User's Manual

19
Regression Analysis
Regression Analysis provides an additional way of pinpointing leak positions by using a set of
correlation results, rather than an individual correlation result. This also provides a way of
measuring an accurate velocity.
The time delay / distance relationship of the correlation is linear, as the distance between a
sensor and the leak noise increases, the time taken for the sound to reach the sensor
increases proportionally with the distance. For example, if you move the sensor twice as far
away, the sound will take twice as long to reach it. It is this linear relationship that makes it
possible to predict values for varying time delays / distances when using a set of correlation
results.
Before the regression analysis feature can be used, correlation’s must have been saved on
the control unit. For an accurate result it is recommended to save three correlation’s, but
obeying the following two rules :-
- One of the sensors must remain static during the collection of data. Which of the sensors
does not matter.
- The pipe material and diameter must be constant for each of the correlation results. This
is validated by the control unit.
Red
Blue Position
1
Blue Position
2
Blue Position
3
Correlation Result 1
Correlation Result 2
Correlation Result 3
Press 3 (Regression Analysis) After correlation results have been saved. Press 1 to Add a
result, the file screen will appear, select the first correlation result saved.
The control unit will then ask for the “Static Out Station” colour. The control unit will store the
material and diameter of the first correlation result and compare with the next results to be
added, this ensures these details remain constant.
A regression analysis graph will appear showing time delay and distance. A cross will appear
on the graph plotting the first correlation result.