Fill-Rite TS SS F & W Precision Meter - Manual (Page 14)

Procedures & Methods
Flow meters subject to Weights&Measures regulations, or
used in systems where the flow rate can fluctuate, should
be tested at minimum, intermediate & maximum flow rates.
In non-W&M service, a flow meter always operating at a
steady flow rate, can be tested at that flow rate only.
All calibration tests should be:
 Of at least 60 second duration, to minimize the effect of
flow meter error during start-up and shut-down.
 Repeated 3 times to confirm flow meter repeatability.
Flow meters can be calibrated against a prover tank, a pipe
prover or a master meter. Please consult with your distribu-
tor and/or local regulatory agencies to determine methods
available (or required).
 After calibrating a known volume (X) into an accurate
prover, or through a Master Meter (MM), compare with
register reading (Y) and calculate correction:
If using a MM, always correct for MM error as shown on
MM accuracy curve, for the flow rate used during the test.
 When re-calibration has established that a correction is
required, the procedure varies with flow meter configura-
tion and/or the specific electronic register used. Please
refer to register manual for full details & procedures.
A. In some electronic registers, you can enter a revised K
Factor in programming model (the ELNC & EMR³).
B. In some electronic registers, you can run a given vol-
ume, and then tell the register what that volume was.
It will update the K Factor based on this (EMR³).
C. If the flow meter includes the SCL (see pages 24 & 25
for more detail), you can use a small screwdriver to
change the mechanical calibrator setting. Each setting
change (such as from 37 to 38), equals approximately
a 0.03% change:
 When prover/master meter reading is less than
flow meter
register reading, add percentage cal-
culated to original calibrator setting.
 When prover/master meter reading is more than
flow meter register reading
, subtract percentage
calculated from original calibrator.
Circulate product through the flow meter for a few minutes.
Then perform at least 3 more tests, to confirm flow meter
accuracy & repeatability.
 Finally, enter % correction on the permanent flow meter
record.
1 . 14
Flow Meter Calibration
Optional SCL scaler card (not yet approved in the EU)
Mechanical calibrator Jumper for Voltage
for pulse signal. selection (5 or 6-12 VDC)
Flow Meter Calibration
All TS Series meters are accuracy tested prior to shipment.
Data from accuracy testing is not supplied with flow meters,
since results achieved on our test fluid do not apply to actual
liquid of operation, unless the two liquids have identical vis-
cosity characteristics. When calibrated on a liquid with 1 cP
viscosity, we expect that flow meters used on:
0.5 cP liquid will under-register by about 2%
10 cP liquid will over-register by 0.35% to 0.6%
100 cP liquid will over-register by 0.7% to 1.5%
This shift in the accuracy curve illustrates the need for re-
calibration of new flow meters on actual liquid of service,
after installation in place of service. The accuracy curve will
not shift significantly at higher viscosities, even if the actual
operating liquid has viscosities up to 500,000 cP.
Individual flow meters may differ slightly from the norm.
Such variations are corrected through the K Factor pro-
grammed into the register/controller.
Frequency of Calibration
If the flow meter is used in Custody Transfer service (subject
to Weights&Measures regulations), it must obviously be re-
calibrated in accordance with local W&M regulations. In
most cases these regulations call for annual re-calibration,
though different time periods apply in some territories.
If the user is ISO9000 certified, user ISO standards will indi-
cate frequency of re-calibration for instrumentation. Those
rules should be observed.
If neither W&M regulations, nor internal standards apply, our
recommendations are:
A. Calibrate immediately after installation.
B. Re-calibrate after 15-30, 180 and 360 days.
After the run-in calibration and follow-up calibrations, it is
possible to evaluate degree of change under normal operat-
ing conditions. Based on values found, and total volume
being metered under normal operating conditions, decide
whether a 6, 12 or possibly 24 month schedule should be
adopted.
X - Y
X
x 100 = % correction