Method and apparatus for the simultaneous measurement of data, including velocity, relating to submicronic particles in a state of flow in a fluid

摘要

The same assembly is used to first record the homodyne spectrum from the light diffused from a single beam FL.sub.2, with a mask D.sub.1 masking the beam FL.sub.1. On the passage of a critical frequency f.sub.c, mask D.sub.1 is removed, the aperture of a diaphragm D.sub.2 is reduced, and the heterodyne spectrum produced by FL.sub.1 and FL.sub.2 is recorded as received by a photomultiplier PM and a spectrum analyzer AS.