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Enhancing custody transfer measurements through digital technology

software is Spirit SmartCen, jointly
developed by ABB Spirit and Petronas FIGURE 3 Available verification techniques for measurement devices
(Figure 2).

WHY USE MEASUREMENT
DEVICE VERIFICATION WHEN ON-BOARD VERIFICATION (IN-DEVICE)
CALIBRATION IS FAR MORE
ACCURATE? CUSTODY
Measurement device verification is an TRANSFER INTERNAL ON-DEMAND VERIFICATION SOFTWARE
in-situ tool for checking product METERING DIAGNOSTICS (PC APP)
accuracy and health. It is not calibrated SYSTEM
and typically doesn’t conform to
international or OGC standards. AUTOMATED REMOTE VERIFICATION
Proprietary verification software (SERVER/CLOUD APP)
developed by the measurement device
manufacturers utilises on-board
diagnostic information to establish the
device condition.

Examples of the types of information with the result outputted to higher CONCLUSION
available within a device include: level systems. Measurement devices Gas operators can use verification and
■ Sensor transducer internal tend to be resource constrained, and mismeasurement management
measurements (resistance, the data from each test is not software to better utilise system data.
capacitance, inductance, frequency etc) typically stored or available for These software tools contain
■ Meter output accuracy (analog post-processing. However, access to embedded expert knowledge to
pulses or 4-20mA, digital outputs) the result provides an operator with interpret system data and deliver
■ Cable insulation resistance meaningful information to act upon actionable information for the
(pass, marginal pass, marginal fail, fail). enhancement of operational
To identify any change in the Verification software installed on a performance. With an ideal custody
condition, the results are compared computer communicates transfer system, operators use
with a fingerprint test that is used as a independently with the device, mismeasurement management
benchmark. collecting diagnostic data and software to efficiently deal with
Any deviations from this benchmark performing a verification test. This identified errors when they arise.
are indicative of a potential problem, method allows a comparison with Automated/regular verification of
which can be pinpointed and rectified previous test results/trending measurement devices supports
before it escalates. parameters to identify long-term identifying potential issues before
Typically, the fingerprint is degradation and certificate generation mismeasurement errors occur and
generated when the measurement as a proof of test. These software provides operators with the
device is first manufactured and is applications typically rely on the confidence to extend the period
performed under laboratory operator to manually perform the between tests.
conditions. An operator may also test. The build-up of historical data for
prefer to create a fingerprint test after trending and predictive failure FUTURE DIRECTION
the measurement device is detection may take time to be The data from the system will
commissioned within the custody statistically meaningful. continue to be refined, providing
transfer metering system, operating in Automated remote verification additional value. Operators can expect
‘real-life’ conditions. involves hosting a server/cloud-based machine learning to be used for
Verification tests, however, do not version of the verification software detecting an increased number of
offer the confidence in measurement and, at a pre-defined interval, anomalies before they develop into
accuracy that flow testing, proving or collecting the diagnostic data and mismeasurement, with artificial
calibration provide. If periodic flow performing the verification test. intelligence generating prescriptive
testing does not result in a change in Automated verification is a form of maintenance orders with automatic
the calibration factor and sequential condition monitoring for which the spare parts delivery. Systems will
verification tests additionally show no data is stored in a historian program. operate at higher levels of accuracy
change in test results, an operator Trends can easily be reviewed by and availability with a reduced cost of
might instead reasonably consider operators and maintenance teams and maintenance, ultimately ensuring the
extending the period between flow the application can be programmed to correct custody transfer revenues, and
tests, and thus save money. provide alerts when a test deviates potentially saving operators millions
Verification technology can be from the original fingerprint test of dollars each year. ■
implemented in a number of ways result. These alerts assist in identifying
(see Figure 3). some of the problems experienced by REFERENCES
On-board verification provides operators in the gas industry, helping Spirit IT Mismeasurement Management, Han van Dal, 2018.
Available at: www.crt-services.com/download/han-van-dal-
continuous self-checking of the device to reduce mismeasurement time. spirit-mismeasurement-management-pdf

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