Overview
EN ISO 4267-2:1995 (ISO 4267-2:1988) - Petroleum and liquid petroleum products: Calculation of oil quantities - Part 2: Dynamic measurement is a CEN-adopted International Standard for the volumetric measurement of liquid hydrocarbons (including LPG) using meters and provers. It standardizes terminology, defines correction factors and equations, and sets rules for the sequence, rounding and significant figures used in meter-proving and dynamic measurement calculations. The standard excludes two‑phase fluids (except for sediment and water in crude oil).
Key topics and technical requirements
- Terminology and definitions: preferred terms (e.g., base volume, meter factor, K‑factor, measurement ticket) to ensure consistent interpretation across operators and systems.
- Correction factors: formalizes principal correction factors and notation, including:
- MF (meter factor) and K‑factor (pulses per unit volume)
- Cts/CPS/Cpl/Ctl - corrections for temperature and pressure effects on steel and on the liquid
- Csw - correction for sediment and water content
- Calculation rules:
- Prescribed sequence for applying corrections (MF, Cts, Cps, Cpl, Ctl, Csw) and method to compute a combined correction factor (CCF).
- Rounding, truncation and significant‑figure rules to ensure identical results from the same data; hierarchy of accuracies for levels such as prover calibration, meter factor and measurement tickets is provided.
- Requirement to complete multiplication before division in single operations.
- Prover and meter calibration methods: worked examples and equations for common proving methods - pipe provers, tank provers, water‑draw, master‑meter methods - and tables (e.g., annex A) for common correction values (Cps for pipe sizes and wall thicknesses).
- Standard reference conditions: default reference pressure 101 325 kPa and temperature 15 °C (with note that national practices may use other reference temperatures).
Applications and practical value
- Ensures repeatable, auditable custody‑transfer and operational volume calculations for fuel terminals, refineries, pipeline operators, bulk fuel distributors and LPG facilities.
- Provides the calculation rules necessary for:
- Meter proving and calibration
- Generating measurement tickets and custody‑transfer documentation
- Implementing temperature/pressure compensation routines in SCADA and billing systems
- Useful for calibration laboratories and metrology teams implementing traceable volumetric standards.
Who should use this standard
- Metering and instrumentation engineers
- Custody transfer and commercial teams
- Calibration laboratories and proving technicians
- Pipeline, terminal and refinery operators
- Software developers of metering and billing systems requiring standardized compensation logic
Related standards (for reference)
- ISO 5024 - Standard reference conditions
- ISO 7278-2 - Proving systems for volumetric meters (pipe provers)
- ISO 2715 - Turbine meter systems
- ISO 8222 - Temperature corrections for volumetric reference systems
- ISO 9770 and ISO 91-1 - Compressibility and volumetric tables
Keywords: EN ISO 4267-2:1995, ISO 4267-2, dynamic measurement, petroleum metering, volumetric measurement, meter proving, meter factor, K-factor, correction factors, prover calibration, custody transfer.
