Abstract: A bulk material analyzer of the type in which the bulk material is transported through the material analyzer assembly on a conveyor belt between at least one radiation source and at least one radiation detector, includes a plurality of lower and upper modules that contain radiation shielding material and are so shaped as to define a passageway for the conveyor belt between the upper modules and the lower modules when the upper modules are placed on the lower modules. A primary centrally located lower module also includes the radiation sources and a primary centrally located upper module also includes the radiation detectors. Some of the outwardly located modules contain less radiation shielding material. The radiation shielding material includes a plurality of personally portable blocks. The conveyor belt is supported by compressed air passed through central upper wails in the outwardly located lower modules.

Abstract: A calibration block is used for calibrating a bulk material analyzer that has an activation region in which bulk material is received for analysis and a chute for passing the bulk material through the activation region. The block is dimensioned to be of almost the same cross-sectional size as the interior of the chute and extends both above and below the activation region when inserted in the chute. The calibration block is manufactured by (a) providing a mixture of known materials of known proportions that do not chemically react with each other, including a bonding agent; (b) homogenizing the mixture to make a thick paste in which the known materials are bound without segregation of known materials that have different densities; (c) molding the homogeneous mixture into the shape of a block having predetermined dimensions; and (d) solidifying the molded mixture to provide the calibration block.

Abstract: A complete PGNAA bulk material analyzer is self contained in a sealed and air conditioned housing. Bulk material is channeled by an open-ended vertical chute having a one-foot-by-three-foot cross-sectional dimension through an activation region between three neutron sources and two gamma ray detectors. The sources are symmetrically disposed on one of the three-foot long sides of the chute from one end of such side to the other. The detectors are symmetrically disposed on the opposite side of the chute between positions opposing the positions of the sources on the one side of the chute. The chute is dimensioned to enable free flow of various bulk materials. It handles coal of up to a top size of four inches and with typical surface moisture contents and agglomeration characteristics. The relative disposition of the sources and detectors results in the measurements being independent of the lateral distribution of the bulk material within the chute.