Design criteria were established following a survey among radiac specialists in the three services, and among Laboratory personnel and civil defense instructors. The resulting design includes these features: (1) A lowimpe ance circuit giving 20% accuracy from -40 to +50 C, with no zero drift; (2) A 50-cu in. belt-carried package which satisfied Mil-E-16400 environment specifications; (3) Gamma rate from 1 to 1,000 rad/hr, skin-dose rate to 5,000 rad/hr (from a separable probe), each indicated on several linear meter scales; and (4) A connector for a four-decade, low-range probe, and other possible auxiliary probes. Six prototypes have been fabricated. Work is continuing toward packaging the low-range probe and toward reducing costs of manufacture. (Author).