What is wrong with a traditional Geiger counter?

Radiation dosimetry means measuring the health risks of a given radiation field. Generally this means measuring X-ray and gamma radiation levels. The traditional low-cost way to to do that is with a gas-filled Geiger tube which simply counts the number of times radiation interacts in the tube. This has a few weaknesses. First, because the tube is filled with gas and not a solid material, X-ray and gamma radiation has a low chance of interacting, meaning low sensitivity to X-ray/gamma. Second, the tube does not know if a low or high energy particle is interacting which means very poor accuracy in most everyday situations. Finally, a Geiger tube gets saturated easily in strong radiation fields, meaning low maximum range in high radiation rate environments, such as those that could occur in a radiological emergency or attack.

What is better about the Better Geiger detector?

Most modern, professional-grade personal radiation dosimeters use a scintillator instead of a Geiger tube. When radiation interacts with a scintillator, it creates a tiny burst of light. By counting these bursts of light and how intense they are, radiation levels can be measured. Unlike a traditional Geiger counter which simply counts, with a scintillator the intensity of each individual bursts can be used to produce more accurate radiation dose information. Additionally, the burst are very short meaning high radiation levels can be measured, unlike a Geiger counter which gets saturated easily. Professional detectors using a scintillator typically have price tags around $1000 and beyond. The Better Geiger was designed from the ground up to be affordable for ordinary people. Furthermore, it was designed to be as simple-to-use and as rugged possible.

Does the Better Geiger measure beta radiation?

Unlike X-ray and gamma radiation, which tend to travel long distances, alpha and beta particles tend to travel a short distance and are easily stopped by solid materials, such as clothing. They are therefore not typically an external hazard (as long as radioactive material is not ingested or inhaled). If a detector is highly sensitive to alpha or beta particles this can cause extreme overestimation of radiation dose.

Both the Better Geiger and a traditional Geiger tube react to beta radiation, but a Geiger tube reacts much more strongly because it is larger. This means a traditional Geiger tube is faster in identifying and locating a beta source, but also that it will give extremely overestimated dose rates when near a strong beta source. The Better Geiger will generally be much more accurate in those situations. Radioactive antiques and minerals are objects which tend to be very strong beta emitters and very weak X-ray/gamma emitters. The Better Geiger can be used to identify those items as radioactive, but not as quickly as a traditional Geiger tube detector. The Better Geiger dose rate measurements near those objects will generally be more accurate than a traditional Geiger tube.

Does the Better Geiger measure alpha radiation?

Some radiation detectors are specifically designed to be very fast in identifying surface contamination, or radioactive material in a place it shouldn’t be like a person’s skin or clothing. These are often referred to as survey meters. In nearly every situation where a surface is contaminated with radioactive material, the material is emitting beta and gamma radiation. Some contaminants also emit alpha particles. By measuring the beta and gamma component, a surface contaminant can be identified.

The Better Geiger can achieve this goal. A traditional Geiger tube is more sensitive to beta radiation, so it will a faster tool for that job, but this is usually not necessary unless large amounts of surfaces are to be checked for contamination, for example in a mass casualty event. Even better than a Geiger tube is a so-called “pancake” style Geiger device, which is even more sensitive than a Geiger tube to beta radiation and often is also sensitive to alpha radiation. These are more expensive and for a professional this might be a necessary tool, but for the average user the added functionality is not typically needed. None of the devices discussed (Better Geiger, traditional Geiger tube, pancake-style Geiger) are suitable for measuring radon concentrations in air. That particular task requires a dedicated device designed specifically for that purpose.

Specifications

(10 μSv = 1 mrem)

  • Dimensions without rubber protector: 73x26x118 mm (2.9 x 1.0 x 4.6 in)

  • Weight, detector only without batteries: 120 g (4 oz)

  • Operating condition range: -10°C to 40°C (14°F to 104°F)

  • OLED display 30x15 mm (1.2”x0.6”)

  • Powered by two AA batteries, typical life >50 hours in normal display mode and >95 hours with dark mode using typical Alkaline batteries

  • Minimum X-ray/gamma sensitive energy: 50 keV

  • Dose rate is automatically energy-corrected according to incoming X-ray/gamma spectrum

  • Maximum dose rate for Cs-137 source: 100,000 μSv/hr (=10,000 mrem/hr = 100 mSv/hr = 10 rem/hr)

  • Estimated dose rate uncertainty ±30% over all energy, direction, and temperature ranges

  • Display modes 1-3 indicate μSv/hr range as NORMAL (0-1), HIGH (1-10), and DANGER (>10)

  • Screen update interval 2 seconds