The RADIAC Slide Rule for Nuclear Fission Products was developed in the early 1950s by B. W. Soole at the Admiralty Research Laboratory in Teddington England and manufactured by Blundell Rules Limited (BRL). Its purpose is the same as BRL's RADIAC Calculator No. 1. In fact, the RADIAC Slide Rule is the predecessor to the RADIAC Calculator. In his paper describing the RADIAC slide rule, B.W. Soole notes: "A circular calculator designed to solve the same type of problem has been described recently by Orr." Soole is referring to Orr's Radiation Dosage Calculator.
This is an extremely heavy duty calculator made of 3/8" thick plastic.
If the exposure rate is measured at a specified time, the slide rule can calculate the exposure rate at any other time. It will also calculate the dose to personnel for specified time intervals after a nuclear explosion. The two slides are reversible. One side of each slide has data pertaining to fallout generated by explosions over the sea, while the other side is used for calculations involving explosions over land.
Size: ca. 2.5" x 12"
Reference
B.W. Soole. The RADIAC slide rule for the computation of external radiation dose from nuclear fission products. Journal of Scientific Instruments Vol. 29 (June): 189-192. 1952.