19. October 2016 · Comments Off on Graphing radiation with a GMC-320 geiger counter using Cacti · Categories: Cacti, Linux, Linux Scripts

A few years ago, right after the Fukushima Daiichi nuclear disaster, XKCD released an awesome Radiation Dose Chart. Also around that time portable geiger counters became much easier to get a hold of and fairly cheap. Me being a data nerd; I researched a variety of devices and decided to get a CQ GMC-320. Its an awesome portable geiger counter that has a USB data-port on it that allows you to collect the CPM via a USB serial port. The following Cacti template and Python script is how I generated the following Graph.


Additional GMC-320 Links

This Cacti template will import/update the following items:


  • Trend
  • Geiger – sV [ALL]
  • Geiger – sV [AVG]
  • Geiger – mR [ALL]
  • Geiger – mR [AVG]


  • Normal
  • Exact Numbers
  • MicroSievert
  • Interger
  • MilliRoentgen

Data Input Method

  • GQ – GMC-320Re 3.22

Data Template

  • GQ – CPM

Graph Template

  • GMC-320 – CPM values