Patent ID: 8582100

Claim:
An optical fluid monitoring system for imaging particles in at least one conduit carrying a flowing fluid, comprising: a plurality of optical sensors positioned along the at least one conduit, each sensor positioned to transmit laser optical energy into a transparent viewing window in a fluid flow conduit in a direction across the direction of flow, each sensor having an optical imaging system for receiving the optical energy after it has passed through the fluid flow and for imaging particles in the fluid flow; wherein a first one of the plurality of sensors is configured to image a range of larger size particles and a second one of the plurality of sensors is configured to image a range of smaller size particles, and for each sensor, the conduit thickness at that sensor is such that the particles in the size range to be imaged are in the optical near field of the imaging system, and wherein the first sensor conduit has a conduit thickness that is larger than the second sensor conduit.