SELF-CLEANING APERTURE TUBE FOR COULTER STUDY APPARATUS AND ELECTROLYTE SUPPLY SYSTEM THEREFOR

1479901 Electro-physical measurement; particle analysis COULTER ELECTRONICS Ltd 23 Sept 1974 [26 Sept 1973] 41368/74 Heading G1N(C) In a Coulter type particle analyzer, a "twochamber" tube is provided whereby clean electrolyte can be flowed past the aperture to waste, in a manner similar to that disclosed in Specification 1341336 and a constriction in the flow-path is arranged to increase the velocity behind the aperture. OVERALL SYSTEM FIG. 1. A double tube 13 is sealed into a coupling block 19 attached by screws 59 to the head-block 58, for easy interchange. The electrolyte system is electrically isolated from waste 42 and supply reservoir 52 by drip feed tanks 24, 29. The sample and electrolyte are moved through the apparatus by vacuum applied to the waste drip tank 24. The clean electrolyte flow is regulated by a constriction 27. Several variations of double tube construction are disclosed with reference to Figs. 2 ... 13 which are substantially self explanatory. Figs. 2, 5, 6, 7 only are shown as typical.