Calibrations are all carried out and certified to appropriate international standards. Calibration is by process, which may be by varying methods such as optical, strapping, or metering, depending on type/design/siting and preferences. Meters used for flow measurements can be calibrated by proving of the meters using master reference equipments. The process of calibration and selection of equipment/personnel to be used is broadly outlined as below (preparation processes can usually be concluded in very short time frames, even down to same day where all information is available and straightforward):
• Assessment of tank/meter type(s) to be calibrated and product(s) it is to be used for.
• Assessment of tank/meter location/condition during calibration.
• Confirmation of suitability for calibration.
• Assessment of appropriate preferred methods to be used in calibration.
• Agreement of methodology, dates and conditions for calibrations to be carried out.
• Selection/allocation of equipments and personnel and scheduling.
• Mobilisation to site/Calibrations/Return from site.
• Calibration calculations and table preparation.
• Verification processes and validation.
• Issuance of calibrations.
All calibration exercises record pertinent information on method of calibration/international standard applied and the recommended dates of recalibration required to comply with minimum requirements of the standard.
To ensure that uniformity and compliance standards are achieved, we adhere to internationally recognised standards of operation. These are not just internal guidelines, but incorporate the standards of internationally recognised bodies.
The standards to which our tank calibration is traced to are:-
ISO 7507 - part 1 to 4, ISO 12917, API (American Petroleum Institute) 2550, API 2551, API 2552, API MPMS 2.8.A, from which the national standards and rules are derived. The ISO rules have also been recommended by OIML (International Organization of Legal Metrology)
The calibration can either be by Prover Tank, Master Meter or Pipe prover method. The method and process to be used employed at any particular time depends on the consideration of all apropriate factors.
The frequency of calibration of Flow meters could be quarterly or bi-annually depending on usage and throughput of the meter.
The international standards to which these calibrations are traced are:
MANUAL OF PETROLEUM INSTITUTE Part X, Section 2 and API standards 1101,2531 and 2531. Other related standards: API MPMS 11.2.2:1st, API MPMS 4.1:2005, ANSI Z11.170:1971, ISO DIS 2714:1971