Radalert 50 Nuclear Radiation Monitor

Health and safety instrument that measures alpha, beta and gamma radiation.  Checks for leakage from X-ray machines and other sources.  In mR/h mode switch position the numeric display shows the radiation level from 0.01 to 50 mR/h.  In CPM mode switch position shows  the radiation level from 0 to 50,000 counts per minute (when x 1000 is shown, multiply the numeric reading by 1000 to get the complete reading).  In TOTAL mode switch position shows the accumulated total of counts starting when the switch is turned to this position, from 0 to 60,000 (when x1000 is shown, multiply the numeric reading by 1000 to get the complete reading).  Uses a Geiger-Mueller tube (LND 712 or equivalent) to detect radiation (this geiger tube has a thin disk of mica on its end, which alpha radiation can penetrate).  Audio output is to an external speaker, amplifier, or tape recorder using a 2.5 mm plug.  The data output port is to a computer, data logger or other device using a 3.5 mm stereo plug.

Here you find 1 models, 1 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from IMI, International Medcom Inc.; Sebastopol, CA