modifier for the current rate register. Note that the flow register is still zeroed and Reynolds
number compensated normally and these slope corrections are in addition to these
fundamentals.
Note
Kc is still active when this method is being used.
To install a Calibration table:
1. The
user
selects
a system variable that appears to correlate strongly with calibration shifts
observed.
2. A table of values is formed comprised of the values that this index could assume over the
range of system operation. Remember, the tables created do not extrapolate beyond their
end points, they "clip."
3. A calibration factor, a number usually close to 1.00, is entered as a positive and a negative
flowrate correction factor (termed PosFlow Corr and NegFlow Corr) for each of the desired
index points.
The table may contain up to 32 pairs of these slope correction factors. Note that the Kc factor,
unlike these slope correction factors, is entered as a signed percent change in rate, while these
factors are simply rate multipliers. As points are entered, the point editor will provide list access
to the already entered points plus access to the [New Point] menu cell, used to add a new
point. The table may be created in its entirety and then activated by selecting [Yes] in the [Table
Active] menu cell. The entire table may be cleared by selecting [Yes] in the [Clear Table] menu
cell.
Note
Careless use of the calibration tables can have a detrimental impact on the measurement
performance of the flowmeter.
Note
Take precautions before
enabling these calibration tables. Although it is unlikely that all three
tables would ever be employed in a real installation, three tables are offered for maximum
user flexibility. Since the tables can be disabled without being destroyed, 2 or 3 optimization
strategies may be tested by this means in order to determine which approach is most effective.
Appendix
A.5 Flowrate Calibration and Calibration Tables
FUP1010 IP67 Portable Flowmeter
Operating Instructions, 02/2010, A5E02951522A Revision 01
147
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