Siemens FUG1010 IP65 NEMA 4X, Operating Instructions Manual, Page: 110 / 271

Functions
7.4 Zero Flow Adjust Menu
FUG1010 IP65 NEMA 4X
Operating Instructions, 01/2013, A5E02951519-AC
109
Using ReversaMatic
If site conditions do not permit stopping the flow rate at the mounting location, and you do
not know the current flow rate, then you can use the ReversaMatic routine to establish the
zero flow level. You should perform the ReversaMatic procedure as quickly as possible to
ensure that the flow rate remains constant throughout the procedure.
To invoke ReversaMatic:
1.
To access the [Zero Flow Adjust] option list press <Right Arrow>.
2. Move the cursor to [ReversaMatic]. Press <ENTER> to invoke the routine.
3. The flow meter begins to measure the positive flow rate. "Positive" flow refers to flow
moving from upstream sensor location to the downstream sensor location. Note top
prompt line shows: Reversamatic Action
4. Upon completion, the flow meter beeps and the display screen shows: Reverse Sensors /
Press <ENTER>
5. Now remove then remount the upstream and downstream sensors in their reversed
positions. Mount the Up sensor (without removing its cable) in the Down sensor/cable
location. Mount Down sensor with its cable in the Up sensor/cable location. When
remounting the sensors, couple them to the pipe properly. Press <ENTER> (after re-
installing the sensor).
6. The flow meter measures the negative flow rate briefly, then beeps and repeats the
prompt: Reverse Sensors / Press <ENTER>
7. Now remount the sensors for normal operation (in their original orientation). When
remounting sensors, couple them to the pipe properly. Press <ENTER> (after re-installing
the sensors).
This completes the ReversaMatic procedure. The system’s zero accuracy will be very close
to that obtainable using the Actual Zero method, providing flow remained constant during this
procedure.
NOTICE
Preventing Flow Mis-Registration
A caution on the use of upper and lower flow limits (used to prevent flow mis-registration)
prior to using the Reversal Zero technique (ReversaMatic): If the negative flow rate that the
flow meter reads in the step during which the sensors 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.