TCS 682 FLOW METER CALIBRATION
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1. |
It is important to test the repeatability
and accuracy of your meter. To test repeatability:
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A.
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Run a fast
(high gallons-per-minute) test in your prover and record
how much the meter is over or under registering. Do not
change the meter's calibration.
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B.
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Run a slow
(low gallons-per-minute) test and again record how much
the meter is over or under calibration.
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If the results from the fast and the slow
test are the same or close to the same, the meter can be
successfully calibrated. If the test results differ
beyond the rated tolerance of the meter (0.2% for the 682
meter), then repairs are necessary before the meter can
be calibrated.
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2. |
A valve or nozzle must be at the end of the
delivery hose (at the prover).
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3. |
Turn on the pump and purge the system of air.
Leave the pump on.
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4. |
Shut off the valve at the end of the
delivery hose and let the system pressurize.
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5. |
Wet the prover and empty it, letting it drip
for 30 seconds.
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6. |
Reset the register on the meter to "0". |
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7. |
Fill the prover to the line marked "0" |
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8 |
Record what the register reads. Every 1/10
gallon difference between the register and the 5 gallons
known to be in the prover equals a 2% (+ or -) inaccuracy.
For example, a reading of 4.9 gallons on the register,
compared with a 5 gallon prover filled to the "0"
line means the meter is giving away 2% of the product it
meters.
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9. |
The top disc on the calibrator has a tab
sticking up. The tab is marked with a "plus"
product and "minus" product. By turning the
disc in one direction or the other, product delivery
will be increased or decreased.
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10. |
A full revolution of the disc will change
the calibration of the meter 3%. Therefore, if the meter
shows 4.9 gallons on the register, the disc should be
turned 2/3 of one revolution (2%) in the minus
direction, since in this case we want less product
through the meter (5 gallons passed through it in the
test, and only registered (4.9 gallons).
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11. |
Empty the prover and let it drip for 30
seconds.
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12. |
Run a second test and make a fine adjustment;
and then another test to check your fine adjustment.
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13. |
Replace the pin into the disc, and seal it
with the seal wire.
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Note: If your meter has a mechanical or
electronic preset, it should be set high enough so that
it doesn't affect the calibration process. Only a valve
at the prover should be used to control the flow during
calibration.
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