SETT ATT AUTOMATISKT KORRIGERA REKNETALSVARIATIONER PA GRUND AV KOINCIDENTA PARTIKLAR I EN PARTIKELANALYSATOR SAMT ANORDNING FOR GENOMFORANDE AV SETTET

摘要

1423021 Particle analysis COULTER ELECTRONICS Ltd 23 March 1973 [27 March 1972 26 Sept 1972] 14242/73 Heading G1N [Also in Division G4] The invention relates to the automatic STATISTICAL CORRECTION of the count from particle analysis apparatus, for errors due to coincidence of particles in the counting zone, by deriving TWO PARTICLE-PULSE COUNTS from the sample and entering them in a suitably programmed computor. The two counts may be obtained from (i) Two (or more) apertures having a known ratio of their "aperture critical volumes" Fig. 2 (not shown) (ii) two (or more) dilutions of the sample fed through a single aperture Fig. 3 (not shown) (iii) an artificial second count generated by delaying the pulse-train and adding it to the original train before counting Figs. 4 and 5 (not shown) (iv) a photo-electric sensor with a variable width light beam adjusted to provide two (or more) sensing zone volumes. Alternatively the apparatus could be programmed to determine a function used in the calculations and termed the CRITICAL VOLUME. The Specification derives the equations which the computor must solve for each of the four methods.