Liquid Controls DMS Setup - Manual (Page 46)

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Method 2 - Field Proving Technique
In situations where the meter’s accuracy curve is not
provided by the manufacturer, Multi-Point Calibration
must be performed by proving the meter at various flow
rates.
1. Ensure the LectroCount is in Calibration mode. This
is accomplished by removing the switch plate and
rotating the red selector switch counterclockwise to
the 6 o’clock position.
2. Verify Linearization Mode is set to Setup.
3. Start a proving run by pressing the START/RESUME
Key. Monitor Screen 10f: Product Calibration during
this proving run. The meter should be running at
normal high flow rate. Flow Rate field displays the
current flow rate of the meter.
4. When prover is full, press PRINT/END Key on
keypad.
5. Move pointer to Prover Qty and press ENTER to open
a field edit window and enter exact quantity shown in
the prover.
6. From Screen 10f: Product Calibration, move pointer
to Point Number and press ENTER Key to open a
list box window and verify Linearization Point is set
to 1. Press ENTER.
7. Press START/RESUME to begin a new prover run at
the same flow rate as Step 3. Note the maximum flow
rate observed during the proving run. When prover
is full, press PRINT/END.
8. Move pointer to Prover Qty and press ENTER to open
a field edit window and enter exact quantity shown in
the prover. When this is entered, the Percent Error
field will update to show calculated error for that flow
rate.
9. Move pointer to Flow Rate and press ENTER to open
a field edit window and enter the maximum flow rate
observed during the run. Press ENTER.
10. Move pointer to Point Number and press ENTER to
open a list box window and select next point number,
2.
11. Begin a second prover run at a different flow rate.
Press START/RESUME and monitor the display for
maximum flow rate for the run. When prover is filled,
press PRINT/END.
12. Move pointer to Prover Qty and press ENTER to open
a field edit window and enter exact quantity shown in
the prover. When entered, the Percent Error field
will update to show the calculated error for that flow
rate.
Multi-Point Calibration
When Point Number programming is complete, move
pointer to Linearization Mode and press ENTER to open
the list box window with options Applied and Setup. Move
pointer to Applied and press ENTER.
This puts Linearization algorithm into effect. If error
message ADJACENT POINTS OUT OF 0.25% RANGE
is displayed, Applied function will not take effect. The
Linearization Points will need to be re-selected to ensure
no two adjacent points, based on flow rate, are more
than 0.25% apart in their corresponding Percent Error
fields.
Field prove the meter using the method described for
Single-point Calibration. Assuming data provided by
manufacturer is correct, it should be possible to fill a
prover at any flow rate within the linearized range and
obtain near perfect accuracy.
When
Setup is selected for Linearization Mode, the
algorithm is not activated. Setup should be used during
the multi-point calibration process. Applied is used after
the multi-point calibration process is completed.
Method 1 - Continued