SKU: 610708893875 Category:



ONYX is a next generation radiation detector, born from the international response to help communities affected by the Fukushima Daiichi reactor meltdowns.  Lead designer Bunnie Huang worked with Safecast, IMI and an international team to make it compatible with the Good Design Award Winning Safecast ecosystem, which has mapped and published over 60 Million radiation data readings since March 11, 2011.  Onyx can be used as a stand alone pocketable instrument, or it can connect to the internet and share data.  IMI has contributed design expertise, technology and backs the instrument with its standard industry best 2 year (1 year on GM sensor) warranty.  Onyx is produced at Medcom HQ in Sonoma County CA.

Note: The Safecast bGeigie Nano Kit is now available from Kithub.

ONYX features a modern, streamlined look and the use of advanced technologies, making it a one-of-a-kind Geiger Counter. It weighs only 7 oz. (200g.) and measures a mere 5.1 X 2.6 X 0.9 in. (72 X 37 X 13 mm.) making it easy to transport. Despite its compact size ONYX is capable of detecting alpha, beta and gamma radiation with the same sensitivity as the IMI Inspector Alert™, and like the IMI Inspector Alert™ V2, ONYX is optimized for surface contamination measurements through use of its 2 in. pancake Geiger Mueller tube.

The ONYX has a six button touch sensitive keypad that allows for easy use of a wide variety of functions such as graphic display of data, adjustment of audio chirp, data logging, changing units of measurement and calibration. ONYX also permits the user to upgrade the software running on the device to the latest version using a simple internet download feature. The version being shipped with the instrument is the most up to date.

Data are easy to read in a variety of formats ( µR/hr per hour, Counts Per Minute, µSv/h and Total Counts – with Timer) on the 128 X 128 color OLED display that measures 1.88 in. (47.9mm.) diagonally. In addition, ONYX is designed to share data through its micro-USB port.  Twitter data are transferred using QR code displayed on the OLED in combination with a smart phone with a QR Code scanner.

Please note that our Chrome IMI Gateway App is no longer available due to Google’s closure of the Chrome Store.  We apologize for any inconvenience experienced by our customers due to loss of that resource.  We are currently testing beta versions of  IMI Gateway for OS X and Windows.  For now you can upgrade your instrument using  IMI Gateway for Android.

Please use our Apps to keep your Onyx firmware up to date, to set time and date, to access your data, to continuously monitor radiation levels, and more.

If your Onyx software is v.12.26d or lower, or if you would like to upgrade your Safecast X Kickstarter instrument, please follow this link for information on how to upgrade.

View ONYX® Resources: Downloads, Operation Manual, Software, Firmware Updates

View ONYX®  Specification Flyer PDF



Detector: Halogen-quenched Geiger-Mueller tube. Effective diameter 1.75″ (45 mm). Mica window density 1.5-2.0 mg/cm²; Detects Alpha, Beta, Gamma, and X-radiation

Display: 128×128 color OLED (Organic Light Emitting Diode)

Operating Range: µSv/hr: .000 to 1,000::: µR/hr: .000 to 100,000 ::: CPM: 0 to 350,000

Accuracy: ± 10% typical; ±15% maximum

Alert Range: 0 to 99,999 CPM; Beeper sounds the alert when warning level feature is activated

Anti-Saturation: Readout holds at full scale in fields up to 100 times the maximum reading

Audio: Beeper chirps with each count when Geiger Beep function is activated

Averaging: Accumulate/Average feature builds average over time when activated

Certifications: CE Certified: Emissions: EN 55011:2009 + A1:2010 (Class B emissions limits); EN 61000-4-2:1995 (ESD); EN61000-4-3:1997. RoHS Compliant, Meets WEEE standards

Count Light: Red LED flashes with each count

Calibration: Cesium-137 (gamma from daughter metastable Barium)

Gamma Sensitivity: 334 CPM per µSv/hr (3340 CPM per mR/hr) referenced to Cs-137

Efficiency: For 4 pi at contact

Beta C-14 (49 keV avg. 156 keV max.): 5.3% Bi-210 (390 keV avg. 1.2 MeV max.): 32% Sr-90 (546 keV and 2.3 MeV): 38% P-32 (693 keV avg. 1.7 MeV max.): 33%

Alpha Am-241 (5.5 MeV): 18%

I-125:  Smallest detectable level for I-125 is .02 mCi at contact

Manual: ONYX Operation Manual

Options: USB cable, charger and carrying case available

Ports: Output: Stereo 3.5 mm jack sends pulses to headset or external data collection devices

Power: One 3.7 V Lithium Ion battery

Size: 130 x 660 x 230 mm (5.1 x 2.6 x 0.9 inches)

Temperature Range: -20º to +50º C , -4º to +122º F

Timer: Can set sampling periods of 1 minute to 40 hours.

Weight: 200 grams (7 oz) including battery


International Medcom is passionate about quality and customer satisfaction. We provide the best radiation detector warranty available anywhere.

This product is warranted to the original owner to be free from
defects in materials and workmanship for two years from the
date of purchase with the exception of the Geiger-Mueller tube,
which is warranted for one year. The battery is not included
in this warranty. International Medcom, Inc. will, at its own
discretion, repair or replace this instrument if it fails to operate
properly within this warranty period provided that it has not
been subjected to misuse, abuse, or neglect. Modification or
repair of this instrument by anyone other than International
Medcom, Inc. voids this warranty.

Contamination of this instrument with radioactive materials
voids this warranty. Contaminated instruments will not be
accepted for servicing at our repair facility.

The user is responsible for determining the suitability of this
product for the intended application. The user assumes all risk
and liability connected with such use. International Medcom,
Inc. is not responsible for incidental or consequential damages
arising from the use of this instrument.

The terms of this warranty are subject to change without notice.