"BetterGeiger S-1" - Low cost scintillator detector

[BetterGeiger]

Getting closer to launch:

https://twitter.com/BetterGeiger/status/1463939724897308679

[BetterGeiger]

The last post was a bit premature, now the user interface is really complete. (although further improvements/additions might still come...)

This is a video showing it:

https://twitter.com/BetterGeiger/status/1466833394608721920?s=20

I am doing final testing to try to be sure there are no hardware or firmware bugs left. After that I will launch the Kickstarter, then I will order larger quantities of PCBs etc. I should be able to ship out orders 1-2 months after the Kickstarter. The most uncertain part will be CE certification, but the board does not have anything which I expect to create any RF interference problems. Worst case is some more PCB changes are needed.

[BetterGeiger]

Here is the big update!

Kickstarter is live, there is also a video demonstration and some new details in the text.

https://www.kickstarter.com/projects/bettergeiger/better-geiger-radiation-detector?ref=azp6uz

[DG0MG]

Kann Kickstarter mit Paypal umgehen? Ich lese nur was von Kreditkarten ..

[BetterGeiger]

Unfortunately not. Maybe with debit card (like Maestro) but I'm not sure. If you cannot find a way then please send a message on the contact form of www.bettergeiger.com and I can try to find an alternative solution.

[BetterGeiger]

Friendly reminder, 48 hours to go:

https://www.kickstarter.com/projects/bettergeiger/better-geiger-radiation-detector?ref=b6v7au

And a copy/paste from a project update I posted:

"There has been a lot of interest amongst DIY enthusiasts in having access to the raw signal on the board so that they can connect it to their own data-logging device or whatever else.  I was hesitant make that an accessible feature because it can easily lead to user mistakes and fried electronics, but on the other hand I know people will do it anyway and I do really love seeing projects like that. So, I've decided to add some connection points onto the board to make that easier to do and perhaps less risky (compared to trying to go in blind trying to reverse-engineer the contact points). There is one caveat, though - if something goes wrong and you kill your detector please don't ask me for a replacement, as this is not an officially supported use of the device. "

...that should include analog pulse signal and digital trigger signal. Probably an analog output for time-averaged dose also but I'm not sure certain.

[DG0MG]

Hat denn jemand das Gerät gekauft und kann mal berichten?

[DG0MG]

This is a video showing it:
https://twitter.com/BetterGeiger/status/1466833394608721920?s=20

Bitte benutze für die Einheit "Mikrosievert pro Stunde" die Abkürzung "µSv/h".
"µS/h" sind MikroSIEMENS po Stunde.

[BetterGeiger]

Hello all,

Kickstarter shipments have begun, about 100 so far. I hope to get fully caught up Kickstarter shipments and web site orders (www.bettergeiger.com) in the next 2-3 weeks. After that I will try to have enough on hand to ship orders quickly. If I can maintain production to match demand depends on how many orders there are and how quickly my suppliers can continue to ship me critical components (as we know, things like that are complicated right now).

I have not seen an public reviews yet, but private feedback so far is positive, but it is still early so I don't know yet if unexpected problems will be found.

Regarding display units, I had to make difficult design choices in what and how information is displayed on the screen. In order to make everything fit I decided to shorten Sv to S and rem to r on the display. It's not ideal but I think it was my best option. I hope users will have enough common sense to understand that it is Sieverts and not Siemens. It is also explained in the user document:

https://www.bettergeiger.com/user-documents

Some other topics...

Beta measurement: The main thing I have learned between when I started the Kickstarter to now is that when measuring a source which is mainly beta and also distributed (not a point source) then the performance difference between my detector and a traditional GM tube is more than I originally thought. Generally with beta sources the area of the detector is extremely important, and because a scintillator is dense and small it is worse than a GM tube which is low-density and large. This I already knew, but with a point source the difference is not so dramatic because you can put the scintillator close to the source and cover a large solid angle even with a small sensitive volume. With a GM tube you can cover even more, but the difference is not huge because of the geometry of the point source emission (the ends of the tube are far away compared to the center of the tube, if the source is near the center of the tube). With a distributed source, for example Fiestaware or Uranium glass, then the tube performs much better because every part of the tube is "close to the source" so to speak, whereas the scintillator is only close to part of the source. I am not sure if this explanation makes sense in words, but the point is that with a point source (which is what I tested in the beginning) the GM tube was better in detecting beta but it was not dramatic, like maybe 2x better, so to me this was not a major concern. With a distributed source such as Feistaware, or maybe mineral searching, then the difference is much bigger, GM tube is maybe 5x better or more. The Better Geiger can still identify beta sources, but if you are trying to search quickly for such objects then a GM tube will tell you much faster if something is radioactive or not. Overall for X-ray/gamma, which is most relevant for many applications, I think my detector is superior for all the reasons described on the web site.

Radiacode-101: I know in the eyes of some people here I am competing with the radiacode-101, but as I have said before I do not see these two devices as direct competitors. One is intended to be low cost and for more ordinary users, the other more high cost for more advanced users. Right now the radiacode-101 is about 3x the price of the Better Geiger. Most people who are interested in a radiation detector have no interest in spectroscopic information. Also, as of right now the radiacode-101 estimation of dose is extremely bad in my opinion, I don't know what algorithm they use but it very much overestimates lower energies (for a Cs-137 it's fine, though). If you have an unknown energy spectrum and you want a decent estimate of dose then this will cause problems. I guess they will sooner or later improve the firmware, but that's my experience right now. For measuring spectra it's a fantastic device, I have one and have enjoyed it very much. I expect both my detector and the radiacode will be popular in the future, and a person will choose one or the other according to their budget and interests. Some will even prefer a GM tube, for the reasons described earlier.

[Henri]

Beta measurement: The main thing I have learned between when I started the Kickstarter to now is that when measuring a source which is mainly beta and also distributed (not a point source) then the performance difference between my detector and a traditional GM tube is more than I originally thought. Generally with beta sources the area of the detector is extremely important, and because a scintillator is dense and small it is worse than a GM tube which is low-density and large. This I already knew, but with a point source the difference is not so dramatic because you can put the scintillator close to the source and cover a large solid angle even with a small sensitive volume. With a GM tube you can cover even more, but the difference is not huge because of the geometry of the point source emission (the ends of the tube are far away compared to the center of the tube, if the source is near the center of the tube). With a distributed source, for example Fiestaware or Uranium glass, then the tube performs much better because every part of the tube is "close to the source" so to speak, whereas the scintillator is only close to part of the source. I am not sure if this explanation makes sense in words, but the point is that with a point source (which is what I tested in the beginning) the GM tube was better in detecting beta but it was not dramatic, like maybe 2x better, so to me this was not a major concern. With a distributed source such as Feistaware, or maybe mineral searching, then the difference is much bigger, GM tube is maybe 5x better or more. The Better Geiger can still identify beta sources, but if you are trying to search quickly for such objects then a GM tube will tell you much faster if something is radioactive or not. Overall for X-ray/gamma, which is most relevant for many applications, I think my detector is superior for all the reasons described on the web site.

Hallo,

Danke für Deine offene und ehrliche Selbstbewertung!! Man sieht daran gut, dass es halt schwer ist, ein einzelnes Gerät zu bauen, das allen Messaufgaben gerecht wird. Dein BetterGeiger ist für die Messung von Gammastrahlung konzipiert. Wenn man Betastrahlung nachweisen möchte, braucht man idealerweise ein großflächiges Endfenster-Zählrohr. Möchte man Beta- und Gammadetektion in einem gemeinsamen Gerät vereint sehen, bedeutet das einen Kompromiss für beide Nachweise.

Ehrlich gesagt, ich finde es sogar gut, dass Dein Gerät so wenig Beta-sensitiv ist. In der Praxis hat man ja oft gemischte Strahlenfelder, und wie Du selbst schreibst, ist Dein Gerät für nicht so erfahrene Anwender konzipiert. Die machen dann häufig den Fehler, den Betaanteil nicht zu subtrahieren, und messen dann (mit dem Geigerzähler) viel zu hohe Werte. Sobald eine Dosisleistung (µSv/h) auf dem Display steht, sollte meiner Meinung nach der Betaanteil eh komplett ausgefiltert werden, damit es gar nicht erst zu diesen Mißverständnissen kommen kann. (Oder man hat einen "intelligenten" Abschirm-Schieber, der bei geöffneter Abschirmung im Display auf cps wechselt, oder weist beide Strahlenarten permanent getrennt nach, wie dieses eine Gerät von Radex).

Zum RadiaCode: es ist unglaublich traurig, aber ich kann mir nicht vorstellen, dass dieser als Gerät noch für den europäischen / westlichen Markt zur Verfügung stehen wird, und ich befürchte auch, dass die vielen schönen Update-Überraschungen für uns jetzt erst mal ein Ende gefunden haben. Russland wird ja wahrscheinlich auch aus den App-Stores geschmissen (??). Wer einen RadiaCode ergattern konnte, sollte gut drauf aufpassen, auch auf das zugehörige Smartphone...

Viele Grüße!

Henri


PS: wie hoch wären eigentlich momentan die Versandkosten nach Europa?

[BetterGeiger]

Beta measurement: The main thing I have learned between when I started the Kickstarter to now is that when measuring a source which is mainly beta and also distributed (not a point source) then the performance difference between my detector and a traditional GM tube is more than I originally thought. Generally with beta sources the area of the detector is extremely important, and because a scintillator is dense and small it is worse than a GM tube which is low-density and large. This I already knew, but with a point source the difference is not so dramatic because you can put the scintillator close to the source and cover a large solid angle even with a small sensitive volume. With a GM tube you can cover even more, but the difference is not huge because of the geometry of the point source emission (the ends of the tube are far away compared to the center of the tube, if the source is near the center of the tube). With a distributed source, for example Fiestaware or Uranium glass, then the tube performs much better because every part of the tube is "close to the source" so to speak, whereas the scintillator is only close to part of the source. I am not sure if this explanation makes sense in words, but the point is that with a point source (which is what I tested in the beginning) the GM tube was better in detecting beta but it was not dramatic, like maybe 2x better, so to me this was not a major concern. With a distributed source such as Feistaware, or maybe mineral searching, then the difference is much bigger, GM tube is maybe 5x better or more. The Better Geiger can still identify beta sources, but if you are trying to search quickly for such objects then a GM tube will tell you much faster if something is radioactive or not. Overall for X-ray/gamma, which is most relevant for many applications, I think my detector is superior for all the reasons described on the web site.

Hallo,

Danke für Deine offene und ehrliche Selbstbewertung!! Man sieht daran gut, dass es halt schwer ist, ein einzelnes Gerät zu bauen, das allen Messaufgaben gerecht wird. Dein BetterGeiger ist für die Messung von Gammastrahlung konzipiert. Wenn man Betastrahlung nachweisen möchte, braucht man idealerweise ein großflächiges Endfenster-Zählrohr. Möchte man Beta- und Gammadetektion in einem gemeinsamen Gerät vereint sehen, bedeutet das einen Kompromiss für beide Nachweise.

Ehrlich gesagt, ich finde es sogar gut, dass Dein Gerät so wenig Beta-sensitiv ist. In der Praxis hat man ja oft gemischte Strahlenfelder, und wie Du selbst schreibst, ist Dein Gerät für nicht so erfahrene Anwender konzipiert. Die machen dann häufig den Fehler, den Betaanteil nicht zu subtrahieren, und messen dann (mit dem Geigerzähler) viel zu hohe Werte. Sobald eine Dosisleistung (µSv/h) auf dem Display steht, sollte meiner Meinung nach der Betaanteil eh komplett ausgefiltert werden, damit es gar nicht erst zu diesen Mißverständnissen kommen kann. (Oder man hat einen "intelligenten" Abschirm-Schieber, der bei geöffneter Abschirmung im Display auf cps wechselt, oder weist beide Strahlenarten permanent getrennt nach, wie dieses eine Gerät von Radex).

Zum RadiaCode: es ist unglaublich traurig, aber ich kann mir nicht vorstellen, dass dieser als Gerät noch für den europäischen / westlichen Markt zur Verfügung stehen wird, und ich befürchte auch, dass die vielen schönen Update-Überraschungen für uns jetzt erst mal ein Ende gefunden haben. Russland wird ja wahrscheinlich auch aus den App-Stores geschmissen (??). Wer einen RadiaCode ergattern konnte, sollte gut drauf aufpassen, auch auf das zugehörige Smartphone...

Viele Grüße!

Henri


PS: wie hoch wären eigentlich momentan die Versandkosten nach Europa?

Yes, thank you, you have perfectly summarized many important points.

Even people with experience often do not understand that a dose number has no meaning when measuring beta, at that point like you say CPM is more appropriate. In the longer term I can imagine ways improve beta sensitivity, and maybe even alpha, but that means two sensitive elements inside and of course higher cost. Maybe something for the future, but probably getting spectroscopic information and/or bluetooth connectivity will be higher priorities, among other ideas.

As you say the radiacode will for sure be difficult to acquire in the near future. Like war, sanctions also have innocent victims. I hope in the longer term they will be able to continue development and sales, maybe some creative partnership with someone based in Europe or elsewhere.

Shipping to Europe and some other countries is $40, with USPS and supposedly takes 1-2 weeks. I do not know what extra delays will occur in each country due to their local authorities, and also what costs will be added there, those are unfortunately the responsibility of the buyer. I will also eventually explore local distributors, maybe even amazon.de , which might improve the situation.

[Na-22]

How do you calculate the doserate? Is it "countrate * calibration constant"?

[BetterGeiger]

How do you calculate the doserate? Is it "countrate * calibration constant"?

It is not a constant, it depends on incoming energy. It uses an algorithm I've developed myself.

[Henri]

How do you calculate the doserate? Is it "countrate * calibration constant"?

It is not a constant, it depends on incoming energy. It uses an algorithm I've developed myself.

Whow! So, finally - you do some kind of rough spectroscopy?? Nice!!

[DG0MG]

Links und rechts des "Menü"-Knopfes sind für Sound und Power zwei Schiebeschalter verbaut.
.. Die Schalter sind schnell ein Schwachpunkt, weil sie nicht ordentlich abzudichten sind (z.B. gegen Regen). Besser wären ausschließlich Taster.

Hier in diesem Video beschwert sich ein Mineraliensammler bei 1:15 min über einen "broken" Schalter, das ist also wirklich nicht das Optimum.