Abstract: Apparatus for monitoring the mass concentration of atmospheric pollutants above and below a predetermined size. A receptacle has an air inlet and outlet. Air is continuously drawn through the inlet and thence through the receptacle and the outlet. A first collector in the receptacle collects pollutants above the predetermined size. This first collector is movable through a first station and collects pollutants above the predetermined size from the air entering the receptacle through the inlet on successive areas thereof. A second collector in the receptacle collects pollutants below the predetermined size. This second collector is movable through a second station and collects pollutants below the predetermined size from the air which has passed the first station on successive areas thereof. A holder is provided for a first source of radiation which passes through the area of the first collector at the first station.

Abstract: A method and apparatus for concurrently counting a plurality of radioactive samples. The position sensitive circuitry of a scintillation camera is employed to sort electrical pulses resulting from scintillations according to the geometrical locations of scintillations causing those pulses. A scintillation means, in the form of a scintillating crystal material or a liquid scintillator, is positioned proximate to an array of radioactive samples. Improvement in the accuracy of pulse classification may be obtained by employing collimating means. If a plurality of scintillation crystals are employed to measure the iodine-125 content of samples, a method and means are provided for correcting for variations in crystal light transmission properties, sample volume, and sample container radiation absorption.

Abstract: A system for continuously monitoring air for the presence of tritiated water vapor comprising: contacting a predetermined mass flow of an air sample with a predetermined flow of a liquid miscible with tritiated water to transfer any tritiated water vapor in the air sample to the liquid; stripping radioactive noble gases from the liquid with a stream of gas; and analyzing the liquid for beta radiation to determine the presence of tritium. In the preferred embodiment of the apparatus an air-liquid contactor, a gas-liquid separator and a stripper are combined into a single unit with a common outlet for the contacted air and stripping gas.

Abstract: The present invention relates to a method of and apparatus for the radionuclide imaging of the whole body of a patient using an unmodified scintillation camera which permits a patient to be continuously moved under or over the stationary camera face along one axis at a time, parallel passes being made to increase the dimension of the other axis. The system includes a unique electrical circuit which makes it possible to digitally generate new matrix coordinates by summing the coordinates of a first fixed reference frame and the coordinates of a second moving reference frame.

Abstract: An improved method and apparatus for providing an indication of the radiation activity of the radioactive decay products of radium in an environment wherein the alpha particle activity and the beta particle activity at a test site are detected and the detected alpha particle and the beta particle activities provide the indication of the radiation activity of radon and the decay products of radon at the test site. The background radiation activity at the test site is detected, and the detected alpha particle and the beta particle activities less the detected background radiation activity provide the indication of the radiation activity of radon and the decay products of radon.

Abstract: Radioactive iodine is detected in the effluent cooling gas from a nuclear reactor or nuclear facility by passing the effluent gas through a continuously moving adsorbent filter material which is then purged of noble gases and conveyed continuously to a detector of radioactivity. The purging operation has little or no effect upon the concentration of radioactive iodine which is adsorbed on the filter material.

Abstract: The present invention is a detector suitable for an apparatus for the absolute measurement of the mass flow rate of a gas by injecting a radioactive tracer isotope, with a known activity relative to a standard, into the flowing gas and measuring the activity when a small sample representative of the flowing gas is removed at a sampling point downstream of the injection point at a sufficient distance to ensure a homogeneous mixture of the tracer isotope with the flowing gas.

Abstract: In order to measure the level of radioactivity of liquids in a set of vessels, e.g. those employed in a competitive radio-assay, liquid is drawn successively from each one of the set into a measuring region defined inter alia by radiation shielding, so as to fill the region, the measurement takes place in the region, and the liquid is thereafter expelled.

Abstract: A sample of hot fluid under pressure circulating in a main circuit is admitted into a cavity formed within a sampling unit. The temperature and pressure of the fluid within the cavity are brought to the same conditions as in the main circuit and the cavity is then isolated after thermal stabilization of the main circuit. The sampling unit is isolated, then cooled in order to reduce the pressure within the cavity. A supporting shield which normally covers a thin window formed in the bottom cavity wall is withdrawn by sliding and the fluid is analyzed across the window.

Abstract: The present invention relates to a method for use in liquid scintillation measurements to feed an accurately determined amount of radioactive substance to a fluid scintillation system for a calibration measurement. According to the invention an accurately determined amount of radioactive substance is adsorbed to a carrier, which is introduced into the fluid scintillation system. The invention also relates to a carrier for use in the method.