Biri-2 Geiger Counter, Tested, Audio Signal Uses SBM-10 Geiger Tube

Description

Biri-2 Key Chain Geiger Counter. Refurbished  Tested, Guaranteed
The Biri-2 is a unique electronic device. It was created by the following the famous 1986 Chernobyl Nuclear disaster for use by Soviet citizens to check for radiation contamination on foods and in water. Because the radiation had contaminated thousands of square miles of farm land, it endangered the whole food chain and water supply of the locals. To combat this, and give the people some convenient “tool” they could use to test for dangerous levels of radiation in their food and water supplies, the Key Chain “Dosimeter” (Geiger counter) was invented. It was made as a key chain, to be held unseen, cupped in the palm of your hand. With the switch turned on, people could discretely check meat and vegetables at the market or food stall for danger.
Limited Availability
: The Biri-series Geiger Counters, which had only a very limited production back in the 1980s, are now becoming rare.
Made in quantities of tens of thousands, these were handed out to a great many families. Now, they are extremely hard to find and rarely found listed on ebay.
Currently, the only sources for these are a few Eastern European companies. But even their supplies are diminished, and it is only a matter of time before those stocks will become depleted. The few units we have for sale were purchased new over 12 years ago from stocks that had been in storage since the 1980s and were completely new, still in their original cardboard containers when we bought them. These have never been used. The only signs of aging are cosmetic, with occasional minor scratches on the outside, and from when we open the case to attempt repair of the LED.
Quality
: Like the famous miniaturized spy recorders and cameras made by the Soviets during the Cold War, the Biri-2 is equally a masterpiece of Soviet engineering and miniaturization, measuring only 2.2 ”x 1.4” x 0.6 ”(70mm x 40mm x18mm). Generates a jolting 400DC volts for the GM tube, and has a very low current drain, allowing one set of batteries to last more than 100 working hours. It uses  an audio buzzer when gamma, beta, or X-Rays are detected. The red LED is non-functional in this unit.
Advanced Engineering
: The circuit is laid out on an older style printed circuit board and used 3v for power, with tiny transistors, diodes, resistors, capacitors, and a miniature 1” long geiger tube. It is extremely sensitive, using an SBM-10 or SBM-21 GM tube, sold separately on eBay for upwards of .99 each! These tubes were made at the same factory that produced the famous SBM-20 tubes. They are responsive to general background and to elevated levels of Beta and Gamma radiation (beta and gamma), the background producing normal ‘ticks’ in a steady stream (i.e., once every 15-60 seconds), with a periodic louder distinct buzzer noise when hit by a random Gamma particle a few times a minute. However, when near a source of heavy radioactivity, the buzzer emits constant warning beeps.  An SBM-10 or SBM-21 Geiger tube is included.
On the back of the device is a color-coded scale giving you the relative danger level:
Green
- 12 beeps per minute (bpm) is safe, representing normal background radiation;
Yellow
- 12 10 24 bpm indicates caution;
Red
- 24 to 60 bpm indicates a potential hazard; and higher than 60 bpm is downright dangerous.
These originally came with rechargeable button batteries (2 x 1.5vdc) and a battery re-charger (220vac). However, since the Soviet batteries are not replaceable, and the charger worked only with European-style electrical outlets at 220v, we opted to get rid of these and substitute non-rechargeable PX625/LR9 button batteries. These batteries work great and are included with your purchase.
Included:
1 x Biri-2 Geiger Counter (Value = .00, with LED functioning))
1 Set of Two New PX625/LR9 Batteries  (Value = .50)
1 New SBM-10 or SBM-21 Geiger Mueller Tube (Value = $ 29.95)
If purchased separately, the total value is arounf .00
Any questions, just let me know, thanks. Good luck on your bidding!