OFF-AXIS RESPONSE FOR PARTICLES PASSING THROUGH LONG APERTURES IN COULTER-TYPE COUNTERS
OFF-AXIS RESPONSE FOR PARTICLES PASSING THROUGH LONG APERTURES IN COULTER-TYPE COUNTERS
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DOI:
10.1088/0957-0233/1/6/001
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发表时间:
1990-06-01
影响因子:
2.4
通讯作者:
FEDER, J
中科院分区:
文献类型:
--
作者:
BERGE, LI;JOSSANG, T;FEDER, J
A novel modification of the resistive pulse technique (Coulter principle) has been used to investigate how the measured resistance pulse amplitude depends on the off-axis particle position in long pores. By pressure drive, a particle enters a current-carrying pore and an increase in resistance proportional to the particle volume is detected. When the particle exits the pore, the pressure is reversed such that the particle re-enters the pore and the same particle can thus be studied for a long time. In Poiseuille flow, solid spheres migrate to an off-axis equilibrium position and this non-linear hydrodynamic effect has been utilised to study how the measured pulse amplitude from a single particle flowing back and forth through a pore increases when the particle migrates closer to the pore wall. The increase in pulse amplitude corresponding to a radial particle displacement from the pore axis to the wall is found to be less than 10% for all particle and pore sizes studied. This is considerably less than predicted by the off-axis upper-limit theory of Smythe.