Zeromatic; Using Actual Zero; Using Reversamatic - Siemens SITRANS F Operating Instructions Manual

Section 2
ZeroMatic (not present in MultiPulse operation)
When ZeroMatic is invoked the flowmeter first performs the same analysis as described above in the
AutoZero routine. However, after this analysis is complete the flowmeter continues to interrogate the
pipe wall signal and update the zero offset value under normal operation, such that the flowmeter
dynamically compensates for changing conditions which would normally result in zero drift. ZeroMatic
will only operate with the transducers mounted in the Reflect Mode configuration and is recommended
for applications which experience large temperature extremes.
NOTE: Invoking ZeroMatic will clear any existing "fixed" or memorized zero offset. If any zero
offset remains after flow is stopped, an Actual Zero can be performed without inter-
rupting ZeroMatic operation. To disable ZeroMatic, invoke it again, but then press <Left
Arrow> to abort the installation.
NOTE: The ZeroClr command only resets the memorized zero offset registers not those set
when the AutoZero routine is invoked.

Using Actual Zero

NOTE: Flow must be stopped with the line blocked (if possible) before invoking this function.
To invoke Actual Zero:
Access the [Zero Flow Adjust] option list by pressing
ENT
Press . A pop-up window prompts you to set the current flow rate (in selected
rate units) to equal zero (0.000).
NOTE: If a flow offset is desired (i.e., to test analog outputs) then press <Right Arrow> to
enable numeric entry.
ENT
Press to start the Actual Zero process.
When you send the command, the flow computer analyzes the current flow rate for up to sixty sec-
onds, integrating (averaging) the data for the best zero correlation. During this time, the menu prompt
at the top of the display screen shows a timer that counts from zero to sixty. You can allow zero
averaging for the entire period, or cancel the process at any time by pressing the <ENT> key. This
controls the amount of data the meter averages to obtain a zero level.

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 re-
mains constant throughout the procedure.
To invoke ReversaMatic:
To access the [Zero Flow Adjust] option list press
Move the cursor to [ReversaMatic]. Press
ENT
to invoke the routine.
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