Testing the apple radiometer

Measurement of the background radiation under the Copper Rider

I decided to check how DO-RA works in traveling.

DO-RA is a compact instrument for measuring radiation. Stuck into the audio input of the iPhone and the phone starts working as a household dosimeter. Of course, beautiful screens, high-quality fonts and a lot of additional information and iOS services become available to you.

I like the opportunity to photograph landscapes and objects and send the resulting pictures to my friends with the current level of background radiation. I love fixed protoplasm.
Of course, the story of the journey is illustrated with photographs from these letters.
')

Instruments

The iron I used on the way:
• iPhone
• iPhone 4S
• DORA prototype 002 (in the photo on the right)
• DORA industrial design 003 (left)



Programs downloaded to the phone:
• DORA 2.20 from the appStore (in the photo in the center is a screenshot of the monitoring of Sarov)

How to measure radiation

At once I will say that the DORA device is indicative, soldered on the basis of the SBM-21, catches only gamma rays. A typical background radiation level corresponds to 1-2 caught gamma quanta per minute. Translated into the language of physicists, this is about 0.05 micro-sievert per hour. For those who do not like sievert, you can go to x-rays, multiplying the number of sieverts by about 100. By the way, Roentgen was German and Sievert was a Swede.
And the SBM-21 device was made in Mordovia.

It generates up to 6 parasitic pulses per minute, so it’s pointless to talk about any accuracy. With a low background radiation level, of course. High values ​​are caught very well, for example, a compass from a German submarine gives 1000 pulses per minute, which corresponds to 60 micro sievert per hour. To get these numbers, you must put the phone with DORA in centimeter proximity to the compass. At a distance of an outstretched hand from a fascist device, increased radiation is not observed. 10 pulses per minute. For comparison, the granite monument under the Bronze Horseman showed 12-14 pulses. But more on that below.

DORA hardware

A little about the hardware. DORA is powered by the iPhone and additionally consumes 0.03% of the phone's battery power. To discharge the iPhone's battery with our device, we need 3,000 hours of continuous DORA operation.
Every 4 seconds, it sends a sinusoidal signal, which stores 60 bytes of information about the serial number, software version and protocol type, the level of accumulated radiation, the accumulation time. Bits are encoded by frequency shift keying. The wave of the sine wave for the period is 0 (zero). A pair of waves is 1 (unit). All this has long been standard. Bits are added bytes - bytes in strings and numbers.
With a frequency of 44100 (iOS specification), DORA manages to transmit all information in 1.5 seconds. Then, another 2 seconds are needed to charge the capacitors, they need to gain strength to send the next 60 bytes. Based on these figures, you can calculate the number of audio samples per 1 sine wave period and make your own protocol.

May Holidays 2012

So, I hit the road.
On sleepers and rails.



Started from Sarov, where they make atomic bombs. The radiation level in the former Arzamas-16 is normal.
Corporate train 58 NN-SPb showed no danger. Coupe, linen, conductor, tea, bio-outhouse - everything is normal, except for the ticket price. 5400 rubles - I flew to America cheaper. Our country is rich.

Peter delighted with cold and 6 gamma pulses per minute. Fonit is a great city. Not by chance, half of St. Petersburg residents walk without hair.

In the photo a typical aborigine

After the Volga (+25), I looked in slaps and shorts ridiculous on the Leningrad (+4) platform. Half of them were dressed in winter boots, and one aunt (pretty) was wrapped in a fur coat. Petersburgers ironically squinted at my uncovered iPhone with the DORA fastened. It is not customary to throw Ponte. To explain to them that I was not a dude, but the dosimetrist on vacation was useless.

Center of Petersburg

Having started the DO-RU, we went with the aborigine to plow the historic center of North Palmyra. On Habré there was an article about the IT-restaurant opening here. The restaurant, alas, was not found.

The Bronze Horseman, Arrow, Leningrad Eskimo

But the Admiralty, Isaac, the Bronze Horseman, the Synod, embankments, the Hermitage, the Palace Bridge, the Eskimo, the Stock Exchange, the Rostral Columns, the Kronverk, the newlyweds, the Peter and Paul Fortress, the beach, nudists were discovered and tested for radiation. The device dispelled the legend that granite embankments are radiation dangerous. And only the Bronze Horseman did not disappoint, gave a small burst of gamma particles.

Pine Forest and Kronstadt

The next day, the Fellowship of the Ring moved along the Ring Road to Sosnovy Bor. There is a nuclear power plant in Sosnovy Bor, and it was curious to measure the level of radiation in this pretty city. At the same time drive through the tunnel under the Gulf of Finland, which closed the ring around Leningrad. Thank God, in contrast to 1941-43, the ring was not an enemy, but an automobile one.

Koporskaya fortress, nuclear power plant in Sosnovy Bor, Andersen Grad, Kronstadt

Sosnovy Bor is a secure city and just can’t get into it. I had to make a circle through the ancient Koporsky fortress (1297). Neither the old fortress, nor the new nuclear power plant, nor the renovated Naval Cathedral in Kronstadt (measured on the way back), did not detect increased gamma radiation. On the outskirts of Bor do not ask for documents.

In the days of Victory, it was impossible not to call in Oranienbaumansky Fort, where on the railway platform there has been a sea howitzer that sank German ships on the railway platform.

The number of stars on the trunk should correspond to the number of flooded ships.

Other places in North Palmyra

In the Leningrad metro gamma radiation almost was not. Earth's bowels keep us. In the Ice Palace, where we ran hockey with the Mozhaisky Institute, 5 pulses per minute were caught. In the computer shop - 4 impulses. In the LenSoviet theater, the phone had to be turned off. Measure Anna Kovalchuk failed.

Metro, Ice Palace

During a three-hour walk through Peter with the iPhone turned on in monitoring mode, the maximum background level is 0.60 μSv / hour. And on average 0.1 - 0.3. The city can sleep peacefully.

Impressions

I will say as a user. After 3 hours of continuous operation, the iPhone 4S died. It is sad. The reason is 100% bright screen and constantly on 3G mode. The old iPhone monitored the whole day and was discharged less than half. It is joyful.
I made my way back from Petersburg in a car I bought for the money from the author’s iPhone game. On the rear window of the car, I pasted a grateful inscription printed in the magnificent St. Petersburg printing center.

#include <ios.h> 

On the way, the cities of Vyshny Volochek, Tver, Klin, Moscow, Serpukhov, Tula, Ryazan, Shatsk, Sasovo were checked.
All right, no anomalies detected.

About crap

On the sixth day of operation, the branded beautiful DORA broke in the shape of a corkscrew. Cracked badly glued plastic case.

You can see the contents of iron

In addition, a significant inconvenience of this form factor was found. Cocktail closes the phone off button. It infuriates. You have to shoot DORA, turn off the iPhone, then put the DORA on again. In short, uncomfortable. For the sake of fairness, I will add that upon return the building was re-glued and did not fall apart anymore.
But I liked the device in the form of a flexible antenna much more. Among other things, it is suitable for all types of iOS devices. Unfortunately, audio plugs for iPhone, Android devices, WinPhone7 and Symbian Nokia are different.

About the program

The program sometimes had to restart. In 25% of cases of getting out of sleep or DORA, she stopped recognizing the signal and signaled that the digital packet was missed.
The interface is clear, localization for 3 three languages ​​- Russian, English, Japanese. All travel data is stored on the server and any user of the program can track the current level of radiation according to Roshydromet and other DORA users.
In addition, I liked the music. Lying in his pocket, DoraFon quietly clicked every 4 seconds with a green background level and twice as often when approaching the orange zone. The red zone corresponds to the howling of a siren - I have never heard it in 10 May days.

What's next?

And then instead of the SBM-21, a silicon sensor is being prepared, which will most likely be released in the next form factor (on the left in the photo). I hope during the summer all the research and design will be completed.

Thank you for your attention, purchased validol.