Neutron Survey Meters
The Model 12-4 consists of a count rate meter with a removable detector. The detector assembly consists of a 1.6cm by 2.5cm BF3 proportional tube, surrounded by 0.0038cm (0.0015") thick cadmium shield, within a 22.9cm (9") diameter polyethylene moderator. This assembly provides an approximate inverse RPG response curve for neutrons ranging from thermal through 10MeV. Efficiency for AmBe neutrons is approximately 30cpm/mrem/h. Gamma sensitivity at Cesium-137 is less than 10cpm through 10R/h.
The Model 15 is designed to detect alpha, beta, gamma and neutron radiation. It consists of a count rate meter with a removable thin-end window alpha, beta gamma probe and a BF-3 neutron proportional tube detector with a 3" diameter cadmium-lined moderator. The detector can be removed from the moderator for fast neutron response.