Method and apparatus for particle measurement employing optical imaging
A system and method for measuring small particles suspended in a fluid are disclosed. The system employs optical imaging using diffraction enlargement. A sample of small particles illuminated by a light source is imaged onto a pixel array of detector elements using an imaging optical system having a...
Saved in:
| Main Authors | , |
|---|---|
| Format | Patent |
| Language | English |
| Published |
27.05.2008
|
| Online Access | Get full text |
Cover
Loading…
| Summary: | A system and method for measuring small particles suspended in a fluid are disclosed. The system employs optical imaging using diffraction enlargement. A sample of small particles illuminated by a light source is imaged onto a pixel array of detector elements using an imaging optical system having a reduced magnification not sufficient for forming a large enough image of a smallest particle of interest. A low-aperture imaging optics with NA<0.05 is used to add diffraction enlargement to the image corresponding to at least 5 pixels to enable accurate measurement of images of smallest particles of interest, and to increase an optical sampling volume. Suitably programmed processor is used for determining at least a pixel count for each of the diffraction-enlarged images, and for generating a number, size or distribution of particles accounting for pre-determined diffraction enlargement of particle images of different sizes. The method enables analysis of large samples of small particles in one measurement. |
|---|