A 15 cm long, 1.9 cm diameter, personal dosimeter based on a miniature Geiger-Mueller tube, high-voltage and detection circuitry and an alarming (audio and/or visual) system all of which were potted in epoxy and housed in an aluminum tube. A compact 4V battery housed in the aluminum tube external to the epoxy section, but with a contact to the circuitry, provided the required electrical energy. The version shown here would produce a flashing red signal at a pre-set dose rate. The versions with an audible alarm (chirp) were known as “Chirpee dosimeters”. Versions with a dose range 0-2R/h up to 0-200 R/h were made by this manufacturer.
