How is the term "grab" defined in the context of radon measurement devices?

In the context of radon measurement devices, the term "grab" refers to devices that take immediate readings of radon levels. This type of measurement provides a snapshot of the radon concentration in the air at a specific moment in time, rather than over an extended period. Grab sampling is useful for quickly assessing radon levels, particularly when immediate results are needed, such as in emergency situations or when verifying expected radon levels in specific areas.

Other types of measurement, such as those that monitor long-term exposure or capture averages, do not fit the definition of grab sampling. Long-term measurement devices are designed to gather data over days, months, or even longer, providing a more comprehensive understanding of radon exposure over time, rather than a single instantaneous reading. Similarly, devices that measure peak levels focus on capturing the highest concentrations over time, while averaging devices collect data over a period and calculate a mean value. None of these approaches give the immediacy and specificity that the grab method provides in radon measurement.