Faulty GMC 500+ Geiger Counter
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- Опубликовано: 17 окт 2024
- Odd issue with my GMC 500+
*Update 5/5/21....
I eventually got updated firmware for the unit from GMC but it made no difference. After a bit more fault finding it has been confirmed that the high range tube is faulty. I will eventually replace it with a Soviet GM tube.
That sample is insanely radioactive, I've never heard a geiger counter click that fast!
Hi, just for sake of curiosity: what happens in presence of a normal radiactivity background with default two tubes mode if hypotetically the high sensitivity tube is broken ? The firmware forced to use the low sensitivity tube only (that for high levels of radiations) will render cpm levels apparently too low, or the firmware is able to report a malfunction without showing levels lower than reality ? Thanks.
Hello, Thank you for this video. I received mine 2 months ago and returned it (Amazon). Because instead of specifying, for example, that you should not activate the 2 tubes or that you should only activate the weak or the powerful one, they simply removed the small tube for high radiation including the welded parts that fix it! They should have specified it by putting 'version limited to low radiation' and sold it but nothing was specified and the price was always the same. Disappointed and I hope I find a multi tube detector to calibrate high radiation because wherever there is a nuclear accident/pollution, people who have detectors complain that they are useless because they saturate well before approach a strong source of radioactivity and therefore it is impossible to locate/avoid it.
What do you thing about this one ? thinking tok get it but I dont know which one should be good to buy some thing cheap. Thanks
Maybe it automaticaly close the low tube at a certain level and switch to the high tube only. Did you try putting the source nearer the high tube when it goes low?
The high level tube was broken. It was confirmed by GQ.
Is that maybe the phenomenon know as 'maxing out the tubes'? When a device encounters levels higher than it's rated for instead of displaying the maximum level the device is capable of reading, it will instead read low.
For example, say some random counter maxes out at 450 uSv/hr. Expose it to 449 uSv/hr source and it will display 449 uSv/hr...however, expose it to 551 uSv/hr and it suddenly will be claiming 10 uSv/hr or even 0.
Not all counters do that and not all of them max out in the same way, but many of them do respond to maxing out but giving a waaay low reading.
This counter has two tubes, a low/mid range and a high range. Once its reaches a certain level it is supposed to switch from the 1st to the 2nd tube. In this case, the 2nd tube is faulty, so the switching never happens.
@@SurvivingTheApocalypse I see. I actually have the same counter but I'm just getting into this stuff so my knowledge is a bit lacking.
Are you sure it isn't switching the tubes? I just took out my 500+ and grabbed my weak little baby source (3000 CPM that gets ~3000CPM/20 uSv/hr expected on 'sensitive' tube...but when I put the source near the 'high range' tube I'm at about 150/cpm, 1 uSv/hr.)
I'm not too familiar with how the high-sensitivity vs high-range tubes work...but looking at that I might guess if you're switched to high range you would multiply whatever the readout is by twenty to get the real value (as 150x20 cpm = 3000 (expected, and 1usv/hr = 20 usv/hr (expected).
If you were to multiply the readout values after it drops down...would that get you close to the expected result?
(I know - if it works that way it's seriously janky 'cause it wouldn't be too hard to program in corrections for the high range tube reading, and maybe the fact that the arithmetic works out in that my sensitive tube = high range tube x 20 is a coinicidence...but now I'm curious! =))
@@angry_zergling hei dude i have the same geiger counter as yours the GMC-500+, i tested it into normal enviroments and i have 0.25 uSv reads with the tube 1(more sensitive) while if i manual switch to the tube 2 i have a steady 0 CPM and 0 uSv and rarely it shows 1 CPM and 0.40 uSv in the same natural enviroment of my house, do you think the tube 2 is broken? or it is too much "fat" to catch low emitting natural sources like the tube 1 does? Please help me cause I will return it if it is not a normal behaviour!
Superb review, is the GMC500 worth buying over the GMC300?
I can't find ANY back to back reviews anywhere and your video is the closest I've come to answering my "which is better and is the second tube worth the purchase price?"
Thank you.
Reliability wise its great, I have had mine switched on for over a year and its updating radiation levels to a server every 20mins. Other than the faulty tube (which has now been replaced) I have had no further issues with it.
I think simply for the extra features its worth buying the 500 over the 300.
The biggest difference is wifi. Makes a huge difference for updating gmcmap as a standalone unit.
Just an update to this, had this for 2 years now and its still working fine. Its been switched on constantly during that time.
As far as I am aware (and correct me if I'm wrong), CONTINUOUS exposure to 50 mSv/hour is Dangerously HIGH, even if the unit gets tangled-up in its overwhelmed calculating underwear where the actual mSv/hour is, say 1000 mSv/hr. Assuming that is true, then whether the unit is or is not overwhelmed or functioning as one would expect is basically a moot point.
I believe the hardware part of the counter might not be able to handle more than a number of counts per second before rolling back over to zero. I don't have this particular model and I don't have a powerful enough source but I've been wanting to test my GMC 600 about that too. As a bit of trivia, once the GMC 320 gets over 65535 counts per minute(~340 uSv/h) it too rolls back over to zero.
Interesting, thanks for this. Turning off the high range tube definitely fixes the issue for me but also means I have no longer got a high range tube!
@@SurvivingTheApocalypse I have the GMC-320+ and the GMC-600 sadly I do not also have the GMC-500 or I would have checked for you.
Searinox Navras I very nearly got a 600+ recently but in the end I got a Radiascan 701A.
Andreas Jack big delay in postage at the moment due to Covid-19. I am waiting on 4 geiger counters arriving currently.
Andreas Jack definitely going to be doing reviews on the new ones, two of them will probably be more of a ‘buyers guide’.
As for Chernobyl. Not sure to be honest. All travel to Ukraine from the UK is forbidden at the moment and I have no idea when those restrictions will be lifted. I still really hope I can go, its at the end of May so a lot can change!
I just bought one of these. It makes a rattling noise inside, almost like a broken light bulb. Seems to be coming from the gieger tube. Is this normal?
The tube does make a bit of noise but as long as you don’t really go to town on it or drop it repeatedly then it will be fine. Quite a lot of people replace the glass tube with an SBM-20.
@@SurvivingTheApocalypse Thanks for the quick reply! You've got some great videos. I'll look into changing it!
Can someone share video or picture of graph view when there is gaama radiation on 600+ / 500+
Swapping the big tube with an SBM20 would help?
I bought one of these...it didn't come with the glass tube...what the?! Only one tube, the clip fir the second one is empty.
Hey how's it going I just found your RUclips channel. Good vids... I was wondering if you had any update on this Geiger counter if it was a firmware problem or maybe hardware?
Pretty sure its hardware related as I received the latest firmware from GQ and it didn’t make any difference. I think the high range tube is either faulty or totally broken.
@@SurvivingTheApocalypse thanks for getting back to me... I was thinking about getting one of these.Do you think it was just yours or do you think this is a problem with all of them?
I have owned 2 of GQ meters and they are decent quality software wise but the build quality is fairly cheap. I have been a member of their online user forum for a few years and the 500+ does seem to be pretty reliable. Clearly mine is just in a small handful of faulty units.
@@SurvivingTheApocalypse ok cool... thanks
Great video. What is that device that you have that puts off radiation? Thanks
It is a radium painted display from a 1950’s wind speed meter. Video of it in more detail is here :- ruclips.net/video/zHEJFvAYU_g/видео.html
@@SurvivingTheApocalypse Thanks for the quick response. I just found your channel today and subscribed. I've been binge watching all your videos today.
How do you swap whoch tube is on?
In the settings under ‘initial setup’, then ‘tube settings’ and then finally ‘tube selection’.
maybe something to do with the automatic voltage increase it does with the tubes?
Not work, but after manually increasing the voltage in 500 and 500+ to 50%, I obtained the full performance of the dosimeter. This problem does not occur with the GMC-600 version
wtf man :D i didnt expected that 1 mSv.. what is it?
Its a wind speed gauge (anemometer) from the 1950’s. The dial is painted with radium.
@@SurvivingTheApocalypse wow
Which software version did you use?
The latest version. GQ emailed it to me.
Surviving The Apocalypse thanks. I have 2.19 but they don’t respond to my email. I have send them the serial of my device.
Are you a member of their user forum? If your not then I would make a point of joining it.
Surviving The Apocalypse I am a member...
I think it took about a week to get the email from them.
What's happening is it's designed so that it keeps only the low range tube on until it reaches saturation then the computer automatically switches to the high range tube when a more intense energy source is detected. When that happens the second tube is energy compensated and farther away from the radiation source and so naturally it's going to read lower. SO No it's not broken it's working as designed.
It was broken mate, the company confirmed it was broken, the company replaced the faulty tube.
Hi, your firmware version? :) thanks
Its running the latest firmware (as of July 2020). I contacted GQ Electronics and they emailed it to me. Out of the box it was running Re.2.20. They sent me a new tube but I am yet to fit it.
@@SurvivingTheApocalypse Thanks! new GM tube m4011? si3bg?
@@SurvivingTheApocalypse My GMC-500 and 500+ almost stopped measuring at 1 R/h, I had to manually increase the voltage to 50%. Both use Re 2.25
I think that was one of the first things I tried doing, but it made no difference.
The new tube is in a box ‘somewhere’, I must have a look for it. I have my 500+ powered on 24hrs a day and transmitting live data to the GMC geiger counter world map site.
@@SurvivingTheApocalypse It sounds amazing :) Tomorrow I am picking up the older GMC-300E Plus.
Glad you got it repaired. I bought one and had no problems with it. Watching the video I could see it was not reading correctly. Did you make another one with the repaired counter?
No I didn’t get around to it actually. I ‘think’ it works correctly lol. The glass tubes they use are not very good to be honest.
You saturated the tube.
There are two tubes, a low/mid range and a mid/high range. The high range tube was broken and it was replaced by GQ Electronics under warranty and its working properly now.