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 2.GQ Geiger Muller Counter
 GMC-800 Concerns
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jeff_becker@msn.com

USA
9 Posts

Posted - 11/15/2023 :  08:13:04  Show Profile  Reply with Quote
I just purchased the new GMC-800 for safety in the event of a nuclear exchange, dirty bomb or accident, after holding off on purchasing the GMC-600+ due to its poor/dated interface and apparent fragile case. I have not had any problems with the GMC-800, but I have no way of knowing its actual accuracy and response time in measuring radiation. I have been concerned with its accuracy and performance due to its very low price. Just yesterday I read the Amazon review of the GMC-800 (listed below) and I am now very concerned that I made a bad decision. Any thoughts?

Scarlyn
1.0 out of 5 stars Too good to be true, very disappointed.
Reviewed in the United States on November 11, 2023
Verified Purchase
I am a Chemistry PhD. student currently working in a lab with radioactive materials.
Long story short: I wanted to buy a personal Geiger counter for me to take home, but that it can also function properly in the lab.
I found the GQ GMC-800 very appealing because of the display and price. But it was too "cute" to be true.

When I received it, I was home, so I couldn't test it properly. The reading was an average of 12 to 20 CPM (background radiation)
The next day at the lab, I took it near the fume hood, where normally our Ludlum survey meter goes crazy, but the GQ GMC-800 stayed the same,
nothing happened. I was getting background radiation levels on the GMC-800. So we tested it by putting it on top of a Uranium glass and leaving it there,
and after about 15 minutes, we got a max reading of 80 CPM, compared to our other devices (including the ludlum), which immediately went up to 300 CPM
on the same Uranium glass.

Now that's not good at all! And even if it was only my device that came defective, it makes me wonder about the overall quality and reliability of this GQ GMC-800. I'm really disappointed.
So, I'm returning this one for sure.
Reply #1

ullix

Germany
1107 Posts

Posted - 11/16/2023 :  01:19:54  Show Profile  Reply with Quote
I'd be surprised if the GMC-800 were as bad as you say. I suspect it is more a lack of understanding of measurements!

Most often the cause is comparing two instruments where one is - by its design - more sensitive to betas than the other, and the rdioactive source being rich in betas.

I have not had a GMC-800 in hand, but by the pictures of it it looks like having a more sturdy case than its older GMC siblings. If true it would mean that its sensitivity to betas is further reduced.

A good reference to compare counters is KCl, as its radioactivity, while weak, is the same everywhere on earth. It is emitting betas more stronger than gammas.

I suggest my "Potty Training" article, which has the details; download from: https://sourceforge.net/projects/geigerlog/files/Articles/

It involves removing the backplate of the counter to expose the "naked tube" to the KCl source.
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Reply #2

ihab17

Italy
212 Posts

Posted - 11/16/2023 :  03:24:35  Show Profile  Reply with Quote
The GMC-800 detects Beta and Gamma, but not Alpha particles as far as I know. Uranium decays into Thorium by emitting an Alpha particle which your GMC-800 can't detect. If you want to detect Alpha particles, your only GMC solution is the GMC-600+

Edited by - ihab17 on 11/16/2023 08:35:11
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Reply #3

EmfDev

2143 Posts

Posted - 11/16/2023 :  15:26:56  Show Profile  Reply with Quote
The review is either from a competitor or a lack-of-radiation-knowledge-PhD-student-who-will-soon-fail-his-degree:). THE GMC-800 has passed the USA NRC/NIST Calibration standard. This guy is comparing a pancake tube and a ~$1000 detector to an entry level geiger counter that cannot detect alpha. Instead of comparing the uSv/h, he even instead compared the CPM.
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Reply #4

jeff_becker@msn.com

USA
9 Posts

Posted - 11/17/2023 :  10:39:23  Show Profile  Reply with Quote
You are missing my point. If a $1,000 Geiger counter and one that also detects Alpha radiation is what is needed to protect me and allow me to greatly reduce my chances of a level of exposure high enough to impact my health in the event of 1) a nuclear accident, 2) dirty bomb or 3) a nuclear exchange/war between the US and another nuclear power, the price of the Geiger counter is irrelevant. I made my post stating that I was considering the GMC 600+ (which measures alpha) and am willing to pay whatever price is necessary (within reason) to meet my stated requirements. I also stated that I was concerned that I paid too little for the GQ GMC 800 and was "concerned with its accuracy and performance due to its very low price." If a Geiger counter costing $600 to $1,000 is what is needed to meet my requirements, I am willing to pay that. However, if I don't need to pay that amount to meet my requirements, I don't want to unnecessarily waste money either.
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Reply #5

EmfDev

2143 Posts

Posted - 11/17/2023 :  13:45:07  Show Profile  Reply with Quote
The GMC-800 is good choice for your purpose. If any of those events you listed happened, the radiation will be much higher. The GMC-800 will be able to pick up the radiation.
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Reply #6

ullix

Germany
1107 Posts

Posted - 11/18/2023 :  01:52:51  Show Profile  Reply with Quote
quote:
The GMC-800 is good choice for your purpose. If any of those you event listed happened, the radiation will much higher. The GMC-800 will be able to pick up the radiation.

I concur.

And read the "Chemistry PhD. student" report carefully - lots of indications that this guy is lacking competency!

And after all, even better than a Geiger counter for your purposes is a battery powered radio.
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Reply #7

UnstableIsotope

USA
67 Posts

Posted - 12/05/2023 :  14:58:48  Show Profile  Reply with Quote
quote:
Originally posted by EmfDev

The review is either from a competitor or a lack-of-radiation-knowledge-PhD-student-who-will-soon-fail-his-degree:). THE GMC-800 has passed the USA NRC/NIST Calibration standard. This guy is comparing a pancake tube and a ~$1000 detector to an entry level geiger counter that cannot detect alpha. Instead of comparing the uSv/h, he even instead compared the CPM.



I read that same review on Amazon and thought the same thing.
Really? This self-impressed PhD student apparently doesn't know that the Ludlum will pickup Alpha while any glass tube device will not. Doh!

Frankly, I really hope the GQ 800, at least in terms of it's more pro looking, and hopefully more durable, exterior is the way GQ continues to move it's product line.

I already had a couple cheap Geigers before I picked up the 500+. While neither compete with the 500+ in terms of features and functions, the FNIRSI GC-01 presents an up-to-date, professional design with a very responsive UI, great screen, etc. Too bad it's locked into a 10s sliding averaging window that causes it to overshoot background estimates by quite a bit. The FNIRSI also oddly omits an audible click feature instead indicating individual events only on an LED.

I sincerely hope GQ will continue to update it's aesthetics and usability for new products. I honestly considered the 800 before purchasing the 500+ purely for technical reasons. I really wish the 500+ was packaged like the 800.

Edited by - UnstableIsotope on 12/06/2023 06:17:36
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Reply #8

ihab17

Italy
212 Posts

Posted - 12/06/2023 :  06:57:34  Show Profile  Reply with Quote
quote:
Originally posted by UnstableIsotope

I already had a couple cheap Geigers before I picked up the 500+. While neither compete with the 500+ in terms of features and functions, the FNIRSI GC-01 presents an up-to-date, professional design with a very responsive UI, great screen, etc. Too bad it's locked into a 10s sliding averaging window that causes it to overshoot background estimates by quite a bit. The FNIRSI also oddly omits an audible click feature instead indicating individual events only on an LED.

I sincerely hope GQ will continue to update it's aesthetics and usability for new products. I honestly considered the 800 before purchasing the 500+ purely for technical reasons. I really wish the 500+ was packaged like the 800.



Personally, I wouldn't go for this cheap Chinese product (FNIRSI GC-01), with extreme commercial (non-scientific) idiotic and childish marketing. Here is the official link which you can find also on AliExpress or AliBaba. Scroll down until you the the image in Nuclear Radiation Dose Hazards at a Glance... they measure the dose by RUM!!!! Rum? Vodka? Or did they mean REM? If they don't even know how to write the scientific unit, go figure if I even accept a device like this even if it was a gift! The word measuring becomes mea-suring! Come on! It is a toy, you can't trust it!

https://usa.banggood.com/FNIRSI-GC01-Geiger-Counter-Nuclear-Radiation-Tester-Food-and-nuclear-sewage-Test-Professional-Marble-Radiation-Ionization-Personal-Dose-Alarm-Radioactive-Tester-p-1973818.html?imageAb=2&akmClientCountry=IT&cur_warehouse=CN&a=1701873419.1607&DCC=US¤cy=EUR&akmClientCountry=IT

For me, a Geiger Counter is a scientific instrument, and if you need a good one, you have to spend money, especially if you have the need to detect Alpha particles. A scientific instrument does not have to be appealing esthetically, it simply has to work and do what it is supposed to do. The esthetics comes much later after the product has been tested and demonstrates reliability and accuracy. GQ instruments aren't esthetically appealing as this one above, and they might not be reliable and accurate as a 2K euro/dollar professional device, but at least you have the possibility to write here on their forum, get firmware updates, and ask questions. Try doing that on ALiExpress or directly to the Chinese manufacturer... good luck with that!
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Reply #9

ihab17

Italy
212 Posts

Posted - 12/06/2023 :  06:58:20  Show Profile  Reply with Quote
quote:
Originally posted by UnstableIsotope

I already had a couple cheap Geigers before I picked up the 500+. While neither compete with the 500+ in terms of features and functions, the FNIRSI GC-01 presents an up-to-date, professional design with a very responsive UI, great screen, etc. Too bad it's locked into a 10s sliding averaging window that causes it to overshoot background estimates by quite a bit. The FNIRSI also oddly omits an audible click feature instead indicating individual events only on an LED.

I sincerely hope GQ will continue to update it's aesthetics and usability for new products. I honestly considered the 800 before purchasing the 500+ purely for technical reasons. I really wish the 500+ was packaged like the 800.



Personally, I wouldn't go for this cheap Chinese product (FNIRSI GC-01), with extreme commercial (non-scientific) idiotic and childish marketing. Here is the official link which you can find also on AliExpress or AliBaba. Scroll down until you see the image in Nuclear Radiation Dose Hazards at a Glance... they measure the dose by RUM!!!! Rum? Vodka? Or did they mean REM? If they don't even know how to write the scientific unit, go figure if I even accept a device like this even if it was a gift! The word measuring becomes mea-suring! Come on! It is a toy, you can't trust it!

https://usa.banggood.com/FNIRSI-GC01-Geiger-Counter-Nuclear-Radiation-Tester-Food-and-nuclear-sewage-Test-Professional-Marble-Radiation-Ionization-Personal-Dose-Alarm-Radioactive-Tester-p-1973818.html?imageAb=2&akmClientCountry=IT&cur_warehouse=CN&a=1701873419.1607&DCC=USĄcy=EUR&akmClientCountry=IT


For me, a Geiger Counter is a scientific instrument, and if you need a good one, you have to spend money, especially if you have the need to detect Alpha particles. A scientific instrument does not have to be appealing esthetically, it simply has to work and do what it is supposed to do. The esthetics comes much later after the product has been tested and demonstrates reliability and accuracy. GQ instruments aren't esthetically appealing as this one above, and they might not be reliable and accurate as a 2K euro/dollar professional device, but at least you have the possibility to write here on their forum, get firmware updates, and ask questions. Try doing that on ALiExpress or directly to the Chinese manufacturer... good luck with that!

Edited by - ihab17 on 12/06/2023 07:00:05
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Reply #10

Jadeye

34 Posts

Posted - 12/06/2023 :  07:54:11  Show Profile  Reply with Quote
@ihab17: I like how the alarm modes are translated as "glitter" and "shock", it could be an interesting experience, if the "glitter" would sprinkle the user with glitter, and the "shock" would deliver an (electric) shock. :D
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Reply #11

ihab17

Italy
212 Posts

Posted - 12/06/2023 :  09:33:32  Show Profile  Reply with Quote
quote:
Originally posted by Jadeye

@ihab17: I like how the alarm modes are translated as "glitter" and "shock", it could be an interesting experience, if the "glitter" would sprinkle the user with glitter, and the "shock" would deliver an (electric) shock. :D



Not to mention the word Symptoms becomes Sympatoms
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Reply #12

UnstableIsotope

USA
67 Posts

Posted - 12/06/2023 :  09:55:06  Show Profile  Reply with Quote
quote:
Originally posted by ihab17

quote:
Originally posted by UnstableIsotope

I already had a couple cheap Geigers before I picked up the 500+. While neither compete with the 500+ in terms of features and functions, the FNIRSI GC-01 presents an up-to-date, professional design with a very responsive UI, great screen, etc. Too bad it's locked into a 10s sliding averaging window that causes it to overshoot background estimates by quite a bit. The FNIRSI also oddly omits an audible click feature instead indicating individual events only on an LED.

I sincerely hope GQ will continue to update it's aesthetics and usability for new products. I honestly considered the 800 before purchasing the 500+ purely for technical reasons. I really wish the 500+ was packaged like the 800.



Personally, I wouldn't go for this cheap Chinese product (FNIRSI GC-01), with extreme commercial (non-scientific) idiotic and childish marketing. Here is the official link which you can find also on AliExpress or AliBaba. Scroll down until you see the image in Nuclear Radiation Dose Hazards at a Glance... they measure the dose by RUM!!!! Rum? Vodka? Or did they mean REM? If they don't even know how to write the scientific unit, go figure if I even accept a device like this even if it was a gift! The word measuring becomes mea-suring! Come on! It is a toy, you can't trust it!

https://usa.banggood.com/FNIRSI-GC01-Geiger-Counter-Nuclear-Radiation-Tester-Food-and-nuclear-sewage-Test-Professional-Marble-Radiation-Ionization-Personal-Dose-Alarm-Radioactive-Tester-p-1973818.html?imageAb=2&akmClientCountry=IT&cur_warehouse=CN&a=1701873419.1607&DCC=USĄcy=EUR&akmClientCountry=IT


For me, a Geiger Counter is a scientific instrument, and if you need a good one, you have to spend money, especially if you have the need to detect Alpha particles. A scientific instrument does not have to be appealing esthetically, it simply has to work and do what it is supposed to do. The esthetics comes much later after the product has been tested and demonstrates reliability and accuracy. GQ instruments aren't esthetically appealing as this one above, and they might not be reliable and accurate as a 2K euro/dollar professional device, but at least you have the possibility to write here on their forum, get firmware updates, and ask questions. Try doing that on ALiExpress or directly to the Chinese manufacturer... good luck with that!




Agreed, their English is lacking, but still much better than my Mandarin. It was the first GC I picked up for grins and while the marketing is sketchy, the product design appears to be reasonably sound. Also, within the limits of it's 10s estimation window and an unvented case, the GC-01 appears to function as expected. The PCB layout is clean and well done. The case is well designed with a full silicone bumper surrounding the edges which would absorb small bumps and drops instead of transmitting that energy to the fragile GM tube. The display is excellent and updates quickly. It even comes with a nice, bubble-free screen protector installed! The interface is also very responsive. These are all good things that every product like this should have as design goals.

While my 500+ is much more a real instrument, it doesn't have to lack the characteristics I list above to be so. The GC user interface is very dated and honestly pretty bad in some areas. Menu items are inconsistently implemented and some are very cumbersome, like entering a Wifi password or changing a CPM alarm or the MEDIUM/HIGH thresholds. Some menu items are grammatically incorrect as well. The buttons are not properly polled and respond inconsistently. These things could be improved while still remaining a more accurate measuring instrument.

I really like all the fine-grained, nerdy adjustments that are available on my 500+. The level of control is wonderful compared to simple devices. However, all these features should be consistently implemented to produce an intuitive and responsive user interface. At this point, that is not the case.

Edited by - UnstableIsotope on 12/10/2023 10:09:10
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