Siemens SITRANS FUS1020, Manual, Page: 193 / 251

7-4
1020NFM-1D Section 7
Vs m/s
This menu cell shows the current sonic velocity in meters per second (m/s). If you move the cursor to
this menu cell you will note that it switches from the usual arrow (
Ä
) to a question mark (?). This
indicates that you can increase the reading by pressing the [+] key for coarse adjustment or the [1] key
for fine adjustment; or reduce the reading by pressing the [-] for coarse adjustment or the [2] key for fine
adjustment. (When using the magnetic wand, touch the Enter sensor to increase the reading; touch
the <Right Arrow> sensor to decrease the reading.) The pipe diameter and transmission frequency
determines the effective increase or decrease per key press. Sonic velocity (Vs) adjustment is a
diagnostic tool intended for our technicians or experienced users only. Improper use will affect the
meter accuracy.
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 Controlotron customer service engineer may ask you to
edit these settings during a support session. In such a case, a <Right Arrow> at 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 lower 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.
Moreover, 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.
Flow GAL/MIN 120.00
Total GAL 5645.820
Vs m/s 1274.33
Signal mV 44
Valc % 57
Vaer % 13
Alarm Status ------M--
AnCal GAL/MIN > 120.000
HiFlow GAL/MIN 1577.9
LoFlow GAL/MIN -1577.9
Siemens 2 Channel [1] Channel 1
Flow Rate Simulation Control
Flow Data
The M status is
asserted due to the
method used to
simulate flow data.
Note that the [Flow]
menu cell immediately
reflects the AnCal entry.
Over time, the Total
display will also
increase.