Review of the International Standard ISO 2975 on Tracer methods for the measurement of single-phase flows in closed conduits

Flow rate measurement is the most applied radiotracer method for online calibration and mass balance control in industrial processing. Better than 1-2% accuracy is achievable.

ISO Standards for measurements of fluid flows with tracer methods drafted years ago have been as follows:

ISO 2975 Measurement of water flow in closed conduits-Tracer methods, which consists of 7 parts, some of them never applied and others became obsolete.
ISO 4053 Measurement of gas flow in conduits -Tracer methods, which has been withdrawn for unknown reasons in 2003 leaving a void on this subject.

It is due time to review the existing ISO 2975, in the light of new development in radiotracer methods and industrial processing market.

The Sub Committee (SC) 5 of Technical Committee (TC) 30 of International Standardization Organization (ISO) - shortly: ISO/TC 30/SC 5 - is responsible for periodically reviewing ISO standard in the field of fluid flow measurements. Currently, the SC5 consists of 25 P member states and 11 observing member states (O-members).

Every five years the ISO TC30 SC5 initiates a so-called systematic review of each ISO standard. The last one for the ISO 2975 standard was carried out in 2018.

American Society of Mechanical Engineers (ASME) has adopted the American National Standard MFC-13M – 2006, which merges both ISO 2975 and ISO 4035. This Standard defines the terms and principles needed for intelligent consideration of tracer methods for any application, it can be serving as a good model for reviewing the ISO 2975.

The International Atomic Energy Agency (IAEA) and the International Society of Tracer and Radiation Applications (ISTRA) invites experts from all over the world to participate in the reviewing process of the existing ISO standards, formulating a more comprehensive, simple and universal ISO standard in this field. The new Standard on tracer methods for the measurement of single-phase fluid (gas or liquid) flows in closed conduits, will respond to the demand of industrial end-users.