Gamma Only Version of Zeus Survey Meter (ca. 1947-1948)
The Zeus was developed by Francis Shonka at the University of Chicago's Metallurgical Laboratory during World War II, and like its descendent, the Juno, the Zeus employed an ionization chamber to measure alpha, beta and gamma radiation. This example seems to be a Zeus that has been modified to serve as a gamma-only survey instrument. As such, it reads out in mR/hr.
It was manufactured for the Atomic Energy Commission (AEC) by the Rauland Corporation and given the AEC designation SIC-3B (the Rauland Zeus was the SIC-3C). Whether or not it was given a nickname (such as the Zeus or Juno) is not known since I have not been able to find any specific information about this device.
It is almost certainly described in the first edition of the AEC Radiation Instrument Catalog (which I don't have). That it is omitted from the 1950 second edition of the catalog suggests that it was no longer being manufactured.