| 摘要 |
1422748 Counting particles; correcting counts CONTRAVES AG 20 Aug 1973 [15 Sept 1972] 39243/73 Heading G4D In a counting apparatus for determining the concentration of particles in an electrically conducting liquid extra pulses are fed to the counter according to a predetermined function of the accumulated count to compensate for errors, e.g. due to overlapping particles. A predetermined quantity of the conducting liquid is passed through a capillary restriction in a cell MZ; the low conductivity particles produce resistance fluctuations in the cell which are converted to pulses a. A bi-stable US 1 diverts half the pulses b to an OR-gate T 2 and intervening pulses to a variable divider US 2 which delivers a proportion of the pulses c via an AND-gate T 1 to the OR-gate T 2 . The pulses b + c are accumulated in counter ZW and the count in the highest order Z 3 controls a function generator FG which adjusts the ratio of the frequency divider US 2 such that a greater proportion of pulses c are delivered as the accumulated count increases. This corrects for the statistically higher chance of overlapping particles at higher concentrations. |
