Optek-Danulat Inc.’s TF16-N dual-channel scattered light turbidity sensor completes in-line real-time processing in sanitary, high-pressure, high-temperature and explosion-prone situations. A constant near-infrared light beam from 730 to 970 nm penetrates the process medium. Eight hermetically sealed silicon photodiodes at an 11° angle detect light scattered from trace-suspended solids, undissolved liquids and gas bubbles. Simultaneously, a reference photodiode detects unscattered light. The sensor can be calibrated to measure minute particle sizes and concentrations. To resist abrasion and corrosive media, the sensor body is made of 316L stainless steel, while the optical window is made of a single-crystal sapphire.