Technology Description

The innovative Gutermann Star® ZoneScan sensor is the only remotely correlated acoustic leak detection system available for use with AMI. These sensors can be installed on existing water distribution system meters and integrated within an AMI network for the continuous monitoring of leaks. Data can be transmitted through a fixed communication network used by the AMI. To augment the AMI system, acoustic sensors are installed at convenient locations permanently or temporarily to listen for water leaks. These noise loggers are active at night when background noise is lowest and pressure is highest to monitor for a predetermined leak signature. If no leak is present, data are transmitted to indicate normal background conditions. When a “leak-like” noise is detected, the unit transmits a radio signal to indicate a possible leak condition. Most acoustic sensors are designed to indicate the nearby occurrence of a “leak-like” noise, but do not pinpoint the location of the leak via cross-correlation. The use of cross-correlation may also help to minimize “false positives” caused by background noises such as traffic and HVAC systems.

The need to augment the ZoneScan sensors will be investigated. If needed, the augmentation will include the use of an innovative acoustic technology, Echologics LeakFinderRT™, which can also be used to detect leaks while assessing the structural condition of the pipe wall, which the Gutermann system cannot do. The leak detection uses cross-correlation methodology. To assess the structural condition, the technology works by measuring how quickly acoustic signals are transmitted within the water column, as well as along the pipe wall. The sensor type depends on the water system with hydrophones sensing leak-induced sound in the water column and accelerometers sensing leak-induced vibration in the pipe wall. The hydrophone sensors are installed through fire hydrants, while the accelerometers are placed in contact with the pipe wall through potholes. A personal computer calculates the cross-correlation function of the two leak signals to determine the time lag between the two sensors.