Siemens SITRANS FUH1010PVDX, Operating Instructions Manual, Page: 127 / 308

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CQO:1010PVXFM-3 Section 5
5.4.4 REVIEWING THE SPACING METHOD
The flow computer analyzes your transducer selection, mounting mode and pipe size to determine the
best way to install your transducers. It will recommend the use of either a mounting track, a spacer bar,
or independent mounting. The flow computer will list the part number of a mounting track or spacer bar.
If it decides upon independent mounting, it will report the distance required between the two transduc-
ers. In this case, you have to make sure that when you mount the transducers, the space between them
equals the length specified in the Ltn menu cell.
5.4.5 HOW TO USE THE SPACING OFFSET
After you select the mounting method, the flow computer checks your entries for pipe size, transducer
type etc. and then recommends a spacing offset. This is the first step in establishing the correct distance
between the transducers. Spacer bars and mounting tracks
utilize number indices (labels) to simplify
transducer placement. One transducer is located at the Reference position, while the other one is lo-
cated at the Number Index position. The Number Index cannot be directly edited. However, the Spacing
Offset can be changed via its option list. Changing the Spacing Offset will alter the reported Number
Index. Maximum spacing offset provides moderately greater signal levels but, in some cases, slightly
decreased zero flow stability.
If the flow display computer reports “Use Ltn,” you have to measure the distance between the upstream
and downstream transducers. The flow computer issues the actual distance between the transducers in
inches or millimeters (See paragraph 5.4.7 Ltn Menu Cell). Note that, even though using Ltn does not call
for the physical use of the Number Index, you can still change the Spacing Offset to influence the strength
of the transmit signal.
The FUH1010PVX uses a pair of precisely matched transducers. Therefore, you can select either one for
the Reference position. You must connect the Up transducer cable to the transducer mounted on the
upstream side of the mounting track. This lets the meter display the flow direction correctly.
It is important that you note each transducer’s serial number and its Index position during the original
installation because to reinstall the flowmeter successfully, you must remount each transducer in its
original position. Transducer pairs have matching serial numbers except for the appended letters “A” and
“B.” This helps you to identify each transducer.
To select a different Spacing Offset
To access to [Spacing Offset] option list press
To move the cursor to the desired offset press
To store selection press
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