What are they?
A leak noise correlator can be used to mathematically determine where a leak is located between two leak sensors, and can quickly and precisely pinpoint a leak. Leak sound will travel down the pipe wall away from the leak. Engineers have determined the normal speed of sound through different sizes and materials of pipe. These speeds are programmed into the software so that a mathematical formula is used to determine the time difference leak noise takes to reach two or more sensors from the point of the leak. Three things are generally needed to do the calculations which include the pipe material, pipe diameter, and the footage of pipe between the sensors. With these inputs, the software can accurately calculate the distance of the leak from each sensor.
Leak correlators can give very accurate leak locations to pinpoint leaks for repair, and can often even find multiple leaks in the distance between the sensors at one time even though a person may only hear the louder one with a simpler leak locator. A best practice is to verify the correlation by verifying the location with a ground microphone in case of errors in the data entered to do the leak noise correlation.