Overview
EN ISO 6551:1995 is an international standard developed by CEN, titled "Petroleum liquids and gases - Fidelity and security of dynamic measurement - Cabled transmission of electric and/or electronic pulsed data (ISO 6551:1982)". This standard provides comprehensive guidelines for ensuring the integrity and security of quantitative measurements in the petroleum industry, specifically for systems using cabled transmission of electric/electronic pulsed data. The main objective is to secure the fidelity of primary measurement indications, which are fundamental for dynamic measurement processes in petroleum liquids and gases.
The document outlines recommendations for the design, installation, use, and maintenance of relevant equipment, ensuring high standards of reliability in the measurement and data transmission process. While regulatory and safety requirements are not fully detailed, general safety notes are provided to guide users.
Key Topics
- Fidelity and Security of Measurement Systems: Ensuring that the measured and stated quantities accurately reflect actual values, guaranteeing trust in financial and operational processes such as custody transfer and revenue accounting.
- Levels of Security: The standard defines five distinct levels (E to A) of system security, ranging from basic error reduction (Level E) to advanced real-time monitoring, correction, and alarm signaling (Level A).
- Primary vs. Secondary Indications: Differentiation between primary indication (core measurement and its direct transmission system) and secondary indication (auxiliary or backup systems that provide additional readings).
- Design and Installation Criteria: Emphasis on using quality components, robust system design to minimize errors, noise immunity, and proper installation practices.
- Error Sources & System Testing: Identification of common error sources such as electrical noise, transients, and environmental influences, alongside recommendations for regular inspection, maintenance, and testing protocols.
- Maintenance and Inspection: Encourages planned, scheduled maintenance and competency of personnel involved in the operation and servicing of measurement systems.
Applications
The scope of EN ISO 6551:1995 primarily covers:
- Custody Transfer: Providing reliable measurement data for the transfer of petroleum products between parties.
- Revenue and Royalty Accounting: Securing accurate quantitative information, vital for financial settlements.
- Stock and Loss Control: Ensuring precise metering for inventory management and loss prevention in production, refining, storage, and transportation of petroleum liquids and gases.
- System Integration: Guiding manufacturers and operators in integrating secure pulsed data transmission into their metering and monitoring systems for liquids and gases.
- Instrumentation and Control: Offering a framework for the design and operation of electronic signal transmission and measurement within hazardous and non-hazardous environments.
Related Standards
This standard is closely related to, and sometimes used alongside, the following:
- ISO 4266 series: Measurement of petroleum and liquid hydrocarbons.
- ISO 5167 series: Flow measurement in closed conduits.
- ISO 3171: Petroleum liquids - Manual sampling.
- ISO 3170: Manual sampling of crude petroleum and liquid petroleum products.
- Standards for Electrical Safety: For specific regional installation and operational safety compliance.
Practical Value
Adhering to EN ISO 6551:1995 supports the petroleum industry in:
- Minimizing disputes over measured quantities by standardizing measurement integrity.
- Meeting mutually accepted accuracy requirements in commercial transactions.
- Ensuring the robustness and long-term reliability of metering installations.
- Facilitating compliance with local and international legal metrology and basic safety obligations.
- Enhancing operational efficiency and maintaining data security across dynamic measurement systems.
Keywords: EN ISO 6551, petroleum measurement, dynamic measurement fidelity, pulsed data transmission, cabled signal security, primary indication integrity, petroleum liquids and gases, custody transfer, measurement standards, electronic signal transmission, instrument calibration, metering system maintenance.