SabreBPM²
Portable Beta(Alpha) CAM
The Bladewerx SabreBPM² Portable Beta CAM is a lightweight, battery-powered, Alpha + Beta Particulate Monitor that can be used as a portable workplace monitor or a portable CAM for emergency-response assessments. It is designed to provide workers with an early warning of an airborne release of beta emitting particulates.
Using the acclaimed Bladewerx peak-fitting software for radon-background subtraction means more accurate workplace measurement and alarm indications. A self-contained pump, built-in detector head, alarm light, sonalert and battery operation, allow the ultimate in beta air monitoring portability. A solid-state, ion-implanted, silicon detector and reliable 1024-channel multichannel analyzer provide the input for an embedded processor board that performs beta detection and the alpha spectral analysis for radon background compensation and alpha-emitting transuranics. An integrated 7-LPM pump, lithium-ion battery and charging electronics complete the package allowing battery operation of more than eight hours. The SabreBPM² may be configured for either the measurement of special nuclear materials (SNM), or for radon progeny measurements of potential alpha energy concentration (PAEC) in milli-Working Level. Stack monitoring is possible with the In-Line Head Option. The In-Line Head Option can also be used for Iodine monitoring with carbon-impregnated filters.
Features
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Remote monitoring via the wireless RadNet or ASCII options
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Typical sensitivity of 1.0 DAC-h for Chronic and 30 DAC-h for Acute
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Radon Mode displays PAEC in mWL and also logs radon progeny equilibrium
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Less than one false alarm per 2,080 hours of operation
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Weighs less than 9 pounds with a battery life of at least 8 hours
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Significantly reduced false alarms— using alpha peak-shape-fitting technology
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Performs both fast-responding and high-sensitivity measurements
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Can be plumbed to an external pump for higher flow rates and improved sensitivity
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In-Line Head option available for stack or iodine monitoring
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Acute and Chronic dose, concentration, and flow logging as well as spectrum logging
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International version available using SI units and adapted power supply
Alpha Peak-Shape-Fitting
State-of-the-art alpha peak shape fitting is used to separate the spectrum into the contributions from its constituent nuclides and quantify the spectrum counts from radon progeny and optionally up to two isotopes-of-interest. Alpha peak shape fitting is a technique that uses the profiles of multiple alpha isotope peaks to create a composite curve which best fits the actual spectrum counts. Because the individual nuclide peaks are independently determined, the separation of nuclides is impervious to radon equilibrium changes and contributes to a very low probability of false alarms. Precise fitting of the 218Po tail results in excellent sensitivity—superior, in many cases, to instruments sampling at 40 LPM.
Alpha Monitoring
The standard SabreBPM² is capable of monitoring one or two alpha isotopes of interest, simultaneously with beta monitoring. The alpha isotope counts are distinguished from the radon background using the peak-shape-fitting algorithm. Isotopes have individual alarm set points and can also be remotely monitored if paired with the RadNet or ASCII output options.
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If alpha monitoring is not needed, the instrument can be ordered without the alpha-monitoring capability, while still retaining the radon-subtraction feature.
User Interface Display
An integrated 5.5-inch LCD and touch screen displays detailed information on the status and readings while in operation. The dose estimate of the isotope(s) of interest and instrument status are prominently displayed at all times, while a window below either displays the historical readings and battery status, or displays the current spectrum. The user mays switch between the two displays from the View menu.
Data Logging
The SabreBPM² creates log files of both the Acute (from 1- to 30-second detail) and Chronic (1-minute detail) readings, along with spectrum log files at a user-defined logging interval of from 1 to 60 minutes. These log files may be saved in the internal memory, or stored on a removable SD memory card, for later retrieval and review. The log files use the comma-separated-variable (*.csv) format, recognized by most spreadsheet and database software.
Sensitivity and Response Time
The sensitivity of the SabreBPM² is dependent on several factors including, radon background, filter type, flow rate, acute and chronic window settings, and, of course, the energy of the isotope of interest. A beta MDD less than 0.03 DAC-h for Cs-137 using a 120 second acute analysis time in a 15 µR/h gamma background is typical.
Gamma Guard Detector
An internal guard detector is standard, providing real-time compensation for changing ambient gamma background levels. Both radon and gamma subtraction is controlled with a user-set subtraction factor. Standard units offer fixed subtraction when a guard detector is not present.
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Optional Remote Monitoring
With the wireless RadNet Output Option installed, multiple SabreBPM²s report their status and readings to a wireless access point, up to 300 feet away, networked with a laptop or PC running Bladewerx RadNet Client software, or other RadNet compliant client software. This capability allows remote supervisory monitoring, in real-time, of up to ten work areas. Remote monitoring can also be performed with the ASCII Protocol Output Option, either over WiFi or RS-232 connection.
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Radon Mode
The SabreBPM² may be configured for a ‘Radon Mode’ where the instrument will monitor the potential-alpha-energy-concentration (PAEC) of airborne radon progeny. The display units can be configured for either American units of milli-Working Levels (mWL) and WL-h, or SI units of µJ/m³ and µJ-h/m³. Because the individual progeny concentrations are known, the effective (dis)equilibrium ratio of radon progeny can be determined and logged. This feature can provide useful insights into the ‘age’ of the air sampled.