POST WAR POCKET DOSIMETER, 1950's

A radiation dosimeter is a pen-like device that measures the cumulative dose of radiation received by the device. It is usually clipped to clothing to measure the actual exposure to radiation.
Magnifying lenses (a low-power microscope) and an illumination lens, helps to read the dose by aiming the illumination lens at a light source and looking into the device.

For personal use, this is the most useful device to measure radiation, because biological damage from radiation is cumulative.

Dosimeters must be periodically recharged. The dosimeter is usually read before it is charged, and the dose is logged, to chart exposure.
In many organizations, possession of the recharger is limited to health physicists to prevent falsification of exposures.

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