Abstract: Time varying measurements indicative of the ratio of mass absorption coefficients of the components of a multiphase flow containing at least two liquid phases at two spaced apart locations are cross correlated to determine liquid flow velocity. The time varying measurements are provided by measuring the intensities of gamma-rays transmitted through a selected volume of the flow at two different gamma-ray energies. At least one of the gamma-ray energies has substantially different mass absorption coefficients in each of the two liquids. Gas velocity, when gas is present, and component fractions of all components are determined using a dual energy gamma-ray transmission technique and with the liquid flow velocity are used to derive mass flowrates.

Abstract: X- or .gamma.-ray scatter assemblies are used in quantitative determination of the concentration of ash in coke or coal. The assemblies each comprise an X- or .gamma.-ray source, an energy sensitive detector to detect X- or .gamma.-rays resulting from scatter in the coal or coke of X- or .gamma.-rays from the source, and shielding means adapted to reduce the intensity of direct X-rays or .gamma.-rays and to collimate partly the beam of X-rays and or .gamma.-rays to ensure maximized matched volumes for all assemblies and deep penetration in the coal. The assemblies are associated with an electronic analyzer adapted to select all or part of the detected X-ray or .gamma.-ray spectrum, thereby modifying the output of the assemblies. Two or more assemblies are employed in an apparatus and method for analyzing coal or coke.

Abstract: A method for determining the solids weight fraction of a slurry especially a coal slurry is described based on a measure of the concentration (wt/wt) of hydrogen in the slurry by neutron transmission or scatter. Accuracy of the method can be improved by combining the neutron measurement with a .gamma.-ray transmission or scatter measurement, and further improved by including a measurement of X-ray scatter or transmission. In the last mentioned case the mineral matter content of the coal in the slurry can also be determined.