A radiation detection apparatus includes a scintillation counter, a download control device for outputting a scintillation count to a utilization device, and a hand-held probe including a scintillation detector. The apparatus also includes a connector for connecting the probe to the counter, and a switch assembly removably mounted to the probe. The switch assembly has a first trigger for causing the counter to accumulate a first scintillation count over a first period, the counter to accumulate a second scintillation count over a second period, and the detection apparatus to display the second scintillation count. The switch assembly has a second trigger for causing, upon activation, the download control device to manifest an accumulated scintillation count from the counter. A lack of activation of the second trigger during the display of the second scintillation count causes the counter to resume accumulating scintillation counts over the first period.