This device allowed the Apollo 11 astronauts to determine the radiation in the crew compartment. It was fully portable, self-contained, and provided a direct reading of radiation dose rates calibrated in rads/hr. In the event of a radiation emergency (such as a solar flare) it could be used to find a habitable, low-dose region within the spacecraft. During flight it was clamped in a bracket mounted to the Guidance and Navigation conditioning panel.
This unit flown in the Command Module during the Apollo 11 mission and was transferred to the Smithsonian in 1970.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.