There is something fascinating about an instrument that can detect
that which is invisible and undetectable to all human senses. Most Geiger counters
are analog circuits. This device is a microprocessor controlled portable Digital Geiger Counter (DGC)
as shown in the photo below.
The 500 volt DC G-M tube biasing voltage is generated by the MICROCHIP PIC in a
boost power supply configuration:
Display is menu driven with four line LCD digital readout;
Radiation measurements are date/time stamped by internal real time clock;
Microprocessor “sleep” mode is used to reduce power consumption;
Internal memory can store 125 radiation measurements using PIC18F2455, (375 using PIC18F2550);
Device has built-in USB interface for data upload to personal computer;
PIC firmware is written in freely available C language;
Personal Computer software is written in latest version of Visual Basic.Net; and
Device is pocket sized powered by four AA Lithium Hydride batteries (5 volts).
You can build this device yourself. Preprogrammed Microchip 18F2455 chips are available for $20. Contact me at rblang@comcast.net.
Thanks for visiting the site.