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82 UMG70XV3-4EN 12.01.2009
10 Basic Measurement
If
OTHER MATERIAL
is selected, the sound velocity has to be entered.
For the sound velocity of some materials see annex C, Table C.1.
10.1.5 Pipe Roughness
The flow profile of the medium is influenced by the roughness of the inner pipe wall. The
roughness will be used for the calculation of the profile correction factor. As, in most cas-
es, the pipe roughness can not be exactly determined, it has to be estimated.
For the roughness of some materials see annex C, Table C.2. The values are based on
experience and measurements.
10.2 Input of the Medium Parameters
The media to be displayed in the scroll list can be selected (see chapter 14.5).
For the programmed parameters of common media see annex C, Table C.3.
If a medium is selected from the scroll list, the menu item for the input of the medium
temperature is displayed directly (see section 10.2.5).
If
OTHER MEDIUM
is selected or no data set for the selected medium is stored in the flow-
meter (e.g. natural gas, as the parameters depend on the composition of the natural
gas), the medium parameters have to be entered first:
Enter the sound velocity of the lining material. Press
ENTER.
Enter the thickness of the liner. Press ENTER.
Note!
The inner pipe diameter (= outer pipe diameter - 2x pipe wall thick-
ness - 2x liner thickness) will be calculated internally. If the value is
not within the inner pipe diameter range of the connected transduc-
ers, an error message will be displayed.
It is possible to change the lower limit of the inner pipe diameter for a
given transducer type (see section 12.8).
Enter the roughness of the selected pipe or liner materi-
al.
Change the value according to the condition of the inner
pipe wall. Press ENTER.
Select the medium from the scroll list.
If the medium is not in the scroll list, select
OTHER MA-
TERIAL
. Press ENTER.
c-Material
3200.0 m/s
Liner Thickness
3.0 mm
Roughness
0.4 mm
Medium

natural gas