OVARRO Eureka5, User Manual

Page: 10 / 50

Eureka5 User Manual
CXD- 930 -UM- 044
Version: 1.3
Page 10 of 50
As the sound velocity can be calculated from knowledge of the pipe diameter and material, while the distance between the
sensors can be determined by careful measurement, the correlator can calculate and display the location of the leak as a
direct distance from its nearest
sensor. Alternatively, the correlator may be used to measure the actual velocity of sound in
the pipework being examined, so ensuring the highest possible accuracy in locating the leak.
2.2 Sensor Position
Correlator operation depends on having the le ak located between the two sensors. There are two situations where this is
not the case, and one sensor will have to be moved before an accurate correlation can be performed.
2.2.1
Leak Beyond Sensors
If the leak is located outside the length of pipe between the sensors, then the correlator will ignore the transit time from the
leak to the nearest sensor, as this transit time will be the same for both sensors. This will give the result that the leak w ill
appear to be located directly at the sensor nearest to the leak. (This is sometimes termed “out -of- bracket”.) This is an
indication that one sensor must be moved to locate the leak position accurately.
2.2.2
Leak on Connecting Pipe
If there is a leak on a pipe that connects to the pipe being sensed, then the noise will appear to spread from the point of
connection of the pipes, and so will appear as a leak at that point. It is then necessary to move one sensor to the connectin g
pipe (in other words, to place the leak between the sensors) to locate the leak accurately. A thorough knowledge of the
layout of the entire pipe network is required to ensure that the correlator is making measurements on the correct section of
pipe and that there is no possibility
of leaks on branch pipes causing false readings.