Which detector measures radiation quantity by counting hits but cannot distinguish radiation type?

Which detector measures radiation quantity by counting hits but cannot distinguish radiation type?

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

Answer: (A)

The key idea is counting discrete ionizing events versus measuring total ionization. A detector that counts hits treats each ionizing interaction as a separate event and produces a pulse for each event. That’s exactly how a Geiger-Muller counter works: every ionizing interaction in the gas produces a detectable pulse, so you read out a count rate. It doesn’t provide energy information or identify the radiation type; it simply tallies how many events occur. In contrast, an ionization chamber measures a continuous current that’s proportional to the total amount of ionization happening in the chamber, not individual events. It gives a dose-rate or exposure signal rather than a count of events, and it doesn’t inherently tell you what kind of radiation caused the ionization. Scintillation and semiconductor detectors can give more information about energy and sometimes aid in distinguishing radiation types, rather than just counting events. So, the detector that measures radiation quantity by counting hits but cannot distinguish radiation type is the Geiger-Muller counter.

The key idea is counting discrete ionizing events versus measuring total ionization. A detector that counts hits treats each ionizing interaction as a separate event and produces a pulse for each event. That’s exactly how a Geiger-Muller counter works: every ionizing interaction in the gas produces a detectable pulse, so you read out a count rate. It doesn’t provide energy information or identify the radiation type; it simply tallies how many events occur.

In contrast, an ionization chamber measures a continuous current that’s proportional to the total amount of ionization happening in the chamber, not individual events. It gives a dose-rate or exposure signal rather than a count of events, and it doesn’t inherently tell you what kind of radiation caused the ionization.

Scintillation and semiconductor detectors can give more information about energy and sometimes aid in distinguishing radiation types, rather than just counting events.

So, the detector that measures radiation quantity by counting hits but cannot distinguish radiation type is the Geiger-Muller counter.