| T O P I C R E V I E W |
| ullix |
Posted - 12/20/2018 : 06:17:28
I routinely do look at other technology related to the Geiger field, and here is one which may be of interest to some readers, and may present an interesting opportunity for GQ.
An in-depth review is posted on my GeigerLog site under Articles as https://sourceforge.net/projects/geigerlog/files/Articles/GeigerLog-Review%20Smart%20Geiger%20Pro%20%28SGP-001%29-v.1.0.pdf/download so here is only a brief summary.
The “Smart Geiger Pro (SGP-001)” is a small detector for radioactivity designed to plug into the headphone plug of a smartphone. A radioactive event registered within the device is converted to an audio signal, which is fed into the microphone path of the smartphone. These “clicks” are counted by an app and presented graphically and numerically. It is available e.g. on Amazon for ~60€.
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Compared to a GMC counter with a M4011 tube, it is ~14 times less sensitive, but about 5 times more sensitive than a SI3BG tube, the famous 2nd tube in the 500+, and it is gamma-sensitive only.
One interesting feature is - and I hope that GQ takes note! - that it comes with a calibration certificate!
I am presenting some data comparing this SGP-001 to a GMC-300E+. They are on a par for some aspects, for others the GMC is ahead.
The measurement principle is NOT a Geiger-Müller tube, but is based on a PIN-diode. Those things are available for decades in nuclear labs to record high-resolution gamma spectra. But they come with a price tag of a mid-sized car!
This little SGP-001 or cousins of it won't come near that high-end laboratory equipment, but the opportunity that I see also for a company like GQ is the following:
The amplitude of the "clicks" generated in the device are proportional to the energy of the gamma quant, unlike in a Geiger-Müller counter.In other words, you can measure the amplitudes and create a gamma spectrum!
I imagine such a gamma spectrum being displayed on a counter. The current 128x64 dot display might be all you can achieve without cooling the device, but I do see this as a very attractive feature for a future counter variant!
To my knowledge, this does not exist (yet).
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| 4 L A T E S T R E P L I E S (Newest First) |
| ullix |
Posted - 12/28/2018 : 03:54:44
The same company is also manufacturing the GDK-101 device h**p://allsmartlab.com/eng/294-2/
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which seems to have everything the earplug-SGP-001 has missing, and the pulses are accessible.
Unfortunately, the sensitivity of this device, although nominally the same as the SGP-101, is very significantly lower than it, below the brink of usable.
And the pulses are lower in amplitude than claimed. Here is one of the better pulses, I think from an 1.4MeV gamma from K40.
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Disappointing.
But at least it demonstrates that the principle is viable.
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| ikerrg |
Posted - 12/25/2018 : 11:07:27
Interesting thought, ullix. That technology I think it is similar to the gamma spectrometer that a guy at my work uses to measure the isotopes' gamma emission (I already posted in this forum some data from that device some time ago for Am-241). That is a USB device, so I suppose that using the right electronics it is possible to do what you say to display the gamma spectrum of a radiation without the need for a PC and a USB connected gamma spectrometer. It is definitely a good idea for GQ to continue their development on radiation detectors, but I see much more complexity in the reading of amplitudes, calibration, etc. than in the simple event counters inside the GMC devices. Interesting for GQ's business development! |
| ullix |
Posted - 12/23/2018 : 03:07:15
Since you have the device and the Cs source - could you run a comparison between a) the Cs source directly, and b) the source with an beta-absorbing metal sheet in between? I ran a comparison with a Th source, and I get much lower counts with an absorber (1mm steel sheet).
I think it makes sense that the device has some beta sensitivity, as the copper + the black material + the plastic casing shouldn't be able to stop all high energy betas.
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| Stargazer 40 |
Posted - 12/21/2018 : 15:51:46
Have one of these. I like it very much. Here is a pic sitting on top of the 10uCi source for 10 min averaging
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and here on a 1 lb. bag of potassium salt
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As ullix says, lots of room for improvement and increased flexibility. Phone app really doesn't work well with this LG phone as it cuts off the calculated does rate.
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