Compared to Geiger Muller systems, how do ion chamber based survey monitors rate in terms of sensitivity?

Ion chamber-based survey monitors typically have lower sensitivity when compared to Geiger-Müller (GM) systems. This is due to the fundamental operational differences between the two types of detection devices.

Ion chambers operate based on the principle of measuring ion pairs produced in a gas when radiation passes through it. They are most effective for measuring high radiation levels and are generally used in environments where higher dosages are expected, such as in radiation therapy. However, they require a certain threshold of ionization to register a measurement, making them less effective for detecting low levels of radiation.

On the other hand, Geiger-Müller counters are designed to be highly sensitive to a broader range of radiation levels, including very low doses. They can detect radiation events with minimal energy, allowing them to register counts even when the intensity of radiation is quite low.

The distinct operational characteristics of ion chambers and GM systems factor into their comparative sensitivity, affirming that ion chamber-based monitors are indeed less sensitive than their GM counterparts in detecting low levels of radiation. This makes them more suited to applications requiring accurate measurements at higher dose rates rather than for environments where low radiation detection is critical.