RCL Slide Rule (1950s)

RCL Slide Rule (1950s)

This slide rule was distributed by Radiation Counter Laboratories, Inc. (RCL) of Chicago, Illinois. 

It's had several functions. Given the half life of a nuclide and an elapsed time, it calculates the fraction of the original activity that remains. For a specified count rate and dead time, it determines what fraction the observed count rate is of the actual count rate. For a specified number of counts and count time, it calculates the standard deviation of the count rate. It converts density (e.g., g/cm3) and linear thickness (e.g., cm) to an aerial density (e.g., g/cm2) and vice versa. Finally, it will estimate beta particle energies for a specified range (mg/cm2).

Size: 3.25" x 9.5" (cardboard)


RCL. Use of the RCL Slide Rule. Instruction Sheet. Copyright date 1949.