The Commander's Radiation Guide (ca. 1960s)
The Commander's Radiation Guide was produced by the West German slide rule manufacturer, Nestler. As can be seen in the following photo, it is also described as the "Fission Fragment Fallout Decay and Dose Guide." The back side of the calculator (not shown) employs the logo for the U.S. Army Chemical Corps which indicates that it was manufactured under contract for the Army.
Quoting the Foreword in the Instruction pamphlet: "The ability of units and individuals to survive and remain combat effective in a nuclear war will depend, in large measure, on the immediate actions which they take when confronted with radioactive hazards. The Commander's Radiation Guide provides the field commander with a valuable tool for the rapid evaluation of radiological situations."
The Radiation Guide is used to perform a variety of calculations. For example, given a measured exposure rate at a specified time, it will calculate the exposure rate due to fallout at any other time. It can be used to normalize exposure rate measurements made at different times to a standard time (usually one hour after the explosion). It estimates the exposure to personnel as a result of working in an area at specified times after an explosion. It estimates the decay of neutron induced gamma activity. Finally, a table on the back side of the calculator indicates the approximate reduction in the radiation exposure that could be expected in various shelters: a frame house, basement, foxhole, APCs, tanks and bunker. In essence, it is a different (earlier?) version of the Army's ABC-M1A1. Unlike the Commander's Radiation Guide however, the ABC-M1A1 did not estimate the decay of neutron activation products.
The publication number in the instruction pamphlet, would seem to indicate that the pamphlet was produced in March of 1959.
Size: 4" diameter
Instruction Pamphlet for Commander's Radiation Guide. AGL (1) 3-59-13M-70955. No date.