ADS Environmental Services Eureka Digital QR 775020 A0 - Manual (Page 14)

ADS Eureka Digital System User Manual
10
Sensor Position
Correlator operation relies on the location of the leak existing between the
two sensors. However, two contexts can prevent this from occurring. The
solution requires moving one sensor before a successful correlation can be
performed.
Leak Beyond the Sensors
If the leak is located beyond the length of pipe between the sensors, the
correlator will ignore the transit time from the leak to the nearest sensor
because the transit time will be the same for both sensors. This will give
the impression that the leak exists directly at the location of the sensor
closest to the leak (occasionally referred to as out-of-bracket). This
requires that one sensor be moved to locate the leak position accurately.
D
Sensor A Sensor B
Leak
Leak on Connecting Pipe
If the leak is occurring on a pipe that connects to the pipe being measured,
the noise will appear to spread from the connection point and, therefore,
indicate that point as the location of the leak. This requires moving one
sensor to the connecting pipe, ensuring the leak falls between the sensors,
to accurately locate the leak. A thorough knowledge of the entire pipe
network layout is essential to ensuring that the correlator is taking
measurements on the correct section of pipe and that no possibility exists
for leaks on branch pipes, causing false readings.
D1
D2
True position
of leak
Sensor A
Sensor B
Sensor C
Leak position
indicated with
sensors at A and B