Flow meter calibration – Fill-Rite TS SS Electronic Precision Meter User Manual
Page 8
These shifts in the accuracy curve illustrate the need for field
recalibration of new flow meters after installation in place of
service.
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 days.
C. Re-calibrate after 180 & 360 days.
After the run-in calibration (B) and follow-up calibrations (C),
it is possible to evaluate degree of change under normal
operating conditions. Based on values found, and total vol-
ume being metered under normal operating conditions, de-
cide whether a 6, 12 or possibly 24 month schedule should
be adopted.
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, a master meter or a scale. Please consult with your
distributor and/or local regulatory agencies to determine
methods available (or required).
When X = known volume dispensed, and Y = volume shown
on the register, use this formula to calculate the correction
required:
When the register is showing less than the volume actually
dispensed, the K Factor (number of pulses/unit of volume)
must be decreased accordingly. This is programmed in the
register, or possibly corrected via the mechanical calibrator if
the SCL signal conditioner is included in the assembly.
Repeat the test 2-3 times, to confirm flow meter accuracy
and repeatability.
If calibration is now correct, enter % correction on the per-
manent flow meter record, and re-seal the flow meter.
1 . 8
Flow Meter Calibration
TS Series meters in E●● & S●● assembly have an internal
pulser. The pulse signal generated by the flow meter, can
be fed directly to most electronic registers. In such assem-
blies, flow meter calibration (or re-calibration) is through
correction of the K Factor (number of pulses/unit volume) in
the electronic register.
In some cases, an optional signal conditioner is added on
the pulse signal:
PIA-300 pulse isolator/amplifier/splitter
Provides 2 identical signals out, sinking or sourcing.
Required when signal travels more than 100’ (30 m).
Recommended if signal goes to non-FPP electronics.
SCL pulse scaler/calibrator/linearizer
If pulse frequency exceeds register capacity at maximum
flow rate. This can occur at surprisingly low flow rates
(see below).
If electronic register requires a scaled pulse value (1, 10,
100 or 1000 pulses/volume unit).
If local authorities demand a mechanical calibration de-
vice. The SCL includes two dials with setting from 00 to
99. Changing the setting by 1 unit, represents approx.
0.03% correction to the pulse signal.
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, if the flow
meter is not field recalibrated on actual liquid of service, we
expect that the flow meter will be:
Under by 1-2% on a liquid with 0.5 cP viscosity.
Over by 0.35% to 0.6% on a liquid with 10 cP viscosity.
Over by 0.7% to 1.2% on a liquid with 100 cP viscosity.
The accuracy curve will not shift significantly at higher vis-
cosities, even if the actual operating liquid has viscosities up
to 500,000 cP.
X - Y
X
x 100
= % correction
Register m odel:
Frequency lim it:
METER
MODEL
GPM
P P G
LPM
ppl
TS10C
40
136
150
35.9
=>
91
Hz
TS15C
60
108
230
28.5
=>
108
Hz
TS20C
100
101
380
26.7
=>
168
Hz
150
72
570
19.0
=>
180
Hz
TS30C
200
51
760
13.5
=>
170
Hz
Interm. duty
250
945
=>
213
Hz
Interm. duty
300
1135
=>
255
Hz
Frequency at 100%
of model capacity.
1667 Hz
EMR
3
Pls consult with register manufacturer for other registers
ELNC
400 Hz
LCR-II™
1500 Hz