Gamma-Scout® is the right product for you if you wish to ensure your environment is free from significant radioactive contamination. One of the major benefits of the Gamma-Scout® is that it is highly sensitive to extremely low levels of radiation. For instance, it can even measure the radioactivity in granite countertops.

For general radiation measurement applications, we have 4 basic customer groups:

The first group comprises safety and rescue organizations, such as police and fire departments, emergency response organizations, private security firms, hazardous material disposal and metal recycling companies. This group also includes customers who are simply interested in checking a package, suitcase, vehicle, loose material, or any object they believe could be contaminated.

The second customer group is private individuals concerned about personal safety, or people wishing to own a reliable device for measuring environmental contamination – at home or while travelling (in the event of an environmental incident or terrorist attack).

The third customer group consists of educators or hobbyists who want to test various materials
or demonstrate principles of radioactivity.

The fourth type of customer is hospitals, labs and any organizations that handle radioactive materials or generate radioactive emissions. Many of our customers work in the medical field (such as radiologists or dentists). We even sell Gamma-Scout® to air-freight pilots who check their cargo before flying “just in case”.

The bottom line is that if you, your company or your organization believe you may encounter radioactivity (even if that possibility is remote), and you want to protect yourself against this potential danger, information and knowledge is a critical factor in your protection. In which case, you should own a Gamma-Scout®.

Mentioning nuclear incidents and terrorist attacks is not intended to stir up fear or anxiety; it is merely an unfortunate reflection of today’s reality (e.g. Fukushima). The potential risk cannot be ignored. Therefore, although Gamma-Scout® was originally developed before 9/11, it has been optimized for use in the event of nuclear incidents or terror attacks. In such situations (unless you’re at ground zero), your exposure to radiation will probably be at relatively low, but may gradually rise. In fact, there may be no initial signs in your immediate environment.

Gamma-Scout® detects changes in ambient radiation levels with a precision of less than one percent deviation. Drifting radioactive material can settle on and inside your house, contaminating your food or water. With Gamma-Scout®, you don’t have to check radiation levels every day. The built-in buffer memory allows you to download accumulated measurement data onto your PC to display even minor changes in radiation levels over many years. And you have the option to activate an audio alert should radiation reach a user-programmable level.

Many people are unaware of how much radiation is all around them and how much exposure can harm or, in the worst-case scenario, even kill them.

There are many sources, some of which can go undetected for years. Things like nuclear waste, leaks from nuclear power stations or waste storage facilities are ongoing risk factors. Plus, we are now faced with new threats in the form of terrorist attacks.

Also worth mentioning in this context are emerging terrorist countries and new nuclear powers.

The Gamma-Scout® Geiger counter displays radiation exposure rate µSv/h (microsievert/hour). The sievert is an internationally recognized unit that indicates the biological effect of radiation – the so-called equivalent dose. Much of contemporary literature on radiation refers to the rem (Roentgen Equivalent Man). The conversion ratio for rem to sievert is as follows:

1 rem = 0.01 Sv = 10 mSv = 10,000 µSv

1 mrem = 0.001 rem = 10 uSv

Switching the Gamma-Scout® display from sievert to rem is simple (see user guide).

Converting Bq into µSv/h:

For Cs-137 applies at a distance of 1 meter:

1 GBq = 87 µSv/h

100 MBq = 8.7 µSv/h

10 MBq = 0.87 µSv/h

1 MBq = 0.087 µSv/h


100 µSv/h = 1.23 GB GBq

10 µSv/h = 123 MBq

1 µSv/h = 12.3 MBq

0,1 µSv/h = 1.23 MBq

M = 10^6 = 1 million

G = 10^9 = 1 billion

Each material has a certain activity depending on its composition (= measurement of radioactive content), which can be presented in Bq/kg: Bq = decay per unit of time.

Conversion from Bq into µSv/h is possible only in certain specific cases when the material composition and the geometry between the material and the place of measurement are precisely known.

(Distance of the source from the measuring device, shielding of the measuring device, air or other filter between source and measuring device, the chemical form of the nuclide, the type, age and proportion of the isotope in the source …)

The relationship between Bq and µSv/h described above is thus only a very rough indication. An even more tentative indication would be: 1 GBq is equal to approx. 100 µSv/h

There’s no telling where or when you will be exposed to heightened levels of radiation. Travelers are faced with the fact that even a routine transatlantic flight exposes them to three-to-five times the normal radiation level. Plus, certain countries often have higher levels of radiation than users may be accustomed to at home.

The Gamma-Scout® can detect decay isotopes of radon gas (alpha particles).

The Gamma-Scout is equipped with a sophisticated counter tube from the USA that captures all forms of ionizing radiation (>30 KeV), regardless of radiation source.

Independent of the measuring device, there are nevertheless issues relating to the laws of physics that must be taken into consideration:

  1. An exact measurement of ionizing radiation from a source requires the measuring facility to be organized in a way that separates the source’s radiation from ambient radiation, and that the distance between the source and sensing element be exactly defined. This CANNOT be achieved with a mobile Geiger counter. However, Gamma-Scout will certainly detect significant radiation (e.g. 1.0 µSv/h at 0.15 µSv/h ambient radiation). The limit set for occupational health and safety is 20 millisievert per year, i.e. an average of approx. 2.2 µSv/h, although radiation does not occur as an average. The 20 mSv/a relate to 50 weeks * 5 days * 8 hours, adding up to 2000 hours/year. This would equate to 10 µSv/h per working hour. If you divide by 8760 (calendar hours), you reach a limit of 2.2 µSv/h. Based on this, you can say that all measurements below 1.0 µSv/h are “background noise”.
  2. It is important not to confuse dose in µSv/h with activity (scaled in Becquerel). Gamma-Scout calculates the dosage rate from a non-linear correlation of the pulse rate from the counter tube. The basis for the calculation inside the measurement device is a certified cesium-137 emitter (budget Geiger counters work with a simple conversion factor). The activity is defined as 1 decay per second = 1 Becquerel. Because the conversion of an atom into its following atom (via decay) is not necessarily accompanied by the emission of ionizing radiation, the virtually infinite decay patterns make this correlation extremely complex.
  3. The dose (and the associated limits) “measures” the external radiation to which people and the measuring device are exposed. The effect of radiation sources within the human body (from build-up inside the body in organs, blood, etc.) is a wide-ranging and complex medical topic that can only be diagnosed and treated with specialist medical training. It is investigated in very large clinic facilities using different measuring procedures and processes.

Is irradiated fruit contaminated? Or to put it another way: Does irradiation activate foodstuffs and turn them into radiation sources?

No, because the energy used by such irradiation equipment is considerably below 7 MeV, the lowest level at which activation can occur.

Can the Gamma-Scout measure contaminated foodstuffs?

Gamma-Scout measures ambient radiation and radiation caused by contamination. However, identification of the specific gamma energy of the respective isotope is only possible via gamma spectroscopy.

Ambient radiation is comprised of cosmic radiation and environmental radiation (rock, earth, construction materials, plants, animals and people). Cosmic radiation is dependent upon the altitude above sea level and consists of electrons/photons, hadrons (subatomic particles) and myones (heavy electrons). Radiation from the surroundings is largely determined by the proportion of potassium in rock, construction materials, etc. Further contributors are the radioactive isotopes from the uranium and thorium radioactive series. Airborne contamination comes mainly from radon-222 gas (alpha emitter) from the uranium-238 radioactive series.

Furthermore, successful measurement of contamination requires pulse rates to be considerably above the statistical variations of ambient radiation.

Example: Measurement of the subsoil and a food sample with a mass of 1 kg leads to an hourly figure of 1000 pulses. Further measurements with two sensors deliver one result of 1090 pulses/hour and 1200 pulses/hour. Statistical variations in radiation mean that deviations approximately in the order of 3 times the root of the measurement value (3* root 1000 = 95), i.e. >1095 pulses are notable. The first measurement value of 1090 pulses/hour is thus within the statistic, while the second measurement value of 1200 pulses/hour could have been caused by contamination.

Measurable: Potassium-40 in rock, construction materials, fertilizers containing potassium, plants and animals.

Measurable: The gamma content in the progeny of the uranium (U-238, U-235) radioactive series.

Measurable: The gamma content in the progeny of the thorium-232 radioactive series (electrodes with thorium content, old gas mantles).

Measurable: Cesium-137, cobalt-60, radium-226 (old clocks, compasses etc.), limited Sr-90/Y-90.

Not measurable: Tritium, carbon-14, alpha emitters, (beta emitters).

The self-absorption of a material means that alpha emitters cannot be measured and that beta emitters can be measured only to a certain extent because the radiation simply doesn’t reach the Gamma-Scout. As specially prepared laboratory emitters, however, these emitters are measurable.

The Gamma-Scout® warranty is 2 years for defects and malfunction relating to manufacture. This warranty does not apply to damage caused by the customer post-delivery (e.g. a damaged sensor).


Gamma-Scout consumes less than 10 micro Amperes in normal operation, making it exceptionally frugal. Based on your battery resources, the battery can last for more than 10 years. However, energy consumption rises through the use of other functions such as the ticker, alarm, repeated data download or when the device is exposed to extremely high radiation, all of which would lower batter life. Our warranty covers the battery if it runs out within a few months. If the battery is empty or damaged, we offer a repair and replacement service charged for material and labor.

In this case, please return the device to us within 14 days in its original condition. We will then, of course, provide a full refund of the purchase price.

In normal operation, the battery lasts for more than 10 years, although the use of other functions raises energy consumption. Therefore, we cannot guarantee a specific battery life. But it should last years. If it runs out within the first few months, it would be covered by our warranty (see 10 above). In other cases, we offer a repair and replacement service charged for material and labor.

Very. The Gamma-Scout® was developed to the shock standard for wireless handheld devices. Its Novodur® housing is 30 % thicker than that of conventional devices. The housing will not crack, peel,
split or shatter even under extreme temperatures or loads.

The Gamma-Scout® will measure from below ambient radiation level to 1,000 uSv/hr, or 100 mrems/hr. Gamma-Scout® measures changes in radiation levels that would go virtually undetected with older civil defense type devices, and it has an accuracy that is unmatched by cheap radiation detectors.

This depends on the type of radiation (isotype), the intensity of the source and its barrier (shielding). A discrete object emitting substantial radiation can be detected at up to 10 meters. Also, we have found that changes to ambient levels are easily detectable irrespective of distance (e.g. on a plane journey).

You can. Gamma-Scout® meets the European CE standard as well as the American FCC standard and does not cause interference. The X-ray machine at airport security will not damage the Gamma-Scout®.

Sorry, no. Just like a cell phone, the circuit would short out.

Prior to delivery, each Gamma-Scout® undergoes a rigorous factory inspection and calibration protocol. We use a highly stable G-M tube, so it is unlikely your Gamma-Scout® will require calibration during the first 5 years of service. After that, should you desire a factory calibration and test, just return the unit and we will happily check and recalibrate your unit for a modest processing charge.

Please note: The rules of ISO certification for commercial use require calibration of all equipment after 2 years of use. We offer 2 options (both subject to a fee) – a major or minor calibration (see user handbook).

Fundamentally, no. However, for experienced programmers, we have published here the interface data for writing your own read-out software: Knowlege base for developers 

A “Geiger counter” is named for the Geiger-Mueller tube, which is the core component of this device.
This tube contains a thin metal wire through its center. The space around the wire is sealed and filled with gas. The wire carries a charge of 500 volts relative to the tube. An atomic particle or gamma quant penetrating the tube (or an electron knocked out of the wall by X-rays or gamma rays) tears electrons out of atoms in the gas. Because of its high positive voltage, the wire attracts those electrons, which gain energy in the process. They collide with atoms, releasing more electrons, until the process cascades into a “waterfall” which produces an easily detectable pulse of current.

The Gamma-Scout® is a Geiger counter. The principle is that high-energy radiation penetrates a “counter tube” containing a gas of a specific composition held in a vacuum. The radiation “ionizes” molecules, causing a small current flow which is counted at the cathode. Despite all the protective capacitors on the circuit board, strong high-frequency fields can cause ionization that does not originate from a,b,c radiation. The two most common causes known to us are a cell phone within a few centimeters of the Gamma-Scout®, which develops a relatively strong field when transmitting, or certain fluorescent lamps, which develop such a field on lighting up. Removing the cell phone from the direct vicinity of the Gamma-Scout® removes the interference.

see point 4: “What are the Gamma-Scout® units of measurement?”

The Gamma-Scout® is able to measure X-ray radiation as stated. When the radiation is pulsed, the average is correspondingly lower. To secure reasonably accurate results, measurement should be conducted for at least ½ hour. If the only requirement is to detect a leak, a shorter period will suffice, although the measurement will be less accurate.

Ionizing radiation is subject to major statistical variations in this area of brief measurement. Only a few pulses are measured over a period of minutes and converted into dose. You want to take a quick reading and not wait for, say, an hour in order to avoid these variations. The “average daily value” (activity symbol) eliminates short-term variations or you can switch to daily or weekly figures to establish that the underlying figure is extremely stable.

(Prof. Dr. Erich Foßhag, Mannheim University, Faculty of Process and Chemical Technology, Institute for Physical Chemistry and Radiochemistry).

The dead times for the counter tubes we use are LND 712 = 90 microseconds, Centronic ZP 1401 = 90 microseconds and are therefore in line with standard calculated values of approx. 100 microseconds.

In the medical sector, the energies used are often around 60 KeV and are clearly detectable with the counter tube open. It is more difficult to draw a conclusion if the radiation hits the device from the side or from above, as very little of 60 KeV will penetrate. Measurements with Ba-133 (main line 356 KeV) show roughly 50 % of the value measured with the open counter tube.

X-rays and gamma rays are considered wave radiation. Gamma rays are generated in the nucleus of the atom, while X-rays originate in the atom’s shell.

Put simply, there is no difference between the effects of X-rays and gamma rays (at the same energy).

Attached is a spectrum from a variable X-ray source with Am-241 and 60 KeV excitation energy as well as several different X-ray lines generated by the absorber barium.