RadioactivityCounter

The App is available in the App Store !

This iOS application is a real working radioactivity counter without any extra hardware needed ! Just cover the lens with a black paper and tape it there (Must be tight and light proof - don't put glue on the camera lenses!). It will turn your phone into a Geiger Mueller Counter to measure radioactivity after proper calibration.

Important note: The camera sensor can measure gamma radiation (CS137 for example) and some beta radiation (depends on the energy if the beta rays can pass through the plastic parts - for example H3 or K14 are weak sources). It cannot measure alpha rays (like PO210...). We will give more infos here and prepare an instructional video on the usage.

We did calibrations with several iPod2, IPhone 3GS, iPhone 4, iPhone 4S , iPad 2, Ipad3 and iPhone 5..X (now available in 2.2) devices at the Helmholtz Research Centrum, Munich (thanks to Prof. Dr. Christoph Hoeschen). We used a CS137 test source from 10 µGy/h till 1 Sv/h for each of the phones we had in the so called Buchler device, used for example for dosemeter calibration. The values are stored as a rough start on the application (all devices differ a little bit). For precise professional measurement the devices must be adjusted to the sensor which is possible with the expert setup (give us a call, e.g. email). For personal use the defaults should be sufficient (please give us feedback if you have problems). - Currrently the calibration of the latest iPhones .. iPhone X is not yet included - soon an update follows. Its using default settings instead. You can load older versions of the App if the phone is not supported in the newest version (due to App Store Limits) via iTunes.

You also need to do a noise calibration which is automatically requested after the first start. After this, the background noise must be set. This is done after the calibration is finished, with a 4 or 10 minute measurement. You will be given instructions according to the results. Sometimes you need to repeat the noise calibration if the values get too high.


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Here are some measurement results with the different devices in the range from 2 uGy/h till 10 Sv/h. You don’nt need to enter any values in the App, as the different curves are already stored in the App. If a new device comes out, or your device is not in the table, you might find a value id:0 at the first page, then please write us an email so we can look after your specific device and tell a correction factor (scale in the setup menu as soon as possible). Except for the iPhone 3GS we use the frontcam as its more sensitive then the backcam. Proper light shielding is important, please also look into the FORUM for hints and discussions. Update for the APP (1.1) is in work, it will include the possibilty to switch between front- and backcam, therefore we did a new measurement of all devices for front- and backcams. Attention with version 1.0 the frontcam of iPhone 5 is used with wrong values !!! The frontcam is very insensitive, so you might need to use a scale of less 1 to get real values with the old version.


		iPad 2 with a 612 minutes background radiation measurement. Sometimes larger traces are visible from secondary electrons, when particles (for example gamma rays) hit the camera sensor. We do amplify these hits and display them in the cloud chamber modus. The fade out time can be adjusted in the setup menu. The front camera of the iPad 2 is very sensitive even on lower radiation values. A very rare long trace is visible here, its pointing to the window of the room (it was at a 80 degree holder for long time measurement - it could be a cosmic Myon / Neutron converted hit with high energy released)

iPhone 4S showing gamma radiation from a CO60 source (1.1 & 1.3 MeV). Also some traces from secondary electrons are visible. They always give typical images. At the Buchler device we have CS137 and CO60 sources for testing and calibration.

iPhone 4S with a measurement running and the initial assignment curve shown (automatically determined).

	Statistic view. The measurement is CS137 in the Buchler device at the Helmholtz Research Center up to 1 Gy/h (air carma). We used this for calibration of our devices. A mean value is used as default value for the different iOS units, as iPhone 3GS, iPhone 4, iPhone 4S, iPod 2 and iPad 2. Some variation on the individual phones are possible for each model of course. With a scale factor it’s possible to calibrate phones individually if necessary for precise professional measurements.

Showing a iPad2 with a measurement at the Helmholtz Research Center Munich after the automatic calibration with the defaults and in comparison the value on a Geiger Counter (5% precision according to the manufacturer). Radiation is with a CS 137 Source at 1 mGy/h (defined by source and distance around 4m distance of the source). Our measurements shows the same doserate value as the Geiger Counter (assumed 1Sv/h = 1 Gy/h in this case). The statistic display shows the other measurements we made before with 100 µGy/h etc (left is the latest - show mean values on a 10 minute interval).


	(C) 2018 MultiMediaStudio Dipl. Ing. Rolf-Dieter Klein