What is the advantage of a Geiger counter?

• A. Measures total energy of radiation
• B. Can detect single gamma photon or beta particle
• C. Is the most accurate dosimeter
• D. Measures radiation dose rate only at high levels

Answer: (B)

Geiger counters are most useful because they register a pulse for each ionizing event that occurs in the detector gas. That means they can detect single particles or photons, such as a single gamma photon or beta particle, turning that solitary event into a countable signal. This makes them highly sensitive to the presence of radiation even at low levels, which is the key advantage. However, they don’t measure how much energy each event deposits, so they can’t provide energy spectra or precise dose calculations. They’re great for indicating whether radiation is present and giving a rough count rate, but not for accurate dosimetry or energy measurement.