Hiflow And Loflow; Ancal - Siemens SITRANS F Operating Instructions Manual

Section 2

HiFlow and LoFlow

The HiFlow and LoFlow menu cells allow you to enter maximum and minimum expected flow rates
based on current operating conditions. Under normal circumstances, you should never need to change
these settings. It is possible however, that a Siemens customer service engineer may ask you to edit
these settings during a support session. In such a case, pressing the <Right Arrow> the menu cell
enables numeric entry.
Important Note: A caution on the use of upper and lower flow limits (used to prevent flow mis-registra-
tion) prior to using the Reversal Zero technique (Reversamatic): If the negative flow rate that the meter
reads in the step during which the transducers are reversed is more negative than the over flow limit,
the meter will re-register positive and the Reversal Zero cycle will thus be corrupted.
Therefore, postpone the installation of upper and lower flow limits until the reversal zero procedure is
executed successfully. For pipes that combine large diameters with very high flow velocities, it may be
necessary to move the upper and lower flow limits out of the way until the reversal zero is completed.
Moveover, pipes of this size frequently have excellent intrinsic zero performance and may not even
need zeroing.

AnCal

This menu cell allows you to enter an artificial flow rate in current rate units that will drive the meter's
analog outputs, totalizer output and the screen shown below. You can use AnCal to check the analog
outputs or as a reference source for calibrating external devices such as remote display screens or
chart recorders and RTU's. To test the Totalizer function, leave AnCal active for enough time for an
accumulation to appear on the screen below. Moving the cursor from the menu cell cancels the AnCal
function.
The M status is
asserted due to the
method used to
simulate flow data.
To activate AnCal:
Move the cursor to the [AnCal] menu cell by pressing
Press to enable numeric entry. Note that an equal sign (=) appears before the number.
Type the desired flow rate using current rate units (e.g., 120.00 GPM). Note that the [Flow] menu
cell now reflects the artificial rate.
Move the cursor away from the menu cell by pressing
Siemens Dual Path
Flow Rate Simulation Control
Flow GAL/MIN
Flow Vel F/S
Total GAL
Vs m/s
Signal mV
Valc %
Vaer %
Alarm Status
AnCal GAL/MIN
HiFlow GAL/MIN
LoFlow GAL/MIN
Flow Data
2-60
SITE1
120.00
4.23
5645.820
1274.33
44
57
13
------M--
> 120.000
1577.9
-1577.9
.
to turn AnCal off.
1010PFM-3G
Note that the [Flow]
menu cell immediately
reflects the AnCal entry.
Over time, the Total
display will also
increase.