Siemens SITRANS FUS1020, Manual, Page: 146 / 251

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1020NFM-1D Section 6
In cases where the actual Vs differs noticeably from the estimated Vs, the flow computer may issue a
re-space command. This requires that you re-space the Number Index transducer at the new Number
Index, then press <ENTER> again. Repeat the initial makeup process. You can override a re-space
command by simply keying the [Down Arrow]. However, after the flowmeter begins operating, you
must confirm that the sonic velocity (Vs) of the liquid falls between the [Vs max] and [Vs min] items in
[Diagnostic Data / Site Setup Data].
Therefore, only consider editing the measured Vs after you remove all the primary causes for an in-
accuracy. Check your pipe dimensions and pipe material entries. Re-check the transducer spacing
and part numbers. Large Vs discrepancies are almost always due to erroneous pipe data or incorrect
transducer placement.
To accept the Measured Vs:
Press the <Left Arrow> or <Down Arrow> moves the cursor to the [Empty Pipe Set] menu cell.
If you decide to edit the Measured Vs:
To activate numeric entry press the <Right Arrow>.
Use PC numeric keys or KeyPad to type the new Vs value (in meters-per-second).
To store the corrected Vs press <ENTER>.
The flow computer may recommend a new Number Index and prompt you to press <ENTER>.
Remount the transducer at the new Number Index.
To repeat the Initial Makeup process press <ENTER>.
After the flow computer completes its Initial Makeup command, the [Install Complete?] option list changes
to:
If you want to redo the Initial Makeup, move cursor to New Makeup, then press <ENTER>. This resets
the option list. You can now repeat the install routine described previously.
6.4.9 THE EMPTY PIPE SET MENU
CAUTION: Only access the [Empty Pipe Set] menu when using the Actual MTY command.
The flow computer performs the MTYmatic routine automatically during its Initial Makeup to establish a
standard setting for the Empty Pipe alarm. The [Empty Pipe Set] option list allows you to re-invoke
MTYmatic, use an Actual MTY routine (if application conditions allow you to empty and refill the pipe) or
use the Set Empty routine to set the empty pipe threshold by direct numeric entry.
How to Use the Actual MTY Command
If application conditions allow you to empty and refill the pipe, then you should perform the Actual Empty
procedure. This is the recommended way to define the empty pipe threshold.
Install Complete? Yes
New Makeup