MFM Accuracy: Understanding Why Singapore's TR 48 is Superior to EU MID

in Singapore close to a hundred barges have been successfully accredited against TR 48

Anybody working in the bunker industry should be well familiar by now of the impending mandatory use of mass flow meters for bunker deliveries in Singapore from 1 January 2017 onwards. Singapore's move to embrace technology and upgrade from historical archaic manual measurement practices to sophisticated use of meters to ensure irrefutable custody transfer quantities delivered to ships is to be applauded. Welcome to the 21'st century bunker industry it was high time and a long time coming!

Singapore's MPA together with industry stakeholders have developed a robust accreditation process in order to ensure meters are reading accurately once installed and tested on bunker tankers so ship owners can have higher confidence that they will only pay for the fuel they receive - nothing more and nothing less.

Over the past year, several bunker operators are installing meters in Hong Kong, Rotterdam and Fujairah. Some of these operators have been toying with the idea of getting meters accredited using EU MID (Measuring Instruments Directive) as a basis to demonstrate accuracy of an installed meter on a bunker tanker. Operators considering this should do so at their own peril and should seriously consider adopting the Singapore TR 48 (technical reference for bunker mass flow metering) approach if they don't want their investments in mass flow meter to turn out to be a cat in the bag.

Although the EU MID is a directive dealing with the accuracy of legal metrology in intra trade environments across a whole plethora of industry sectors but for bunkering applications it is not ideal or applicable given the nature of its operation.

The MID approach to mass flow meters on bunker tankers is simply not good enough.  In Singapore this is not a problem as MPA mandates the accreditation process of mass flow meters on bunker tankers to be carried out in line with TR 48. In other ports however it is a different story as the local port authorities do not currently have processes in place which bunker operators need to adhere to. Therein lies the trap called "choice". Although the MID approach to some extent can deal with the measurement accuracy of a mass flow meter it does not necessarily take into account the environment the meter is installed or operated in. Where the meter is installed, secured and operated at affects the overall meter performance and more often than not impact accuracy.

TR 48 explicitly details criteria that must be conformed to before a meter can be viewed as accredited to be accurate.

1. Traceability to SI mass & meter selection
2. System integrity requirements (system sealing and operations procedures)
3. Acceptance test requirements for legal metrology calculations

The aforementioned criteria should result in the mass flow meter system to operate within 0.5% overall measurement uncertainty.

The MID approach lacks key steps such as but not limited to the following.

• No operations procedure.
• No conduct of field testing for operation assessment
• Focus security only on delivery instead of bi-direction loading and delivery
• Sealing not mandated to be carried out by an independent third party, such as Class Societies or inspection companies.

The above are just a few examples of differences between TR 48 and MID approach to mass flow meter system accuracy.

Finally let us not ignore that in Singapore close to a hundred barges have been successfully accredited against TR 48 which was ultimately developed for and by the industry. The experience with TR 48 is well understood by operators installing mass flow meters. The MID approach is not.  It might be attractive to operators at face value to use the MID approach as it certainly is less costly an approach than following TR 48 but also less reliable.