Which detector is commonly used for survey measurements and contamination monitoring via pulse counting?

• A. Ionization chamber
• B. Scintillation detector
• C. Geiger-Müller counter
• D. Semiconductor detector

Answer: (C)

The Geiger-Müller counter is built around a gas-filled tube that produces a discrete electrical pulse for each ionizing event. This pulse-counting behavior makes it ideal for quick surveys and contamination monitoring, because you can read a direct count rate and instantly tell if radioactivity is present and at what level. It’s portable, rugged, and inexpensive, which is why survey teams use it to sweep areas or surfaces for contamination and to get rapid feedback on activity levels. It’s not intended for precise energy measurements or dosimetry, but for simply detecting and counting events, it excels. Other detectors either measure dose via a continuous current or provide energy information, which isn’t as convenient for straightforward survey counting.