Method and apparatus for measuring particle size at low concentration

摘要

PCT No. PCT/NL96/00388 Sec. 371 Date Sep. 14, 1998 Sec. 102(e) Date Sep. 14, 1998 PCT Filed Oct. 4, 1996 PCT Pub. No. WO97/13139 PCT Pub. Date Apr. 10, 1997Described is an improved method for measuring the particle size of ultrasmall particles (111) which are suspended in a fluid. Laser light (121) is scattered by the particles, and the scattered light (122) is received by a light detector (131) which provides an electrical measuring signal (Sm) which is representative of the intensity of the scattered light (122). According to the present invention, signal components with a relatively low characteristic frequency are removed from the electrical measuring signal (Sm), and the particle size is calculated on the basis of the thus corrected measuring signal (Sc), so that also at a very low concentration of the particles (111) reliable results are achieved.