US Civil Defense CD-39461 Rad Counter/Pocket Dosimeter Pen

The US Civil Defense CD-39461 Rad Counter, also known as a pocket dosimeter pen, is a compact device designed to measure cumulative exposure to ionizing radiation. Introduced during the Cold War era, this model was widely distributed to military personnel, civil defense workers, and emergency responders as part of nuclear preparedness programs. The dosimeter resembles a pen and is worn in a pocket, allowing for continuous monitoring of radiation exposure over time. It operates using an internal ionization chamber and includes a built-in scale visible through a small window, which displays the total dose received in Roentgens. The CD-39461 model is constructed from durable metal and typically features a clip for secure attachment to clothing. It requires a separate charging unit for resetting the scale. These devices were standard issue for civil defense organizations from the 1950s through the 1980s and remain of interest to collectors of Cold War and military equipment.