Detecting Radiation For Fun And Profit

It used to be that every well-stocked doomsday bunker had a Geiger counter. These days, you don’t have to have a big tube-based meter. You can inexpensively get a compact digital instrument to handle your radiation detection needs. [DiodeGoneWild] reviews and tears down such a unit from FNIRSI. The case looks like several other similar instruments we’ve seen lately, so presumably, someone is mass-producing these handheld meter cases. You can see the video, below. The meter reads the absolute radioactivity and can also measure cumulative exposure.

After measuring a few common radioactive items, we get to the teardown. Inside, of course, is an ordinary tube. A few screws reveal a typical rechargeable battery, a fairly simple PCB with a microcontroller and battery backup for the real-time clock. A lot of the board is involved in multiplying voltage up to the several hundred volts required for the Geiger tube.

The other side of the PCB has only buttons, a vibration motor, and, of course, the LCD. We don’t know how you might test the relative accuracy other than comparing it to a known-good meter. The bare tube was, of course, more sensitive without the plastic cover, but that could be calibrated out, too.

A Geiger counter doesn’t have to have a lot of parts. Either way, a surprising number of things will set them off.

19 thoughts on “Detecting Radiation For Fun And Profit

      1. I bought a slightly used russian one from an Ukrainian atomic plant. It was wirking, but radioactive in it self, so not so accurate. Now 30 years later, it kind of mostly got away but still elevated.

    1. Ummm… The vast majority of fallout is low levels. Also I seriously doubt you can see the components in the pictures well enough to tell if they are rad hardened or not.

      Rad hard components and shielding are only required for intense fields for extended times.

      Note: I have had my cellphone in Rad and contamination areas without issue.

    2. Having actually tested ordinary consumer devices for radiation sensitivity, I can tell you your concerns are completely unwarranted. No rad-hardening is required, because ordinary consumer-grade stuff keeps functioning just fine after many hundreds of times human-lethal dose.

    3. Yeah, because people buy these in case of a nuclear war…

      But seriously, if there is enough radiation to destroy your cheap meter, you have far more important concerns to worry about.

    4. What you are saying reminds me of the “Weather Rock” a rock hung on a string used to tell the weather.

      “If the rock is wet, it’s raining.
      If the rock is swinging, the wind is blowing.
      If the rock casts a shadow, the sun is shining.
      If the rock does not cast a shadow and is not wet, the sky is cloudy.
      If the rock is difficult to see, it is foggy.
      If the rock is white, it is snowing.”

      If your Geiger counter is malfunctioning due to high radiation, you’re already utterly screwed.

  1. They should put geiger counters in every cellphone so they know how to steer the Population to stay away from those areas, how to appropriate responses and distribute resources, etc. The cellphones could constantly report radiation levels and their corresponding locations. Authorities could potentially almost immediately block a highway that leads to a nuclear power plant that just had a meltdown, or an entire street from an apartment that emits dangerous levels of radiation from an employee that lives in the apartment that was exposed to high levels of radiation. We’d know of leaks at x Ray labs by readings reported by neighboring Patients’ cellphones automatically reporting dangerous levels much like it constantly updates locations with GPS chips and even apps like Google photos, maps, etc. I’d like to pitch it to cellphone companies and large government organizations, police forces, etc. I think that if one of you techies can invent a geiger counter, small, yet efficient enough to work from inside a common smartphone, that is “cheap” enough to manufacture that it would be economically viable for a nuclear reactor company like a “Chernobyl Plant” to pay a “little extra” for their company’s employees’ cellphones to come with this feature to ensure they aren’t bringing their work home with them and radiating their homes and families, neighbors, supermarkets, etc. Plus, you’d probably get lucky at a checkpoint or something as an officer that walks past a vehicle stopped at the Mexican border suddenly hears his cellphone start beeping and then they’d know to stop that car, or pull if over if they didn’t catch it right away. Anyway, I like the idea. If one of you guys want to get the mechanism invented and patented, or something, we could pitch it to big bucks companies like government agencies, LG, etc.

    1. There already exist bluetooth connected sensors. The small sensors are expensive, as much as my whole (cheap) smartphone. The cheap ones are large, as large as my slightly older smartphone.
      On you can find the map that contains a lot of data from bluetooth connected sensors. It’s graphically represented as colored tracks.

  2. Remember that without proper calibration, these are count meters and not dosimeters. A GM tube alone does not a dosimeter make, in the same way a random LDR does not a Lux meter make.

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