GQRadiation Detector Dosimeter, GMC-600 Plus, Battery Powered, Wi-Fi Connectivity and Data Logging, High Sensitive, Alpha, Beta, Gamma, X-ray, Lithium-Ion

Very sensitive geiger counter works excellent on alpha radiation thanks brian.

Detector works as described, very satisfied

I have had mine for a few months now. I got it more out of curiosity than anything else. It has performed well and battery life is great. I monitor background and checked out an old Pentax lens I have that I know has a radioactive rear element. A lot older lenses made from the 1940's through the 1970s used thorium oxide. Quite a surprise how much radiation the rear element puts out at it's surface.The lens above measures 250 CPM at the front element and about 130 CPM behind the camera when the lens is mounted on it. Most radiation is gone by the time you get about 3 feet (1 meter) from the lens with reading jsut a little higher than normal background. .

The media could not be loaded. Works great up untill 22k counts then unit starts detecting an unreasonable jump in counts 100k or so and the unit stops responding after removed from the test source still reads. Samples is ore in epoxy sealed in plastic bag, units not contaminated it resets to normal after a restart. Scan the sample again crashes. Not impressed as the unit is rated for 1M counts per minute. I'm not sure if this is normal for the unit but I would hope not.I've reached out to tech support and they have responded, and will be sending me a firmware update. I will report back.Update support has been amazing so far, including sending me a custom firmware update. I didn't work but I am in the process of filing an exchange I'll update when done.

Working exceptionally well out of the box will update as time goes byCould use a protective rubber boot hate the idea of dropping it

The GMC-600 plus is a very good Geiger counter. It has a LND 7137 2” pancake tube which is the most sensitive 2” tube I know of. The tube is $200 by itself. This tube is sensitive to Alphas, as well as the usual Beta and Gamma of most Geiger tubes. The battery lasts forever (days).I pinged it for accuracy as the 10 and 15 second average modes seem to be erroneous and GQ support has not responded to multiple requests asking for access to an updated firmware that based on their own forum exists.They claim to sale and support from the USA, however based on the obvious grasp of English they are not.

The ability to detect alpha radiation is a big plus,and is quite sensitive.The case the meter is housed in is another story,I have never seen such a poorly constructed case from what looks like recycled plastic,with a battery cover that could snap off at any moment,You wouldn't want to drop this meter because it wouldn't survive.

The media could not be loaded. Having the ability to measure Alpha radiation is a plus. In the video you can see a 6" pvc end cap blocking most of the Beta coming off my pile of radioactive things. From about 5" away when I lift the cap, the reading reaches the same level my GMC-500 reads sitting right on top of this stack! At this distance it is not picking up much Alpha. When placed on top it reads over 60K CPM.I did have a problem a couple of weeks ago. The unit died while taking some measurement watching the decay rate of Pb 214 and Bi 214, daughter products from Radon decay. See graph picture for results. I emailed GQ and they gave me an RMA and I sent the unit back. After a week it's on it's way back and it cost me $30 plus shipping. They were very responsive and answered some of my other questions.If the transistor hadn't died I would have given this unit 5 stars. Transistors mostly fail because of high junction temperature and the temperature might have been caused by reading over 10K CPM for over 10 minutes. Hopefully not a design issue and just a one time failure.