The Linearity and Response of Focussed Apertures

Abstract

Practical experience of particle size analysers using the Coulter principle shows that for measurements made over a range of 2% to 60% of the aperture diameter, the aperture responds linearly to particle volume at least for spheres. In this paper it is shown that the response of a focussed aperture is not significantly different from an unfocussed aperture. It is also shown that a simple linear equation of response successfully applied to a COULTER COUNTER® model ZM in a previous paper, can be used to predict the calibration constant of a new wide range instrument, the COULTER® MULTISIZER.

Impedance-Based Flow Cytometry for the Measurement of Microparticles

“…The linear range for accurate particle measurements is between 2% and 60% of the flow cell aperture diameter. 25,26 Thus for the standard 125-mm flow cell chamber, the lower level of accuracy for sizing is $2.5-mm microns. To detect submicron particles, the Quanta flow cytometer has been refitted with smaller (25-or 40-mm diameter) flow cells.…”