Abstract: Method for determining the average density or volume percentage of at least one coarse grained component of a multicomponent mixture by gamma transmission analysis, including the steps of irradiating the mixture with gamma radiation from at least one source, detecting the transmitted radiation by means of at least one detector, and evaluating the relation between the transmitted and detected radiation to determine the average density or volume percentage by using a transmission equation applicable to homogeneous mixtures, the evaluation including transforming the values resulting from solving such equation, or a selected term of such equation, with the aid of a correction function which is derived by comparison of corresponding values in the transmission equation applicable to the homogeneous mixtures and in a further transmission equation which is dependent on the particle sizes of the coarse grained component in order to provide a corrected determination relative to that component.

Abstract: A method of and apparatus for ascertaining the volume components of a thrcomponent mixture, according to which the mixture is radiated simultaneously by two gamma sources of different energy. The passed-through radiation is picked up by a common detector, and the detector signals are spectroscoped alone with regard to the components of the two gamma lines. The spectogram is evaluated with regard to the two transmissions and with regard to the extinction coefficient pairs for each of the three components (.mu..sub.k1,.mu..sub.k2),(.mu..sub.s1,.mu..sub.s2),(.mu..sub.w1,.mu..sub. w2) whereupon, with a known length of the transmission distance, the volume parts of the components are calculated as functionV=f[.mu..sub.k1,.mu..sub.k2,.mu..sub.s1,.mu..sub.s2,.mu..sub.w1,.mu..sub.w2 ,t.sub.1,t.sub.2,1].

Abstract: Presence of metals such as copper and nickel being economically interesting etals are determined as to existence thereof in the content of manganese nodules according to a method by means of analysis of the activation gamma spectrum of manganese nodule samples after a neutron irradiation thereon. The sample is irradiated with fast neutrons and from the resulting gamma spectrum the ratio of radiation intensities of two main component parts preferably manganese and iron is taken in order to determine the percentage metal content by way of empirically obtained geochemical correlation-data which reproduce the percentage parts of further elements dependent upon proportional ratio of two main elements of the manganese lumps.

Abstract: For the in situ analysis of marine ore concretions, ore samples are aspirated from the sea floor and introduced in a sample container aboard a carrier body travelling underwater along and in the vicinity of the sea floor. While in the sample container, the ore concretions are exposed to radioactive rays for inducing a secondary radiation emanating from the ore concretions. The secondary radiation is measured for determining the quantity of the individual elements contained in the ore concretions.