The Suspended Solids Density Meter from Markland Specialty Engineering provides real-time knowledge of primary, secondary, return activated and backwash sludge, slurry and silt concentrations in pipes, tanks and clarifiers. It allows users to program underflow pumps to shut off before biosolids or feed solids density becomes too thin, and to optimize polymer dosing and equipment variables for enhanced dewatering. The nonintrusive inline pipe spool-piece sensor uses ultrasound to provide continuous percentage of suspended solids readings, unaffected by the color of particulates or fluid. It can offer early awareness of breaks in filtration material when used to measure filtrate concentrations. It sends out a pulse of sound and, when the solution is clear, receives a strong echo and reads zero. With particles present, the echo amplitude is reduced, and the meter measures the percentage of suspended solids. These readings enable calculation of mass flow rate. This process control instrument is simple to install, calibrate and clean. A throw-in-style probe is also available. 855/873-7791; www.sludgecontrols.com.