Apple Radiometer Test

Measurement of radiation background under the Bronze Horseman

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

DO-RA is a compact instrument for measuring radiation. It sticks into the audio input of the iPhone and the phone starts to work like a household dosimeter. Of course, beautiful screens, high-quality fonts and a bunch of additional information and iOS services are available to you.

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

Instruments

The hardware I used on the way:
• iPhone
• iPhone 4S
• DORA prototype 002 (pictured on the right)
• DORA industrial prototype 003 (pictured on the left)



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

How to measure radiation

I must say right away that the DORA device is indicative, soldered based on SBM-21, it catches exclusively gamma quanta. The usual level of background radiation corresponds to 1-2 captured gamma rays per minute. Translated into the language of physicists, this is approximately 0.05 micro-sievert per hour. For those who do not like sievert, you can go to x-rays, multiplying the number of sievert by about 100. By the way, X-ray was German, and Sievert was Swede.
And the SBM-21 device is made in Mordovia.

It generates up to 6 spurious impulses per minute, so talking about any accuracy is pointless. With a low level of radiation background, 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 need to put the phone with DORA in a centimeter proximity to the compass. At an arm's length from the fascist device, increased radiation is not observed. 10 pulses per minute. For comparison, a granite monument under the Bronze Horseman showed 12-14 pulses. But more about that below.

Hardware DORA

A little bit about the hardware. DORA is powered by the iPhone and additionally consumes 0.03% of the phone’s battery power. In order to drain the iPhone’s battery, our device needs 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. A sine wave for a period is 0 (zero). A pair of waves is 1 (unit). All this has long been standard. Bits are added bytes - bytes into strings and numbers.
At a frequency of 44100 (iOS specification), DORA manages to transmit all the 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 numbers, 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 the sleepers and rails.



Started from Sarov, where they make atomic bombs. Former Arzamas-16 radiation levels are normal.
Named train 58 NN-SPb did not show any dangers. Coupe, linen, conductor, tea, bio-toilet - everything is fine, except for the ticket price. 5400 rubles - I flew to America cheaper. We have a rich country.

Peter pleased with the cold and 6 gamma pulses per minute. Fonit is a great city. It is no coincidence that half of the residents of St. Petersburg walk without hair.

The photo shows a typical native

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

Center of Petersburg

Launching DO-RU, the native and I went to plow the historical 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 popsicle

But the Admiralty, Isaac, the Bronze Horseman, the Synod, embankments, the Hermitage, the Palace Bridge, the popsicle, the Exchange, the Rostral Columns, 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 hazardous. And only the Bronze Horseman didn’t let us down, gave a small burst of gamma particles.

Sosnovy Bor and Kronstadt

The next day, the Brotherhood of the Ring moved along the Ring Road to Sosnovy Bor. There is a nuclear power plant in Sosnovy Bor, and it was interesting 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, unlike 1941-43, the ring was not enemy, but automobile.

Koporskaya fortress, NPP in Sosnovy Bor, AndersenGrad, Kronstadt

Sosnovy Bor is a regime city and just can’t get into it. I had to make a circle through the ancient Koporye fortress (1297). Neither the old fortress, nor the new nuclear power plant, nor the restored Naval Cathedral in Kronstadt (measured on the way back) found increased gamma radiation. At the exit from Bor, they do not ask for documents.

In the days of Victory, it was impossible not to drop into Oranienbaumansky Fort, where, from the time of the blockade, a sea howitzer drowning German ships has been standing on a railway platform.

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

Other places of North Palmyra

In the Leningrad metro there was practically no gamma radiation. The bowels of the earth keep us. In the Ice Palace, where we ran hockey with the Mozhaisk Institute, 5 pulses per minute were caught. In a computer hardware store - 4 pulses. In the LenSoviet theater, the phone had to be turned off. It was not possible to measure Anna Kovalchuk.

Metro, Ice Palace

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

Impressions

I’ll say as a user. After 3 hours of continuous use, the iPhone 4S died. It is sad. The reason for this is a 100% bright screen and always-on 3G mode. The old iPhone monitored all day and discharged less than half. It is joyful.
I made the return trip from St. Petersburg in a car that I bought for the money earned 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  

On the way, the cities of Vyshny Volochek, Tver, Klin, Moscow, Serpukhov, Tula, Ryazan, Shatsk, Sasovo were checked.
Everything is in order, no anomalies were found.

About the fly hood

On the sixth day of operation, the branded beautiful DORA in the form of a fly-hood broke. The poorly glued plastic case cracked.

You can see the contents of iron

In addition, a significant inconvenience of such a form factor was found. The hood closes the phone's mute button. It infuriates. You have to remove DORA, turn off the iPhone, then put on DORA again. In short, uncomfortable. In fairness, I’ll add that upon returning the case 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, the audio plugs for iPhone, Android devices, WinPhone7 and Nokia Symbian's are different.

About the program

The program sometimes had to be restarted. In 25% of cases of waking up from sleep or DORA, it stopped recognizing the signal and signaled that the digital packet was missed.
The interface is clear, localization into 3 three languages ​​- Russian, English, Japanese. All travel data is stored on the server and any user of the program can track the current radiation level according to the data of Roshydromet and other DORA users.
In addition, I liked the music. Lying in his pocket, DoraFon quietly clicked once 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 SBM-21, a silicon sensor is prepared, which, most likely, will be released in the next form factor (on the left in the photo). I hope that during the summer all research and design will be completed.

Thank you for your purchase Validol.