Siemens SITRANS F - Multipoint Calibration

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1010PFM-3GSection 2
MultiPoint Calibration
MultiPoint calibration serves applications that require a non-linear meter calibration. You can enter cor-
rection factors for up to ten significant points over the entire measurement range. This is accom-
plished by:
§ Selecting up to 10 separate calibration points by entering a raw (uncalibrated) flow rate.
§ Entering a negative or positive correction for each calibration point that you select.
Like the Kc slope correction described in the previous section, you locate critical flow rate points by
comparing flow total data taken simultaneously from the 1010P and a reference meter whose accu-
racy meets the required standard. Again, it is important to note that you must allow both meters to
accumulate flow total data for a period long enough to average out any differences due to flow fluctua-
tion between the meter locations.
Compare the two flow total readings to identify up to ten separate points (termed raw flow rates) where
there are significant deviations between System 1010P and the reference meter. Calculate correction
factors (either negative or positive percentages) for up to ten points along the flow range. For example,
entering [-0.1] for point 1 produces a negative 0.1% change in the meter output whenever the system
measures the raw flow rate specified for point 1, etc. The valid range for each percent correction is
from -50% to +50%. If you enter a value outside of this range, the flow computer will set the calibration
factor to the nearest limit.
This function is used to match System 1010P’s output with the reference meter’s response curve.
Selected calibration points must increase in magnitude from point 1 to point 10 (or the last point that
you wish to calibrate).
NOTE: You must enter the raw flow rates in ascending order.
To perform a MultiPoint Calibration:
To access the [Calibrate Flow Rate] option list press
Move the cursor up to [MultiPoint], then press
This selects the MultiPoint calibration screen, which shows:
ENT
Press to move to the [Indicated Rate] field, then to enable numeric entry.
Use the numeric keys to type a flow rate for point # 1, then press
NOTE: Enter absolute value of the flow. Flow rate is not direction sensitive. The same calibra-
tion applies to both negative and postitive flow rates.
The highlight moves to the [% Correction] field for point # 1. Press to enable num-
eric entry.
Use the numeric keys to type the required % correction for point # 1.
ENT
Point # (point 1 selected)
Indicated Rate (shows current rate for point # 1)
% Correction (amount of correction applied either (-) or (+) percentage)