Optical density monitor and comparator systems and methods

A method for determining the absorption coefficient and/or the optical density of a fluid and/or organic/inorganic particles disposed in the fluid, comprising:

• providing an integrating flow cell configured to contain a fluid sample within substantially an entire interior portion thereof;
• providing one or more point radiation sources disposed about an interior periphery of the integrating flow cell, wherein the one or more point radiation sources are operable for delivering radiation of a predetermined wavelength to the fluid sample;
• and
• providing one or more radiation detectors operable for detecting radiation within the interior portion of the integrating flow cell;
• wherein the integrating flow cell comprises an integrating sphere having an interior surface operable for reflecting the radiation delivered to the fluid sample by the one or more point radiation sources such that a radiation intensity is uniform throughout the interior portion of the flow cell;
• and
• wherein a path length of the radiation delivered to the fluid sample and reflected is maximized by the fluid sample occupying substantially the entire interior portion of the integrating flow cell.