Siemens SITRANS F Instruction Manual page 79

Section 2
Immediately after you press <ENT>, the computer starts an internal process called an Initial Makeup. The
current Initial Makeup activity, for example: Drive 14 m 10 [——] appears at the top of Display Screen.
During the Initial Makeup, the flow computer verifies your site data, records the sonic characteristics of
the pipe and liquid and then adjusts internal parameters to optimize flow measurement. Please remain
patient. This process can take several seconds or several minutes to complete. There is no relationship
between the length of an Initial Makeup and the meter's subsequent performance. An Initial Make-up for
larger pipes (and more demanding application conditions) simply takes a little longer. Upon sucessful
completion of the initial makeup, the 1010 will show you a pop-up window with the measured Vs as
shown below.
This means that the flow computer was able to complete the Initial Makeup and is now actively measur-
ing flow. This pop-up window allows you to "fine-tune" the Measured Vs by pressing the <Right Arrow> to
activate numeric entry. You can then use the numeric keys to type a different value. However, only edit
the Measured Vs when you are certain of your liquids actual sonic velocity. If, however, there is a large
discrepancy between the "measured" Vs and the "actual" Vs, then consider that an accurate Vs mea-
surement depends on certain parameters that the flow computer cannot sense directly (e.g., pipe di-
mensions or transducer placement). In other words, entering incorrect pipe parameters or not using the
recommended spacing could result in an erroneous Vs measurement.
The meter is now ready to report flow. Press the <MENU> key to display flow.
In cases where the actual Vs differs noticeably from the estimated Vs, the computer may issue a re-
space command. This requires that you re-space the Number Index transducer at the new Number
Index, then press <ENT> again. Repeat the initial makeup process. You can override a re-space com-
mand by simply keying the [Down Arrow]. However, after the meter 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 inaccu-
racy. 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:
Pressing
If you decide to edit the Measured Vs:
To activate numeric entry press
Use the numeric keys to type the new Vs value (in meters-per-second).
To store the corrected Vs press
The flow computer may recommend a new Number Index and prompt you to press
Remount the transducer at the new Number Index.
Measured Vs m/s
or moves the cursor to the [Empty Pipe Set] menu cell.
ENT
1470
2-25
1010ENFM-3B
.
ENT