Method and Apparatus for Determining the relative Volume of Crystalline Solids in a Crystalline Solution.

摘要

1,174,438. Measuring relative volume of crystals electrically. HAWAIIAN DEVELOPMENT CO. Ltd. Nov.30, 1967 [Dec.7, 1966], No.54542/67. Heading G1N. The relative volume of electrically non-conductive particles, e.g. sugar crystals, in a conductive liquid is measured by comparing the specific resistance of the solution measured by two electrodes spaced apart by more than the average spacing of the particles, so as to include between them a plurality of crystals, and by two electrodes spaced apart by less than the average spacing of the particles so as to include at the most one crystal. Construction of electrodes The closely spaced electrodes may take the form of a straight glass tube 16, Fig.3, provided with a pointed lower end at which the end 10 of a conductor 30, running through the tube, is exposed to form one electrode. Aligned with the tube 16 is an upwardly directed pointed end of a second J-shaped glass tube 22 having at the pointed end the exposed end 14 of a conductor 32 forming the second electrode. The tube 16 is slidably mounted in a block 24 on tube 22 whereby the spacing of the electrodes may be adjusted. Alternatively the electrodes may be formed by a pair of parallel metal sheets (36, 38, Fig. 4, not shown), separated by an insulating film (46) whose thickness determines the separation of the edges of the plates. The measuring electrodes may be similarly shaped, (Fig. 5), with the electrodes themselves formed by metal discs 6, 8, at the adjacent ends of insulating tubes 48, 54. The tube 54 is, as before, slidable relative to the tube 48 so that the spacing between the electrodes may be adjusted. The spacing of the pairs of electrodes are calculated from a knowledge of the crystal dimensions and the range of relative volumes under consideration. The electrode pairs are arranged in a pipe through which the solution is flowing to provide a continuous indication of the relative volume of the particles. Measurements The electrodes may be connected in an A.C. energized bridge, Fig.6 (not shown), balanced for a particular relative volume. Alternatively the electrodes may be connected alternately to an A.C. supply provided with an ammeter in series and a voltmeter in parallel with the electrodes, Fig.7 (not shown).