Device for measuring particles in a fluid

摘要

An improved particle analyzer in which a broad measuring beam and a narrower, parallel triggering beam of electromagnetic radiation are sent through a stream of particles. The light scattered by the particles is detected and recorded. At the recording a coincidence signal caused by scattered radiation from the triggering beam ensures that only those particles are counted which have traversed the triggering beam and for this reason the core of the measuring beam. The improvement consists in the use of a triggering beam outside of the broader measuring beam. According to a further improvement the shape of the measuring beam is smaller in the flow direction of the particles than in a direction perpendicular thereto. In this way the analyzer is better suited for the use of one color laser light and higher particle velocities.