Patent ID: 11946852
Assignee: PARTICLE MEASURING SYSTEMS, INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A system for detecting particles in a fluid, the system comprising:
a flow cell for flowing a fluid containing particles along a flow direction through a beam of electromagnetic radiation,
an optical source in optical communication with the flow cell for providing the beam of electromagnetic radiation;
a focusing system in optical communication with the optical source for focusing the beam of electromagnetic radiation to generate an area of high radiation density within the flow cell;
wherein the focusing system comprises a diffractive optical element configured to shape the beam into a top hat beam profile; and

an on-axis optical collection system for collecting and directing at least a portion of the electromagnetic radiation onto a forward looking photodetector;
wherein the forward looking photodetector comprises at least a first detector element and a second detector element, and wherein the first detector element is configured to produce a first electric signal and the second detector element is configured to produce a second electric signal, the system being configured to characterize the number and/or size of particles detected based on a differential signal derived from the first and second electric signals.