The GC-20 is a portable Geiger counter, dosimeter and Radiation Monitoring Station all-in-one!

This compact device is the result of many improvements made on my previous Geiger counter that started as a hobby project. The GC-20 is much smaller, while keeping the same large touchscreen display, and adds many modern software functionalities to complement its clean and intuitive GUI. Some of the main features are:

• Touchscreen controlled, intuitive GUI
• Displays counts per minute, current dose, and accumulated dose on homescreen
• Sensitive and reliable SBM-20 Geiger-Muller tube
• Variable integration time for averaging dose rate
• Timed count mode for measuring and comparing low doses
• Choose between Sieverts and Rems as the units for the displayed dose rate
• User adjustable alert threshold
• Adjustable calibration to relate CPM to dose rate for various isotopes
• Audible clicker and LED indicator toggled on and off from homescreen
• Offline data logging
• Post bulk logged data to cloud service (ThingSpeak) to graph, analyze and/or save to computer
• Monitoring Station mode: device stays connected to WiFi and regularly posts ambient radiation level to ThingSpeak channel
• 2000 mAh rechargeable LiPo battery with 16 hour run time, micro USB charging port
• No programming required from the end user, WiFi setup handled through GUI

Use the GC-20 to detect ionizing radiation from Uranium ore, fiestaware, radium-coated watch hands, vaseline glass, and many other sources! A portable Geiger counter makes it easy to see if the cool rock you found has Uranium or Thorium ore in it. With its Timed Count feature, the GC-20 can even be used to detect high levels of Radon. With the Monitoring Station feature, the GC-20 can be used as an always-on radiation monitoring station that connects to your WiFi and logs ambient radiation data to a free-to-use cloud service (ThingSpeak).

The modern design and ease of use of the GC-20 sets it apart from the commercially available consumer-grade Geiger counters. Find all software features in just a few taps with the sleek and clean touchscreen display. No more navigating through a clunky, dated user interface with limited input options that has a learning curve.

The device is also fully open-source with all code and hardware design files available in the GitHub page linked below. Also find the user manual and additional information by clicking on the "Documentation" button.

Note: The device comes fully assembled, and includes the rechargeable battery. A micro-USB cable and a charging adapter (such as a phone charging brick) are needed to charge the battery, and are NOT INCLUDED.