A technique for continuously measuring filtration resistance at constant pressure

A device for continuously measuring, at constant pressure, the filtration resistance of different liquid suspensions is described. It is made up of two main parts: flowmeter system and electronic circuit. The flowmeter consists of a capillary tube and a sensitive pressure transducer, and has a time response of 100 ms and a linearity of ± 1 % from 1 μls−1to 200 μls−1. The electronic part allows the calculation and recording of flow versus time and filtration resistance versus the volume which passes through the filter. Principle, technical characteristics of the system and examples of recording with several Red Blood Cell populations are reported.