Abstract: A portable apparatus for measurement of nuclear radiation, particularly beta particle radiation due to contamination, of a worktop or bench, comprises a plastic scintillator sheet mounted in the base of a housing, a photomultiplier within the housing, optically coupled to the plastic scintillator sheet, and a rate-motor or counter connected to the photo-multiplier. A pump is also provided, to reduce pressure between the work surface and the plastic scintillator sheet to substantially below atmospheric pressure, so as to increase the mean range of the radiation. Accordingly, the base of the housing is also fitted with a sealing ring.

Abstract: A method of and an apparatus for human bone density determination in vivo. .gamma.- or x-ray radiation of two different photon energies is scanned across the human body part to be examined. For the two photon energies, the logarithms of the intensities of the radiation transmitted through the human body part are determined simultaneously. The logarithm values obtained are processed on line such that the ratio of these values is changed by a predetermined factor. The processed values are subtracted from each other to produce a simultaneous output value which is integrated to give an examination result proportional to the bone tissue content expressed as weight per length unit in a direction perpendicular to the scanning direction while being independent of the surrounding soft tissue.

Abstract: An apparatus for continuously measuring with safety and high accuracy the calorific power of a sample containing hydrocarbon compounds and sulfur, such as crude oil and petroleum products. The apparatus supplies two energy levels of radioactive rays to be absorbed by the sample, a first supply of the radioactive rays having an energy level at which the mass absorption coefficient of carbon differs from that of hydrogen, and a second supply of rays having an energy level at which the mass absorption coefficient of carbon is approximately equal to that of hydrogen. The first rays yield a signal varying with the concentrations of hydrogen, carbon and sulfur in the sample, while the second rays yield a signal varying with the concentration of sulfur in the sample. The signals are density compensated, and mathematically correlated according to a predetermined arithmetic formula to determine the calorific power of the sample hydrocarbon compound.