The Author and Publisher do not make any warranties
(express or implied) about the radiation information provided here for your use. All information provided should
be considered experimental. Safety and health issues and
concerns involving radioactive contamination should be
addressed, confirmed, and verified with local and national
government organizations or recognized experts in this field.
its trigger. The output pulse from the timer
flashes the LED and outputs an audible click
to the speaker via pin 3.
The alternative circuit’s components
(555 chip, caps, resistors) fit on a small
breadboard. You can connect it to one of the
main board’s digital outputs, or to where the
standard light and sound output connects
(LM339 pin 14), either replacing the original
output or making it switchable.
Digital Meter Adapter
You can do more with your Geiger counter by
wiring its digital output to a standard 3.5mm
mono earphone jack, connecting ground to
the sleeve contact and signal to the tip.
This output jack lets you connect the
meter to my company’s Digital Meter Adapter
(DMAD) an add-on that shows CPM or counts
per second (CPS) along with milliroentgens
per hour (mR/hr). Onboard switches also
configure the adapter to work as a true random number generator, with multiple ranges.
The DMAD (see inset, opposite) has a second
3.5mm plug for output, which lets you connect
any of its output functions to a computer via
3.5mm to RS-232 serial cable.
Juan Peña (Sparkfun)
Want to help keep track of radiation levels
nationwide? A 3.5mm output jack, as connected to the Digital Meter Adapter above,
will also let your Geiger counter become a
monitoring station for the Radiation Network
radiationnetwork.com), home of the National
Radiation Map. The network software is sold
with an adapter cable ($79 together). ;
For schematics and a template for an acrylic
More DIY Geiger Counters
By Paul Spinrad
1. USB Geiger Counter
SparkFun Electronics, $150
Has an onboard ATMega328 microcontroller
and a U.S.-made LND 712 Geiger tube (Figure
2b, page 105) that detects alpha, beta, and
2. MightyOhm Geiger Counter Kit
Maker Shed, $100
Solder-it-yourself kit includes ATtiny2313
microcontroller and Russian-made SBM- 20
Geiger tube that detects beta and gamma.
3. Radiation Sensor Board
for Arduino, with Geiger Tube
Libelium, € 115 ($163)
Currently includes China-made J305β
GM tube that detects beta and gamma,
but the board works with any tube in
the 400V– 1,000V range.
4. Grove Geiger Counter Module
Seeed Studio, $27 without GM tube
Works with Seeed’s $16 China-made
J408γ Geiger tube, which only detects
gamma radiation, or you can use any
other 400V tube.
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