The portable Sludge Gun® is designed to quickly locate the sludge bed in clarifier and settling tanks. A probe is lowered into the liquid and high intensity bursts of infrared light travel from an LED across the probe gap to a photo transistor. A solid-state circuit then differentiates between liquid and sludge in the gap. The circuit is designed to ignore solids suspended in the liquid and to continue down – looking for the real sludge bed.  A loud variable pitch horn on the butt of the gun howls as the probe nears the sludge, and the pitch and volume of the sound increases as the probe passes through the “cloud” above the sludge and into the sludge bed. By carefully listening to the note, the operator can ignore the solids floating above the sludge and can determine the location of the true sludge level. 
 

Features
• Simple one-hand operation – even when wearing gloves
• Self-storing cable spool prevents tangles  
• Useable at night – no dials to read
• Weatherproof case – useable in the rain
• Spring-loaded trigger turns off gun – users cannot leave it on and drain the battery
• No bulbs to change – 100% solid state
• Over one year battery life in normal service
• Thumb-adjustable sensitivity control that is easy to set
• Uses standard Pencell batteries
• Single plug-in style printed circuit board
• Weight 2 kg (4 1/4 lbs)