CNG and LNG truck fuelling measurement and delivered quantity verification.
CNG and LNG truck fuelling operations involve high transaction volumes and individually small quantities, where cumulative measurement errors across a fleet or terminal can represent material commercial exposure. FUTUREGAZ reviews the metering basis, calibration status, and delivery records for CNG and LNG dispensing operations, supporting both operator reconciliation and third-party verification.
At CNG filling stations and LNG truck fuelling points, quantity is measured by mass flow meters or corrected volumetric meters. Calibration drift, dispenser configuration errors, and inconsistent delivery record practices are the most common sources of discrepancy. The measurement chain from bulk storage through to individual vehicle delivery involves multiple instruments and data capture points, each of which can introduce error.
FUTUREGAZ supports metering accuracy review, delivery record audit, and commercial settlement reconciliation for CNG and LNG truck fuelling operations. Work is structured around the applicable weights and measures requirements and the specific metering technology in use.
What this covers
Dispenser calibration review
Review of dispenser meter calibration records, proving history, and compliance with the applicable national weights and measures standard for the metering technology in use.
Mass meter verification
Assessment of Coriolis or thermal mass flow meter performance, calibration traceability, and installation configuration against manufacturer and standard requirements.
Delivery record audit
Review of transaction records for completeness, consistency, and compliance with contractual requirements, including cross-reference against bulk storage movements.
Settlement reconciliation
Reconciliation of dispensed quantities against bulk deliveries received, identifying unexplained differences and producing a structured loss and variance report.
Stock balance
Assessment of site stock balance methodology, including opening and closing inventory, bulk deliveries, and total dispensed quantities across the reporting period.
Operator programme support
Support for large operator programmes involving multiple fuelling sites, including standardisation of measurement methods and reconciliation procedures across the network.
Applicable standards and references
LNG measuring systems
OIML recommendation covering measuring systems for the dynamic measurement of cryogenic liquids including LNG, applicable to LNG dispensing at fuelling stations.
Gas meter conversion devices
European standard for volume conversion devices for gas meters, relevant to CNG metering and correction to standard conditions.
Turbine metering
AGA standard referenced for gas flow metering at CNG compression and dispensing installations.
National weights and measures
Applicable national metrology authority requirements for commercial metering, type approval, and in-service verification of fuel dispensing equipment.
Frequently asked questions
How is CNG or LNG quantity measured at dispensers?
CNG is typically measured by corrected volumetric or mass flow meters at the dispenser, with quantity expressed in kilograms or standard cubic metres. LNG is measured by Coriolis or thermal mass flow meters, with quantity expressed in kilograms. Both require type-approved meters verified to the applicable national weights and measures standard.
What causes truck fuelling discrepancies?
Common causes include calibration drift on dispenser meters, configuration errors in the meter factor or correction algorithm, losses during hose depressurisation, temperature effects on LNG density, and inconsistent data capture between dispensing records and bulk storage movements.
What records are required for LNG truck deliveries?
Typical requirements include delivery dockets showing date, time, vehicle identification, quantity, meter serial number, and operator signature. These should be retained and cross-referenced against site stock movements and bulk deliveries received to support periodic reconciliation.
When should a truck fuelling station measurement system be audited?
An audit is useful when reconciliation variances exceed normal operating tolerances, following meter replacement or repriming of an LNG system, before renewing a fuelling supply contract, and as a periodic check on metering accuracy and data completeness.
Discuss a truck fuelling measurement requirement.
Describe the fuel type, site configuration, and the measurement concern. We will respond with an appropriate approach.
Send an enquiry contact@futuregaz.com