
Flow Calibration
FLOWSIC600 · Technical Information · 8010125 V 4.0 · © SICK AG
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3.2.3
Adjustment methods
The following adjustment methods are implemented in the FLOWSIC600 firmware and
supported by the "Meter calibration" wizard in MEPAFLOW600 CBM:
●
Adjustment with constant factor (
)
●
Adjustment using a polynomial correction (
●
Adjustment with piece wise linear error interpolation (
)
3.2.3.1
Adjustment with a constant factor
In general the "standard" calibration is carried out by calculating one adjust factor for the
whole flow range of the meter.
The Adjust factor is calculated from the weighted mean error (WME) or the flow weighted
mean error (FWME) of the flow rates Q
i
.
The WME is calculated by the test labs according to the equation:
For Q
i
> 0.9 Q
max
a weighted factor of 0.4 should be used instead of 1 (OIML 137-1).
If the meter is calibrated for bidirectional use, a second weighted mean error (WME) is
determined using the values established separately for each direction of flow.
The new adjust factor is calculated as follows:
NOTICE:
Type approval
The method "correction with piece wise linear error interpolation" is not
approved in every country for use in custody transfer applications. Cross-check
with the type approval of the FLOWSIC600 for your country.
See
»Calculating the volumetric flow rate« (pg. 24)
Q
i
:
Tested flow rate
Q
max
:
Tested maximum flow rate
E
i
:
Mean error in % established at the tested flow rate
The actual weighting of the error at higher flow rates may be different based on
recommendations, or national regulations and/or type approvals.
WME =
i = 1
n
k
i
•
E
i
i = 1
n
k
i
where k
i
=
Q
i
Q
max
AF =
1
1 +
WME
100