The Sludge Gun hand-held biosolids blanket level detector from Markland Specialty Engineering measures silt/biosolids interface levels in clarifiers, tanks and lagoons, and helps provide valuable biosolids level profiles. It allows users to monitor sludge bed depth for regulatory compliance and prevention of carryover, and to eliminate unnecessary pumping/dredging. It uses high-intensity infrared light to locate both the biosolids blanket and overlying cloudy layer, in concentrations ranging from light flocs to thick blankets. For example, Model 10-LP detects clear liquid surfaces; high-power Model 10-HP excels at finding the level of biosolids in murky lagoons. The unit is compact, weatherproof and convenient for boats/catwalks, with no calibration required. 855/873-7791; www.sludgecontrols.com.