depth in the appendix to my Potty Training ( http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=4558 )
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| Reply #5
ChrisLX200
United Kingdom
35 Posts |
Posted - 06/30/2017 : 02:39:25
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quote:
Originally posted by GBG12
Regarding the green/yellow powder on the right, if it contains Radium 226 it would be an alpha emitter, and the glass tube blocks that. It would no longer glow due to the short lifespan of the phosphor normally mixed with it, but Radium 226 itself has a half-life of 1600 years. An alpha sensitive meter would confirm this after opening the glass vial. ** I would be afraid to expose myself to an alpha emitting powder. Breathing it in would likely cause lung cancer!
Thanks for that :-) The powder does glow a little for a short time if held in light and then moved to darkness. I didn't keep the resinous 2nd part which had solidified, and that was many years ago. Trying to work out the age of it is difficult, could be anywhere between 1920-1950, that's when my grandfather was most active as a watchmaker/repairer. Again, I don't recall this vial ever being opened and was only kept as a curiosity (I also inherited many of his watchmaking tools which were far more useful). I don't have a meter sensitive to alpha but the vial will be treated with much more respect from now on!
Another thing I need to root out then is an old luminous instrument from a WWII aircraft I have someplace - that never had a glass dial (must have been broken) and it sounds like it would also be hazardous due to the luminous paint.
ChrisH |
GMC-300E-plus |
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| Reply #6
ChrisLX200
United Kingdom
35 Posts |
Posted - 06/30/2017 : 02:58:45
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quote:
Originally posted by ullix
Python 2.7 and 3.x programs are only compatible if certain provisions are made, which, however, will impact the compatibility with other Python 2.7 modules! GeigerLog needs the latter and has not made these provisions.
The effect of your modding (nice machining job, by the way!) is to remove the case, which largely blocks the beta radiation, the dominant detectable radiation. I went a step further and took off the backplate completely. The case barely impacts gamma radiation.
Stopping power of matter is discussed in more depth in the appendix to my Potty Training ( http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=4558 )
Thanks Ullix, yes I understand that - I recall the (only) other Python package I use was initially developed under 2.7 but then updated to work with the newer revision. It was a fair amount of work to do that. I'm not a programmer so getting Python scripts to work for me is non-trivial :-)
I think it was that thread (and others) which prompted me to make this case modification. Also, other threads on substituting the geiger tube for different one are interesting - perhaps one sensitive to alpha would be useful. Being 'blind' to alpha emitters is not a good situation, if this 300E+ cannot be modded then another meter of some sort may be the best alternative. The 300E+ is cheap though - might be better to buy another one and mod that rather than throw a wad at a more sophisticated instrument?
ChrisH |
GMC-300E-plus |
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| Reply #7
ullix
Germany
1171 Posts |
Posted - 06/30/2017 : 04:10:27
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Be aware that ALL (!!!) of your powders are alpha emitter! You just can't measure anything with the supposed Radium vial, because Radium has almost no beta, while the others have.
Follow the decay chains of those heavy elements, and you find that they are all stronger in alpha emission than in beta emission. For a simple estimate just count the vertical versus the diagonal dashes in the decay schemes here https://en.wikipedia.org/wiki/Decay_chain
If you could find a tube with an alpha window which runs on a similar voltage as the current M4011 tube, you could simply connect it to the anode and cathode clips, and would not even have to take out the current tube!
However, you would still not be able to measure alpha as the glass of the vial absorbs all or at least by far the most alphas. And as for opening the powder vials see GBG12's comment.
Better leave those genies in the bottle! Hence you won't need alpha capabilities.
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| Reply #8
ChrisLX200
United Kingdom
35 Posts |
Posted - 06/30/2017 : 06:55:47
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| I can (and will) leave those samples sealed but I need to check the area around where they had been stored for many years, and also check for several other old items like the aforementioned WWII aircraft instrument and watch/clock parts. There is potential for contamination with alpha emitters and I'd like to be sure. |
GMC-300E-plus |
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| Reply #9
ullix
Germany
1171 Posts |
Posted - 07/01/2017 : 00:27:09
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Correction: I just noticed that Radium is not a pure alpha emitter, but should be associated with gamma and beta as well https://www.ld-didactic.de/software/524221de/Content/Appendix/Ra226Series.htm
Ra226 may emit gamma subsequent to an alpha emission, and in the decay chain there is beta and more gamma. So the fact that you can't measure anything with that 3rd vial suggests that it is something other than Ra226. |
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| Reply #10
Distelzombie
Germany
202 Posts |
Posted - 07/01/2017 : 13:10:31
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| I have several vials with Ra226 which were used in watch repairs. I can measure 30k CPM on the outside with my SBT11a. (Alpha is still blocked by the glass) |
GMC-300E+ V4.20 with sbt-11a alpha tube
My statements are "stuff-a-hobbyist-says" and not in any way professional. |
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| Reply #11
ChrisLX200
United Kingdom
35 Posts |
Posted - 07/01/2017 : 14:51:54
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Thanks guys. Well I can't get a count on my tube so it sounds like it's not Ra226 - which is something of a relief I suppose. The 300E+ is definitely working fine as it readily detects the two other samples and also an Americium disk from an old smoke alarm I had. Still looking at options for adding alpha capability though, I may just stump up for a Mazur PRM9000 or a Ranger.
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GMC-300E-plus |
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| Reply #12
GBG12
Canada
101 Posts |
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| Reply #13
ChrisLX200
United Kingdom
35 Posts |
Posted - 07/16/2017 : 13:32:05
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I've been playing with a new UV torch (365nM, 5 watt) I bought the other day, seeing if any of these samples are fluorescent. Under direct lighting with the torch the mysterious tube glows a brilliant green, as does the Uranium Acetate. The Thorium Oxide (a white powder under normal lighting) glows/reflects a deep yellow colour but doesn't seem to actually fluoresce. On removing the UV light the Uranium stops fluorescing immediately, whereas the mysterious tube continues to glow for 10-20 seconds gradually dimming.
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Edited by - ChrisLX200 on 07/16/2017 13:35:37 |
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| Reply #14
ullix
Germany
1171 Posts |
Posted - 07/17/2017 : 00:06:14
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Nice pictures! 365nm light is invisible to the human eye. It is perfect for killing bacteria on surfaces, and ruining your eyes. It is similar to looking into an electric welding arc!
When the "fluorescence" lasts for several minutes, it is called phosphorescence. On the atomic scale the electronic excitation lasts not microseconds (or shorter) as for fluorescence but up to (many) minutes. Given the origin with your watchmaking grandpa it makes sense as a dye without radioactivity, as at least for some time watches had glowing hands and dots at the hour marks, which had no radioactivity. However, you had to switch the light on to activate the dye, which defeats the purpose of having something visible in the dark :-/
You can buy it today as this Glow-In-the Dark stuff. Not sure what your product is, but unlikely to be dangerous. Could still be chemically not up to today's standards.
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GMC-300E+ new owner
