Skip to content


The GMC-500+ from GQ Electronics is a relatively inexpensive handheld geiger counter. One can be procured from Amazon Store Link. I have owned this for a short while and am relatively happy with the unit. For those new to monitoring, having a background reading is a must. If you wish to monitor things regarding the Chernobyl fire, it you will want to know what the normal background radiation levels are in your area to be able to tell if you are running into any issues due to that. Otherwise the standard cheat sheet is:

CPM uSv/h mR/h Action
5-50 0.03-0.33 0.003-0.033 Normal background.
51-99 0.33-0.65 0.033-0.065 Medium Level. Be alert
>100 >0.65 >0.065 High Level. Be alert and investigate why.
>1000 >6.50 >.650 Very High. Leave area ASAP and investigate why.
>2000 >13 >1.30 Extreme Levels. Evacuate and report to authorites.

Normal background readings can be found at the GMC Map.


Setup on Linux is pretty easy. Needs the application(s), wine, winetricks, and a working unit to plug into a USB port.

First you want to install the tools into a wine prefix of your choice. Goto their website (GQ Electronics LLC) and download the Data Logger PRO and/or Data Viewer.

Then we need to install them:

WINEPREFIX="/home/user/wineprefixes/gq-geiger" wine GQGMCDataViewer2.60.exe
WINEPREFIX="/home/user/wineprefixes/gq-geiger" wine GQGMGMCProSetup5.60.exe

After installation we need to use winetricks to add in a dll:

WINEPREFIX="/home/user/wineprefixes/gq-geiger" winetricks mfc42

And then we need to map the USB port to be accessible from the prefix:

ln -s /dev/ttyUSB0 /home/user/wineprefixes/gq-geiger/dosdevices/com2
sudo adduser <your_username> dialout

Now we can launch the programs as any other application and point the software to the proper COM port the unit is attached to, in our case COM2.


Data Viewer Screenshot