Markland Specialty Engineering: The handheld Sludge Gun® can be used to easily find sludge levels in lamellas and clarifiers used to clean water in the paint industry. These processes are the first steps in protecting the environment and meeting regulations. The design is portable and weatherproof. Sensitivity is adjustable. An audible tone that varies in volume and pitch indicates the sludge layer.pci0312-PR-Markland_100.jpg