Liquid Controls LectroCount LCR-II E36 Series Setup & Operation page 24

MULTI-POINT CALIBRATION (CONT'D)
Step 5:
Refill the prover at the same flow rate as Step 4 to verify that the meter remains within tolerance
limits. Assuming that the data provided by the meter manufacturer is correct, and that proper
technique was used for selecting and entering the multi-point table, it should be possible to fill the
prover at any flow rate within the linearized range and obtain an error near zero.
2. FIELD PROVING TECHNIQUE
When the meter's accuracy is not provided by the manufacturer, points to enter into the multi-point calibration table
need to be determined by field proving at various flow rates.
Step 1:
Start a proving run of the meter while viewing PRODUCT CALIBRATION - Screen 3 at the normal
high flow rate of the system while the LINEAR
press PRINT and adjust the PULSES/UNIT by entering the actual PROVER QTY (see Page 22).
Product Calibration - Screen 3
#A
1
Step 2:
Go to of PRODUCT CALIBRATION - Screen 7. With РТ
start a new prover run at the same flow rate as Step 1. During prover filling, note the maximum RATE
that is displayed. When the prover is filled, press PRINT. Advance to PRODUCT CALIBRATION -
Screen 8. Enter the volume delivered to the prover in PROVER QTY. The %ERROR field will then
display the calculated error for that rate. This should be a very small value since Step 1 "zeroed" the
meter at the same rate. Return to PRODUCT CALIBRATION - Screen 7 and enter the maximum flow
rate observed during prover filling in RATE for PT
Product Calibration - Screen 7
PTA RATE
1 0.00
Step 3:
A
With PT set to the next point and LINEAR
rate. During prover filling, note the maximum RATE that is displayed. When the prover is filled, press
PRINT. Advance to PRODUCT CALIBRATION - Screen 8. Enter the volume delivered to the prover
in PROVER QTY. The %ERROR field will then display the calculated error for that rate. Return to
PRODUCT CALIBRATION - Screen 7 and enter the maximum flow rate observed during prover filling
in RATE forthat PT
Step 4:
Continue proving at other flow rates using additional PT
Step 3. A minimum of three points is recommended (high, medium and low flow) to obtain a good fit
to the curve. All ten points can be used to obtain optimum results. Any unused points should be left at
RATE=0 and %ERRQR=0.
Step 5:
Set the LINEAR
LCR-II will re-sort the multi-point table and display the points in descending order by RATE. Do not
be alarmed if the data changes in a given PT
0.25% RANGE is displayed, APPLIED will not take effect and more points will need to be added to
ensure that no two points adjacent to each other are more than 0.25% apart in %ERROR.
MULTI-POINT CALIBRATION -
PULSE/UNIT
2222.000000
UNITSA
GALLONS
A
.
A
field to APPLIED and enter it. This puts the linearizing algorithm into effect. The
A
field is in the SETUP mode. With the prover full,
PROVER QTY
0.000
Л
set to 1 and LINEAR
A
1.
RATE BASEA
PER MINUTE
A
still set to SETUP, start a prover run at a different flow
A
numbers following the same procedure as
A
. If the error message ADJACENT POINTS OUT OF
LCR-II SETUP
UNITS
GALLONS
A
still set to SETUP,
%ERR0R |
0.000
25