Overflow monitor

Pulsar's SludgeFinder sludge level monitor uses a self-cleaning acoustic sensor that sits under the liquid surface of a clarifier or sludge tank. An acoustic signal is bounced off the bottom of the tank and modulations in the returning signal are interpreted to provide a profile of the sludge in the tank.

Water companies can use this information to optimise chemical dosage and to save employees from having to make time-consuming and potentially unhygienic manual measurements and calculations. Multiple vessels are not a problem as each SludgeFinder controller can handle up to four transducers sited up to 1000 m from the control unit.

To program SludgeFinder, the operator enters the tank depth and zero adjust parameters via a menu-driven interface and the SludgeFinder automatically sets the system gain and tracks to the blanket interface.

SludgeFinder is designed to be maintenance free. The SludgeFinder transducer is a single beam ultrasonic unit immersed in the liquid. A replaceable rotary PVC wiper blade is in continuous contact with the transducer face, ensuring that the transducer face remains clean. The transducer has a measurement range of 0.3 to 50 m. Accuracy is approximately ±0.03 m. A tight 6° beam angle and sophisticated echo processing algorithms make sure that SludgeFinder deals with difficult tanks and rotating equipment with ease.

SludgeFinder features 4-20 mA isolated outputs for each channel, with multi-drop RS485 connection, also isolated up to 1500 VAC. Four control relays are included (10 A rated), independently assignable to any channel. Change-over loss of echo (LOE) relay alarm is also included.