Nuclearule by Nuclear Chicago (ca. 1958-1965)

The Nuclearule was originally produced by the Nuclear Instrument & Chemical Corp., in 1949 or 1950. It was described then as follows "The "Nuclearule" calculator is a special circular slide rule with scales for use in radioactivity calculations. It can be used for computation of count rate, statistical error, coincidence loss, sample activity vs half-life, and radiation flux after passage through absorbers."
Nuclearule by Nuclear Chicago (ca. 1958-1965)

From the General Description in the operating manual: "One side of the rule, called Side I, gives the relationships between the register reading COUNTS of a scaler, the SCALE FACTOR of the scaler, the elapsed TIME in making the count, the COUNT RATE, and an approximation of the various statistical errors. The other side of the Rule, called Side II, gives (1) the relationships between COUNT RATE, RESOLUTION TIME, and COINCIDENCE LOSS; and (2) the ACTIVITY of a source as a function of the number of HALF LIVES or as a function of the number of half thicknesses of absorbers." The above photo shows Side II.

Size: 5.75" diameter


  • Advertisement, Nucleonics June 1950, page 84.
  • Nuclearule Calculator Operation and Maintenance Manual. Nuclear Chicago Corporation. November 1958.