Abstract: A system for measuring the size distribution of particles on which radioactive atoms are attached including: an air flow channel for receiving an influx of the radioactive atoms, a fan for controlling the air flow rate in the channel, one or more wire mesh screens in the channel, and alpha particle detectors located in the channel so as to detect the radioactive atoms. The outputs of the detectors may be connected to a computer for analysis of the outputs.

Abstract: A health physics instrument simulator system permitting an operator to simulate measurement of radiation levels of a plurality of radiation types includes a memory for storing first data corresponding to an n-dimensional training space representing a predetermined physical location, second data defining a radiation source including source strength, source type and source location with respect to the training space and radiation intensity data based on the second data, where each of the radiation intensity data corresponds to one respective location in the training space, a selecting device for selecting a predetermined simulated radiation sensing instrument, a pointing device for identifying a location within the training space defining a current location of the simulated radiation sensing instrument and a display for displaying both an instrument display corresponding to the simulated radiation sensing instrument and radiation intensity data corresponding to the current location in the training space.

Abstract: A health physics instrument simulator system permitting an operator to simulate measurement of radiation levels of a plurality of radiation types includes a memory for storing first data corresponding to an n-dimensional training space representing a predetermined physical location, second data defining a radiation source including source strength, source type and source location with respect to the training space and radiation intensity data based on the second data, where each of the radiation intensity data corresponds to one respective location in the training space, a selecting device for selecting a predetermined simulated radiation sensing instrument, a pointing device for identifying a location within the training space defining a current location of the simulated radiation sensing instrument and a display for displaying both an instrument display corresponding to the simulated radiation sensing instrument and radiation intensity data corresponding to the current location in the training space.

Abstract: A system for determining the health risk, due to alpha emitters attached to particles of various sizes, these alpha emitters being due to the level of radon, to persons within an environment where radon may be present. In one embodiment, a sample of air is passed through a filter element having a collection characteristic such that essentially all particulate material, with their associated radon progeny, is removed from the air. The alpha particles emitted by the decay of these radon progeny are detected with an appropriate alpha particle spectrometer. The realtime resolving of the energies of individual of the daughter atoms permits a determination of the working level or PAEC associated with the radon. In those instances where lung dose is to be determined, the filter element has two portions. The first portion is designed to remove particles in a manner like that which occurs in the human nasal passage.

Abstract: A system for monitoring or controlling the level of radon in indoor air, based upon measuring alpha particles due to the decay of radon or its daughter atoms. In one embodiment, the alpha particle decay of radon itself is detected and analyzed to control a vent in the heating and air conditioning system to automatically keep the radon level below a preselected level. In another embodiment, the daughter atoms .sup.218 Po and .sup.214 Po are collected from the indoor air and their alpha particle decays are analyzed to provide a sensitive monitor of radon levels or to control vents in the HVAC system to reduce radon concentrations to permissible levels. In addition, the system provides information on the quality of the air filter and indicates when it needs servicing.