40
│ 3 Using the system
3. Select the area you want to hide.
a)
Tap the correlation curve to set the first limit.
b) Tap the correlation curve again to set the second limit.
The hidden area is displayed in orange.
4. Tap
Back
. The settings are applied. The receiver will switch to
the
Filter
menu. The correlation curve shows the hidden area.
Hidden peaks can be shown again at any time.
●
Tap the
Show peak
button in the
Correlation
menu. The se-
lected area is deleted. The selected peak is visible again.
3.6.3
Sound velocity measurement
The sound velocity depends to a large degree on the pipe data
(length, diameter, material). The receiver has default values for
the sound velocity which are used to calculate the leak position.
In practice, there may be deviations from the known or assumed
pipe data on a measuring section. These deviations can have
a significant effect on the accuracy of the measurement. This
applies in particular to leaks that are not located in the middle of
the measuring section. A sound velocity measurement is recom-
mended in such cases.
.
Fig. 28:
Sound velocity
menu
Top:
Correlation curve
Below (from left):
Start measurement, Reset, Outside 1
,
Between the transmitters
,
Outside 2
buttons
Bottom:
Measured sound velocity, number of calculations
