The Iospectra® 1320-AO radiation probe is a sensor for monitoring ambient levels of ionizing radiation as part of an environmental monitoring and security system. In its standard configuration, the probe detects beta, gamma, and x-radiation with one channel and energy compensated gamma with a second channel; it can be configured to detect alpha radiation as well. This dual channel configuration is the preferred method for simple alarms, providing information to determine what type of source is involved. The 1320-AO is intended to operate in conjunction with a data logger, the Iospectra® Hawk, or a computer running the Iospectra® 1320 software, which can be configured to provide a user-defined alarm function. Proper installation, use, and maintenance of the Iospectra® 1320-AO probe are essential to ensure safe and reliable data collection.
Applications
Applications include homeland security, community protection, public health & safety, scientific research, and education. Environments commonly monitored for radiation may include border security stations, shipping & receiving depots, ports & docks, customs facilities, medical facilities, nuclear power plants, and public event venues.
Detection of Radiation
Each ionizing event detected by the probe transmits a pulse to the data logger or computer, and the relative radiation level is measured typically in counts per minute. It is normal for a background count to be present due to naturally occurring radiation from both terrestrial and celestial sources. As a general guideline, a background radiation level of 25 to 100 counts per minute may be considered typical, depending on your location and local environmental factors. In the presence of unusual ionizing activity, the count rate will increase.
At very high count rates (above 20,000 CPM), dead-time correction may need to be applied to the program in your data logger or computer. Dead time is 136 μs. For most applications, where the probe is used to detect unusual ionizing activity at low levels of radiation, dead-time compensation will not be a concern.
Technical Specifications
Detector 1: Halogen-quenched “pancake” Geiger-Müeller tube (LND 73126). Effective diameter 1.75" (45 mm). Mica window density 1.5-2.0 mg/cm2
Gamma Sensitivity: 3500 CPM/mR/hr referenced to Cs-137
Beta Efficiency (for 4Π at contact):
14C: 49 keV avg., 156 keV max., 5.3%
210Bi: 390 keV avg., 1.2 MeV max., 32%
90Sr: 546 keV avg., 2.3 MeV max, 38%
32P: 693 keV avg., 1.7 MeV max., 33%
