| 摘要 |
1,249,470. Measuring particle size. COULTER ELECTRONICS Ltd. 31 Oct., 1968 [1 Nov., 1967], No. 51644/68. Heading G4H. [Also in Division G1] In apparatus for ascertaining that particle size of a particulate system above and below which predetermined fractions of the total mass of the system lie (e.g. the mass median, for equal fractions), a particle scanning transducer 330 working on the Coulter principle generates discrete pulses each of amplitude proportional to the volume of the particle giving rise thereto. The pulses are converted into binary cooled particle size signals which are added or subtracted to a total in a register 304 according as the output from a comparator 334 shows that the particle size signal is greater than or less than a feedback threshold signal T. A multiplier 302 allows different mass percentiles to be selected. At equilibrium, the output of the register 304 represents the required particle volume. A computing circuit 311 calculates the equivalent spherical diameter which is converted to decimal code at 310 and fed to a tape or card printer 370. |
