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 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.
· 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%
· Measurement Range: 0 to 5 mR/hr or 0 to 18,000 CPM calibration check, typical maximum 10 mR/hr or 35,000 CPM
· Window Shield: NCR2/2 Mylar laminated to a copper beryllium screen
· Detector 2: Halogen-quenched energy compensated Geiger-Müeller tube (LND 7128). Effective diameter .36" (9.1 mm)
· Gamma Sensitivity: 1000 CPM/mR/hr referenced to Cs-137
· Measurement Range: 0 to 5 mR/hr calibration check, typical maximum 10 mR/hr or 10,000 CPM
· Temperature Range: -20° to 85°C (-4° to 185°F)
· Power Requirement: 3.0 to 15 V DC
· Current Drain: <1 mA (typical) to 20 mA (max) @ 12 V DC
· Lightning Surge Protection: to 600 W for 1 ms
· ESD Protection: up to 16 kV
· Size (L x W x H): 6.25" x 3.15" x 2.35" (157 mm x 78 mm x 60 mm). Connector adds 0.6" to length.
· L-Bracket: 6.25" x 3.25" x 2.25" (157 mm x 83 mm x 57 mm). Thickness 0.1" (2.54 mm).
· Probe Weight: 21.1 oz. (599 gr.) With Bracket: 25.6 oz. (726 gr.)
· Probe Housing: Anodized aluminum and polycarbonate. Water resistant.
· Cable: Waterproof. RFI-shielded. UV-resistant jacket. 10 meter length.
· Connector: M12 Euro. Waterproof. RFI-shielded.
· Computer Interface: Optional cable with RS-232 or USB 2.0 interface.
· Options & Accessories: replacement window shield, window screen w/o mylar, RS-232 or USB 2.0 cable kit, quick-release pole-mount adaptor, USB data acquisition adapter, calibration fixture
· New! The Iospectra® Hawk (available separately) is a wall-mount monitoring and alarm system that provides power and display for the 1320-AO probe, as well as alarm functions, siren, flashing light, and relay output for HVAC or security system trigger.