Bob's Rock Shop Product Review
The $8 BIRI Russian Radiation Detector

While I was browsing the 1996 Tucson Show I happened to come across these rather remarkable Russian-made radiation detectors with rechargeable batteries and line powered chargers which were being sold for only 8 bucks! I was overwhelmed with the absolute coolness of these little gizmos, especially after conjecturing and musing over them a bit as cultural artifacts.

Although I haven't (yet) been involved in collecting radioactive minerals, this detector's obvious potential utility to rockhounds as a very cheap and very packable Geiger counter was something I just had to check out. These detectors were purported to be functional and one was demonstrated to me at the Show by holding some "uranium ore" up to it, which caused the LED to flash. Since I figured they might have an even greater coolness factor if they don't work or only work intermittently, I just couldn't resist doing a little independent testing and present the results in Bob's Rock Shop's very first product evaluation report.

They're not what you'd call export models and don't have English instructions. In fact, if there ever were instructions in any language included, they had become separated by the time I acquired mine. There is some Russian writing on the box, and rockhound Karl Vermillion has supplied the following translation (done by a Russian reading co-worker) and the following anecdotal information:

    The brand name of the instrument is translated as BIRI, which is the 4 letters found on the carton front. Curiously the carton calls it a BIRI-1 and on the detector back it calls itself a BIRI-2. The letters BIRI are the first letters of the first 4 words on the carton side. These 4 words literally translate to "keychain detector for radioactive radiation". I ask what other kind of radiation was there. His reply was that in Russian light is always called radiation. Radioactive radiation in Russian would be better translated as ionizing radiation in English.

    The carton side says something like "Keychain Detector for Ionizing Radiation will give you plenty of warning about dangerous radiation".

    The carton back is funny. It says that the device was made in the Ukraine, but the box is not written in Ukrainian. The top 3 groups of lines are the equivalent of our mil spec numbers, that have no real meaning. The fourth group says that it was made in the "Thermoplastic Automat" (apparently a huge factory complex, formerly entirely military) and the last line says it was made in the "Electromachine" division.

    The only real information appears on the back of the detector. The chart says that under 12 flashes per minute is "safe". 24 to 60 flashes per minute equals 120 to 300 micro Roentgens per hour. Continuous light means more than 3000 micro Roentgens per hour (3 milli Roentgens per hour). For comparison, normal background is about 10 micro Roentgens per hour, and total lethal dose is about 300 Roentgens in a 24 hour period. New York to LA flights and chest X-rays are both several Roentgens, I believe. A Roentgen is a measure of the number of particles zippin through your body weighted by the damage each of them cause. A measure of how fast you're gonna die, basically.

    Alex was in Byelorussia when the Chernobyl accident happened several hundred miles away, and he said that the radiation count was about 10000 microRoentgens per hour at his school. His opinion is that these devices were made after the breakup and sold to people near the fallout zones. He told me that his parents routinely check any fresh produce they buy for radiation with the fancy meter he bought.

    The detector will almost assuredly not pick up alpha particles, certainly will detect gamma rays, but whether or not it'll detect beta depends on the thickness of the window on the front of the detector. Salt substitute (good old KCl) might be radioactive enough to trip it, and potassium-40's mode of decay is beta and electron capture. So if you're interested, go by a bottle of salt substitute that contains KCl, KBr, etc., and see what happens. As an aside, I was once told that potassium salts were set as the legal limit for what was considered to be radioactive in this country, but that is not confirmed.

I have determined that my detector does indeed work. My experiments so far have only been qualitative in nature. After learning that many smoke detectors use a radioactive element, I was able to do some quick testing and I checked out the one in my apartment. No doubt about it, it's "hot", and the detector was clearly affected by it! The LED occasionally flashes at random when the detector is on, which I assume to be due to natural background hits. When the BIRI is brought near the smoke detector, the LED flashes much more frequently. A label on the smoke detector states that it "Contains Radioactive Material Americium 241 1.0 Microcurie."

You may have noticed that the chargers aren't going to plug into 120V/60Hz US-style receptacles without a few mods. I very crudely adapted mine for my initial tests by simply wrapping the stripped ends of a salvaged lamp cord around the charger plug prongs. Unless you have degrees in electronics and an FCC General Radiotelephone License with Radar Endorsement like I do, I would suggest at least using a little plastic electrical tape to insulate such a lash up. Me, I'm just not living right unless I get shocked at least once a day.

Electronically, the charger is a very simple half-wave rectifier which is current limited by a high impedance series resistor. This circuit sits right on the line, there is no transformer. It supplies about 2 milliamps of charging current to the cells when powered by a 120V/60Hz line. A six hour charge brought the cells up to a serviceable voltage level. You must be careful to place the nicad button cells into their receptacles on the charger with the proper orientation regarding their polarity. This charger is as dumb as they get and will function very well as a nicad button cell destroyer if you place them in backwards! Screw this up and you're going to need some new batteries.

Fortunately, there are injection molded polarity marks on the case. Unfortunately, the polarity marks don't mean "orient this cell so that the indicated terminal faces out and matches this mark". It means "place the indicated terminal of this cell facing down against the cell contact". This leaves the opposite polarity terminal of the cell facing outwards from the polarity indicated by the molded mark on the case.

Besides reverse charging the batteries and destroying them, it's also possible you could get that part right and then install them backwards in the detector. One would hope the electronics in the detector were engineered to survive this mistake, but I wasn't willing to risk mine to find out. I guess when you're using a Russian radiation detector, you've got to install the batteries in Russian... I was forewarned concerning this confusing reversal of convention when I purchased the detector at the Show. I haven't seen too many Russian manufactured button cell powered devices, but I can see where my confusion could be due to a cultural convention thing. Then again, maybe I'm just confused.

I've yet to take it field prospecting for radioactive minerals, but now that I know my BIRI actually works and can detect what (I assume) is a pretty low level of radiation, I think it's a pretty neat little gizmotron. Now all I need to do is study up on radioactivity, radioactive minerals and start my own collection of "hot" rocks! I may present some future material on radioactive minerals and collecting as I learn more about and explore that somewhat exotic rockhounding niche.

Further BIRI Notes and Tips

The source I purchased my BIRI from is now exhausted and unfortunately the 'street price' on BIRIs has apparently increased somewhat. I last saw them offered at the '98 Tucson Show for $25 or so and up.

If you're lucky enough to get a BIRI and then you have problems with it, I wouldn't exactly hold my breath over factory support or service if I were you! However, for what it's worth, BIRI enthusiast John Wasser,, sends this info from the manual which accompanied his:

The instruction manual that came with my BIRI radiation detector includes the address of the manufacturer in the Ukraine. It is written in Cyrilic letters but here is how it translates:

Country: Ukraine
Postal code and City: 282001 Ternopol
Street address: Post Office Box 61
Adressee: Ternopol Experimental Production Facility for Radio-Electronics and Technology
John has published scans at his web site of the (Russian) instructions which accompanied his BIRI. John also sends this battery tip:
Thanks for the article on the "BIRI" keychain geiger counter. I learned a few things that I did not know about mine. I saw them at a flea-market at MIT in Cambridge, Mass. They came in two colors: white and (if I recall) dark green. I got a white one. They were selling for $20 with the original Russian instructions but no batteries or charger.

Just yesterday I found that the DURACELL PX625A (replaces PX13B and PX625B) fits perfectly in the little plastic rings in the battery compartment. They even fit only the correct way (the positive side is smaller in diameter than the negative side). Before that I used inexpensive zinc-air cells that were a very sloppy fit in the battery compartment but worked fine.
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Bob Keller