LOKAL 400 Operating Manual
Page 13
Up to 20 different pipe sections can be entered into the LOKAL 400 device. If a pipe consists of mixed
materials and/or features varying diameters, just enter the materials one by one into the table starting at
measurement box A (red). If you wish to delete any input, you can either press the button
“line“ [6]
or
select ” - - - “ as the pipe material.
When all pipe section materials have been entered correctly, pressing the PLAY button [7]
will
make the main mask of the correlation appear (see main illustration in Chapter 7.3
“Setting options for
correlation”). Pressing the door button [8] makes the system return to the main menu. If you press the
“Cancel” key (“
X
“), the system will go back to the window where you can choose between the automatic
and the manual measurement modes.
7.1.2. Starting the correlation
Once the
“Play” button has been pressed, the LOKAL 400 device will start automatically to adjust the
noise level amplification for the two channels (A [8 and 8.1] and B [12 and 12.1]) so that the noise level
optimal for the measurement process is available to the system. This is also indicated through the
adaptation of the amplification level [8.1 and 12.1] displayed at the lower edge of the correlation main
window.
He LOKAL 400 system will then carry out some test measurements with different filter settings [10] to
determine the optimal noise quality of the two signals [9] and [10] and of the coherence [10] respectively.
This is indicated by the number of average determinations [13] rising briefly, being canceled, and then
being counted up again with the next filter setting [10]. After a short while, the LOKAL 400 device will then
start on the proper measurement procedure and will determine the exact position of the source of the
noise. When the measurement has been completed, the number of average determinations stops
counting up [for the automatic mode, a total of 50 average determinations has been set ex works]. The
current measurement procedure can be interrupted anytime by tapping on the
“Stop” icon
(displayed in field [1] during the measurement process). The detected source of the noise, which is usually
the leakage spot, [see
Chapter 14 “Troubleshooting“] will be displayed in the upper image [6] as a symbol,
and the corresponding distance between the leakage spot and microphone A and microphone B
respectively will be indicated.
7.2 Manual measurement
If you wish to
carry out a measurement manually, please tap on the “Manual measurement” icon (as
shown above). A window will appear where you need to enter some data such as the pipe material, pipe
length, and pipe diameter. Then proceed as described in Chapter
7.1.1 “Entering pipe parameters“ for
the automatic measurement mode. When all pipe parameters have been entered correctly, tap on the
“Continue“ button
to get to the menu where the filters need to be set (see Chapter
7.3.1
“Filter settings”). The main image will show the coherence of the last measurement. Now please
set the high-pass filters and the low-pass filters in accordance with the frequency distribution. In addition,
the corresponding noises delivered through Channel A and Channel B can be listened to by activating
the headphones connection. So the operator can assess which filter setting provides the optimal noise
quality.
Click
on the “Continue“ button to reach the correlation main window (see illustration in Chapter 7.3 “Setting
options for corr
elation”). In contrast to the automatic mode, the measurement procedure will not start
automatically in the manual mode. The system requests the noise level amplification for Channel A [8]
and Channel B [12] to be adjusted in the main window. The same applies to all other signal entries.
