Also for radiation surveys, two portable Victoreen Model 470A Panoramic Survey Meters are currently in use. Their detector is an unsealed, air ionization chamber and they have a wide range of exposure rates detected (from 0.1 mR/hr to 1000 R/hr).
This is a photo of an Area Radiation Monitor installed at the Injector Tunnel. Local alarm indication is accomplished by a bright amber light, a bright red light and an audio signal, that provide signals of internal failure, alarm and radiation levels that exceed a pre-fixed value.
This screen is created with the EPICS medm (Motif Editor and Display Manager) tool, to enable the operator of maintaining a constant overview of radiation levels at the Injector Tunnel while the beam is on.
In the diagrams above, we have an example of radiation data from the area monitors obtained with the use of EMS (Epics Monitoring System). In the upper part, a radiation source has been used to produce different exposure rates arround the area monitor at a given time interval. The lower part has been obtained during a beam test, where the beam current was gradually increased affecting respectively the exposure rate level in the Injector Tunnel.