Which meter is better for high levels of radiation - Geiger or Ionization?

• A. Geiger
• B. Ionization
• C. Neutron detector
• D. Thermoluminescent dosimeter

Answer: (B)

When you need to gauge high radiation levels, you want a detector whose reading stays proportional to the actual dose rate even as intensity rises. A Geiger-Mueller counter detects individual events and outputs a pulse for each one, but it has a dead time after every pulse. At high radiation rates, many events occur during that dead time, so the instrument undercounts and the response becomes non-linear. An ionization chamber, on the other hand, measures the current produced by ionization in the chamber gas, which is essentially proportional to the dose rate. This provides a linear, real-time response across a wide range of intensities and remains reliable at high levels. Thermoluminescent dosimeters gauge total dose over time and aren’t suitable for immediate high-rate readings, and neutron detectors are specialized for neutrons rather than general high-level gamma exposure.