Abstract: A measurement system (45) includes a tank (46) having an inlet and outlet (47, 48) through which a sample (49) flows prior and subsequent to measurement. A stirrer (50) disposed near the base of tank (46) maintains a well mixed solution within the tank. Two immersion probes (52, 53) extend downwardly into the tank and include respective support tubes (54, 55) and sensor portions (56, 57). The sensor portions include respective gamma-ray transmission gauges and four pairs of ultrasonic transducers operating at different frequencies. Accordingly, probes (52, 53) allow the measurement of attenuation and velocity of high and low frequency ultrasound through the sample as well as measurement of attenuation of electromagnetic radiation through the sample. These measurements are utilized to derive an estimate of the solute concentration, particle size distribution, concentration of solids and suspension and the solute concentration of the sample.

Abstract: A method and apparatus is disclosed for determining the moisture content of a substance irradiated by a fast neutron and gamma ray source wherein a fast neutron moderator is positioned in the path of the fast neutrons and gamm rays transmitted through the substance. A unitary thick Li glass or LiI glass detector is positioned behind or surrounded by the fast neutron moderator and detects both slow neutrons and gamma rays. Simplified counting circuitry utilizing a single channel analyser determines the intensities of the detected slow neutrons and gamma rays enabling the moisture content of the substance.

Abstract: Apparatus and methods for producing a signal or signals related to the moisture content of a substance using impedance, radio frequency loss or dielectric loss techniques are disclosed. Apparatus and methods for producing a signal or signals related to the density and/or thickness of a substance using backscattered gamma-rays are described. Apparatus and methods using a combination of a.c. impedance, radio frequency or dielectric loss and backscattered gamma-ray techniques for producing signals related to the moisture content, density and/or thickness of a substance are also described. Means and methods for determining the moisture content, density and/or thickness of the substance from the signal or signals are disclosed. The apparatus and methods are particularly applicable to determining the moisture content, density and/or thickness of coal and coke.

Abstract: An apparatus and method for quantitatively measuring the concentration of a first element or group of elements having substantially similar atomic numbers in a matrix comprising other elements having substantially different atomic numbers to that or those of said first element or group of elements is diclosed. The apparatus comprises(i) a source yielding .gamma.-rays, of sufficient energy for pair production;(ii) detecting means being associated with said source and being capable of detecting 0,511 MeV annihilation radiation;(iii) first measuring means for making a measurement of or proportional to bulk density;(iv) shielding means interposed between said source and said detecting means thereby reducing the intensity of direct source .gamma.

Abstract: The present invention discloses a method and apparatus of elemental analysis which finds particular application in the on-line analyses of the specific energy (calorific value) of coal or coke by the determination of carbon content. Analysis is achieved by a comparison of the output of neutron inelastic scatter which produces first .gamma. rays and of scatter of second .gamma. rays. Preferably 4.43 MeV carbon .gamma. rays are used and, in addition, one or more of moisture, ash, or hydrogen content of coal or coke can be measured using 2.2 MeV hydrogen capture .gamma. rays. The method and apparatus have the advantage of providing a compensated count rate that is essentially independent of sample compaction.