Correlation method of detection of water leakage in pipelines and their localization is based on the measurement of the Vibro signal generated by the leakage, with the help of two sensors-accelerometers, which have a magnetic base and are installed Directly on the pipeline or shutoff valves (valves, fire hydrants, etc.). If two sensors are installed from both sides of the alleged leakage location and measured by a correlation detector, a reciprocal correlation function can be computed, and a temporary delay of leakage noise to one and to the second sensor is calculated. Knowing the speed of noise propagation in this pipeline (its value depends on the material of the pipe, its diameter and wall thickness), it is possible to calculate the distance to the leakage (place of the source of noise) from each of the sensors.
Leakage in the pipeline generates noise (acoustic and vibrating signals), which is transmitted over long distances, both on the tube and in the ground, located close to the place of leakage. The characteristics of this noise depend primarily on the hydraulic pressure, the material and the diameter of the piping, the thickness of the pipe walls, the size and shape of the leakage.
The term "noise" in this case means a combination of leakage signals and ambient noise from different sources. Acoustic Devices (hydrophones) and mechanical Vibration measurement devices (accelerometers) are the most common converters used to measure the level of this noise. The signals received from these converters are analyzed by correlation.
The principle of action of correlation detectors is based on the rule of mutual correlation of leakage signals, which are obtained from transducers (sensors) installed in two known access points (for example, on fire hydrants) on both sides of the leakage . In case of leakage detection, a clear peak is formed in the corresponding area of the histogram.
Fisher XLT-30 a Acoustic leak detector
Fisher XLT-30 Acoustic leak detector -used to detect fluid leaks in pipes and vessels. Give your console with a wide range of functions and special amplifier allows to detect leaks in great depths.