公开(公告)号：US3530381A

公开(公告)日：1970-09-22

申请号：US3530381D

申请日：1968-01-15

Applicant: COULTER ELECTRONICS

Inventor： HOGG WALTER ROBERT ,  KLEIN ROBERT IVAN ,  HAYES CARL BURGESS

IPC: G01N15/12 ,  G01N33/49 ,  G01N27/00 ,  G06F7/38 ,  G06G7/14

CPC classification number: G01N15/1245

公开(公告)号：GB1254891A

公开(公告)日：1971-11-24

申请号：GB207869

申请日：1969-01-14

Applicant: COULTER ELECTRONICS

Inventor： HOGG WALTER ROBERT ,  KLEIN ROBERT IVAN ,  HAYES CARL BURGESS

IPC: G01N15/12 ,  G01N33/49

Abstract: 1,254,891. Counting particles. COULTER ELECTRONICS Ltd. 14 Jan., 1969 [15 Jan. 1968], No. 2078/69. Heading G4D. [Also in Division G1N] Analysis of particle.bearing liquid, e.g. by Coulter apparatus, is improved by passing the liquid through parallel channels A, B, C and accumulating pulse counts separately, comparing the counts. so as to discard any count which differs markedly from the others, and averaging the counts which are not discarded. Pulse count accumulators 24, 26, 28 apply potentials increasing with count to comparator amplifiers 80, 90, 100 where each channel is compared with another to give a differential output to threshold devices 84, 94, 104. At the same time the outputs of each pair are added and computed to an allowable standard deviation in parabolic networks 124, 136, 148 which control the threshold devices. Assuming a trouble-free operation the line 64, Fig. 2, shows how voltage increases with time between allowable voltages 208, 210. If, however, one channel is blocked so that its voltage follows the line 66 then the average count voltage follows the line 214. When this voltage crosses the lower limit line 210 then the related threshold device operates. A voting logic network 88 comprises three AND gates, one of which then opens to open the switch 42, 44 or 46 corresponding to the blocked channel so that the averaging network 54 discards the unwanted count. In a modification (Fig. 6, not shown) the allowable deviation is computed from all the channels the counts in which are compared individually with the accumulated average. The threshold devices are therefore individual to the channels. A matrix (231) permits one defective channel to be discarded but if a second channel becomes defective the test is voided.