The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 03, 2001
Filed:
Oct. 15, 1998
David F. Nicoli, Goleta, CA (US);
Particle Sizing Systems, Inc., Santa Barbara, CA (US);
Abstract
An automatic dilution system and method provides optimal dilution factor DF for a sample suspension containing particles mixed with a diluent. A diluent flows into a mixing chamber, and the sample is injected into the chamber. A sensor, such as a single particle optical sensor (SPOS), measures the value of a particular characteristic, which characteristic R,(0) is the initial rate of increase of a quantity related to particle concentration. A CPU/Controller calculates from R,(0) the optimal value of DF, and develops a control signal which adjusts the flow of the sample to provide the optimal value of DF. In a first embodiment, all of the diluted sample passes through the sensor. In a second embodiment, only a portion of the sample is directed through the sensor to shorten the time to reach equilibrium. The time to reach equilibrium is further reduced in a third embodiment in which the mixing means is a static mixer, having relatively small volume, inserted in series with a diluent flow tube. The sample is injected into the flow tube upstream of the mixer. Larger dilution factors are obtainable in a fourth embodiment in which the sample is first prediluted in a mixing chamber and then further diluted in a second mixing chamber. A fifth embodiment also predilutes the sample, but to shorten the time to reach equilibrium, uses a static mixer for the second dilution stage. In all embodiments, the diluted fluid may be fed to one of two branches, one having an SPOS and the other having a sensor using the light scattering principle.