Geiger Counter Nuclear Radiation Monitor Detector For Windows and Macintosh

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Black Cat Systems offers a wide range of geiger counter based nuclear radiation detectors. In addition to our stock items, we offer customized solutions for your radiation sensor needs.

Our radiation detectors are being used worldwide to measure possible radiation from the Fukushima nuclear accident. We have dozens of detectors in Japan alone, with real time readings displayed on this map, as well as many in use here in the United States.

The GM-10 and GM-45 are sensitive and affordable ionizing radiation detectors, also called geiger counters, with prices starting at $249 for the GM-10 and $349 for the GM-45. These highly sensitive geiger counters are capable of detecting extremely small amounts of radiation. Visit our Detector Comparison Page for details about all of our geiger counter based radiation detectors.

A geiger counter lets you check the environment and items for radioactivity. You can use to check for the presence of radon on your house or basement, or even use it to go prospecting for uranium or other radioactive minerals. The GM-10 and other members of the geiger counter family can detect radioisotopes such as Polonium 210 which was used to poison Alexander Litvinenko.

A geiger counter works by detecting the ionization produced by a radioactive particle. Each time a particle of radiation is detected, the counter records this event. The number of events recorded over a period of time indicates the amount of radiation present. Often this is done over one minute intervals, resulting in the familiar "counts per minute" or CPM. The higher the CPM, the higher the radiation levels. You can read a more in depth description of how geiger counters work.

Radioactivity is the emission of energy from the nucleus of certain nuclides or elements. Some naturally occuring radioactive elements include uranium and thorium and radon. A small amount of naturally occuring potassium is even radioactive.

There are three types of radioactive emissions:

  • Alpha - the least penetrating form of radiation, can be stopped with a piece of paper or a few inches of air. Alpha rays are the nucleus of a helium atom, and are produced by certain radiactive materials such as thorium and uranium.
  • Beta rays are more penetrating than alpha rays, and can be stopped by a few millimeters of aluminum or other metals. They are very fast moving electrons.
  • Gamma rays are the most penetrating form of radiation. Depending on their energy, they can travel through up to several inches of steel, and hundreds of feet of air. They are usually produced in conjunction with either alpha or beta rays.

The difference between the GM-10 and GM-45 (and our other models) is the size of the radiation sensor. The sensor in the GM-45 geiger counter has 24 times the surface area of that in the GM-10 making it more sensitive, especially for alpha and beta radiation sources. That means that it can detect weaker levels of radiation.

The typical background levels detected with the GM-10 are around 10 CPM. This can be substantially higher in the basements of homes with high radon levels, for example. A GM-10 on an airplane flight recorded a level of over 400 CPM, due to the large amount of cosmic radiation always present at high altitudes.

The GM-10 and GM-45 geiger counters connect to almost any personal computer (either a PC running Windows or the Macintosh) through a simple serial interface. The powerful software included with them allows you to measure, record, and display radiation readings over any time period.

The GM-10 and GM-45 geiger counters are self powered off the computer's serial port, no batteries or external power supply is required. This makes them ideal for use in the field, or other locations. Just connect to a laptop, and you're ready to go!

A USB version of the GM-10 is available as well. Now you can use your GM-10 with a laptop or other computer with only a USB port available. A USB version of the GM-45, with the larger detector window, is also available.

The GM-10 and GM-45 geiger counter may also be used as radiation sensors and connected to other equipment, we'll be happy to provide connection and operation information to those interested, as well as OEMs. Users have sucessfully used the GM-10 with various microcontrollers. Interfacing details are available. Please feel free to contact us with any questions you may have.

The GM-10 and GM-45 detect alpha, beta, and gamma and x-ray radiation. Full specifications are available.

You can view the current readings, or display graphs showing the change in radiation levels over time.

You can also have the software automatically upload the graphs to your web site, so you can put your unit online! Take a look at our Online GM-10

The GM-10 and GM-45 geiger counter are perfect for educational and industrial uses, the hobbyist or scientific experimenter, as well as anyone interested in determining the radiation levels around them!

There are many sources of radiation found throughout the home, workplace, and natural enviroment. The GM-10 and GM-45 will let you know what the radiation levels are in your enviroment!

Many common products, including some foods, are radioactive. We have details on our Radioactive Products and Other Sources Of Radiation page You can use the GM-10 and GM-45 to test unknown objects and packages, before opening them, to verify that there are no radioactive materials inside. You can also monitor the background radiation levels in your home or office, and quickly detect any increase in readings due to a nearby radiation accident, spill, or other incident.

We also have a basic tutorial on the different types of radiation found in the enviroment, including radioactive dust found in almost every home in the US, at our Amateur Radiation Detection and Experimentation Page

The GM-10 and GM-45 require a Windows or Macintosh computer with an available RS-232 serial port (USB to serial adapters on a laptop, Macintosh iMac, iBook, Cube, etc work fine, not included, see our FAQ).

Pictured above is the GM-10 geiger counter (to the right) connected to a laptop (not included). One of our vaseline glass beads is in front of the GM-10.

Pictured above is the GM-10 geiger counter (to the right) connected to an iBook (not included). A small uranium ore sample is in front of the GM-10.

Vaseline Glass Test Source

Need a safe way to test out your geiger counter? Try our vaseline glass bead. Vaseline glass is a type of glass with a small amount of uranium oxide added, which makes it glow under ultraviolet light (also called depression glass). This also makes it slightly radioactive. With the GM-10, we get about 200 CPM with the bead directly in front of the detector window, or about 0.2 mR/hr.

The bead is available for just $9.99, and may be ordered online or you can order by mail We're having a special right now, you can get 5 beads for just $39.99!

This item is safe to handle, and legal to own.

Thinking of buying a surplus CDV-700 or 715 detector? Be sure to read our report first.