43
11.5
Cut-off Flow
The cut-off flow is a lower limit for the flow velocity. All measured flow velocities that are lower than the limit and their de-
rived values are set to zero.
The cut-off flow can depend on the flow direction or not. The cut-off flow is set in
Special Funct.\SYSTEM set-
tings\Measuring\Cut-off Flow
.
Select
sign
to define a cut-off flow in dependence on the flow direction. Two independent
limits are set for the positive and negative flow directions.
Select
absolut
to define a cut-off flow independently of the flow direction. A limit is set for
the absolute value of the flow velocity.
Press ENTER.
Select
factory
to use the default limit of 2.5 cm/s (0.025 m/s) for the cut-off flow.
Select
user
to enter the cut-off flow.
Press ENTER.
If
Cut-off Flow\sign
and
user
are selected, two values will have to be entered:
Enter the cut-off flow. Press ENTER.
All positive values of the flow velocity that are lower than this limit will be set to zero.
Enter the cut-off flow. Press ENTER.
All negative values of the flow velocity greater than this limit will be set to zero.
If
Cut-off Flow\absolut
and
user
is selected, only one value will have to be entered:
Enter the cut-off flow. Press ENTER.
The absolute values of all flow velocity values that are lower than this limit will be set to zero.
11.6
Uncorrected Flow Velocity
For special applications, the uncorrected flow velocity might be of interest.
The profile correction for the flow velocity is activated in Special Funct.
\SYSTEM settings\Measuring\Flow Veloc-
ity
.
Select
normal
to display and transmit the flow velocity with profile correction.
Select
uncorr.
to display the flow velocity without profile correction. Press ENTER.
If
uncorr.
is selected, it has to be confirmed each time the program branch
Measuring
is selected if the profile correction is to be used.
If
no
is selected, the profile correction will be switched off.
All physical quantities will be calculated with the uncorrected flow velocity.
During the measurement, the designation of the physical quantity will be displayed in capi-
tal letters to indicate that the value is uncorrected.
Press ENTER.
If
yes
is selected, the uncorrected flow velocity will only be used if the flow velocity is se-
lected as the physical quantity in the program branch
Output Options
.
All other physical quantities (volumetric flow rate, mass flow, rate etc.) will be determined
with the corrected flow velocity.
During the measurement, the designation of the physical quantity will be displayed in capi-
tal letters to indicate that the value is uncorrected.
Press ENTER.
In both cases, the corrected flow velocity can also be displayed.
Press key to scroll until the flow velocity is displayed. The uncorrected flow velocity is
marked with
U
.
Uncorrected flow velocities transmitted to a PC are marked with
uncorr.
Cut-off Flow
absolut >SIGN<
Cut-off Flow
factory >USER<
+Cut-off Flow
2.5 cm/s
-Cut-off Flow
-2.5
cm/s
Cut-off Flow
2.5 cm/s
Flow Velocity
>NORMAL< uncorr.
PROFILE CORR.
>NO<
yes
FLOW VELOCITY
2.60
m/s
PROFILE CORR.
NO
>YES<
Flow Velocity
*U 54.5
m/s
