USGS - science for a changing world

St. Petersburg Coastal and Marine Science Center

St. Petersburg Coastal and Marine Science Center > Research and Support Capabilities

Research and Support Capabilities at the St. Petersburg Coastal and Marine Science Center

RAD7 Unit Specifications

FEATURE Specification
MULTI-MODES Continuous Radon Gas Monitor; Long-term/Short-term screener; Sniffer, with small tube "snout", to search for radon and thoron entry points.
MEASUREMENTS Measures radon in air, soil, and water (with RAD H2O accessory)
SENSITIVITY Monitor: 0.7 counts/min/pCi/l; Boosted by the High Gain Modification (i.e. greater sensitivity) and Large Chamber (long-term stability)
RANGE 0.1 ----> 10,000 pCi/l (4 ---> 400,000 Bq/m3)
MEMORY 1,000 radon concentrations, and associated data. Can be read out on LCD, downloaded to PC and/or printed out on HP IR printer. Summary of run shows high, low, average and standard deviation of readings.
PRINCIPLE OF OPERATION Electrostatic collection of alpha-emitters with spectral analysis.
BUILT-IN AIR PUMP Nominal 1 liter/minute flow rate. Inlet air filter; Inlet and outlet air connectors.
SPECTRUM READOUT* Pulse height spectrum of alpha distribution verifies radon/thoron, and also shows the RAD7 is operating properly. Accurate determination of the alpha particle energies creates a radon signature that allows discrimination of radon and thoron's alpha particles from those of other isotopes.
FAST LOW-LEVEL READINGS* In Continuous Monitor mode, RAD7 measures the EPA action level of 4 pCi/l in just 1 hour (60 minutes), with standard deviation of 10%. Since the RAD7 has virtually no background, it has a much lower detection threshold than other electronic detectors, easily measuring down to 0.1 pCi/l
RECOVERY IN MINUTES* Recovers from high radon exposure with a 3.05 minute half-life: to less than 10% of peak value in 12 minutes; to less than 1% of peak value in less than 30 minutes. Drops from 20,000 to 1 pCi/l in one hour.
AUTO MODE* This setting starts a test run in Sniff mode, then switches to Normal mode after the first 3 hours. No more waiting for equilibrium. Gives quick response, followed by statistical precision.
CONTINUOUS UPDATING* Gives continuous update of radon levels so you can see the trend at all times, not just at pre-set intervals. COMPUTER LCD DISPLAY 2 line X 16 character, alpha-numeric. easy to read
POWER AC/Battery powered - 5 AH 6V batteries. Automatic charge when plugged in and switched on. Continuous battery operation: 72 hours in Monitor mode
PRINTER Hewlett-Packard Model HP 82240B RS-232 PORT Computer/modem hookup

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Feedback
Page Last Modified: December 02, 2016 @ 11:56 AM (JSS)