Ukraine has initiated a new international project within the framework of the International Organization of Legal Metrology (OIML) aimed at advancing global practices in the calibration of fixed and transportable storage tanks. As an active Member State of OIML, Ukraine - represented by the SE “UKRMETRTESTSTANDART”, regularly contributes to the work of multiple technical Committees and subcommittees. A key area of engagement is Technical Committee 8 (TC 8), Measurement of Quantities of Fluids, and its Subcommittee 1 (SC 1), Static Volume and Mass Measurement.

Within the activities of TC 8/SC 1, SE “UKRMETRTESTSTANDART” proposed developing a new OIML Guide: OIML G 24, Fixed Storage and Transportable Tanks. Calibration Using the Electro-Optical Distance-Ranging Method.

Approval of the Initiative

In October 2025, during the 60th CIML Meeting in Paris, Ukraine’s proposal to develop OIML G 24 was officially approved. The new Guide will establish procedures for calibrating fixed and transportable tanks used in legal metrology, using the Electro-Optical Distance-Ranging (EODR) method with Terrestrial Laser Scanners (TLS). By CIML Resolution CIML/2025/17, the project was endorsed with 69 votes in favor and one abstention. A working group of TC 8/SC 1 members was established to draft the document.

Project Leadership

The proposal submitted to CIML on behalf of Ukraine was signed by:

• Dr. Yurii KUZMENKO, PhD, Deputy Director General for Metrology, CIML Member for Ukraine.

The appointed Project Leader for OIML G 24 is:

• Prof. Oleksandr SAMOYLENKO, DSc, Director of the Scientific and Production Institute of Geometric, Mechanical, and Vibroacoustic Measurements at the SE “UKRMETRTESTSTANDART”.

For secretarial and organizational functions within TC 8/SC 1-including future development and revision of OIML publications- the SE “UKRMETRTESTSTANDART nominated:

• Dr. Oleksandr ADAMENKO, PhD, Senior Researcher at the SE “UKRMETRTESTSTANDART, to serve as Convener of TC 8/SC 1. This nomination was formally approved by CIML.

Objective of the Project

The purpose of OIML G 24 is to enhance the accuracy of volume and mass measurements for liquids in tanks during commercial, customs, tax, and internal accounting operations. It aims to reduce measurement uncertainty to 0.1%-0.3%.

The Guide will unify:

• standards for measurement methods;
• specifications for equipment;
• data-processing procedures;
• uncertainty evaluation methods;
• formats for calibration reports.

Special emphasis is placed on eliminating hidden uncertainty arising from incorrect calculation procedures. The Guide will also integrate modern techniques, particularly 3D laser scanners, to improve accuracy and efficiency. Under current international standards, such as OIML R 71:2008 (Fixed Storage Tanks), OIML R 95:1990 (Ships' Tanks), and OIML R 80:2017 (Road and Rail Tankers)-TLS technologies can approximately double calibration accuracy, delivering substantial economic benefits.

Structure and Development Timeline

OIML G 24 will consist of five parts:

1.      Requirements for automatic measurements;

2.      Requirements for manual measurements;

3.      Requirements for measurements processing, capacity and its uncertainties evaluation methods;

4.      Requirements for report formatting;

5.      Annexes.

The document will address all aspects of tank calibration - from methodologies and equipment specifications to computational algorithms and reporting structures.

Relevance of the Initiative

Existing standards (ISO 7507-4/5, ISO 12917-2, API 2552) provide only a general description of EODR-based methods and lack detailed formulas, algorithms, uncertainty calculations, or correction models. This leads to inconsistent results and potential systematic errors across laboratories worldwide. OIML G 24 will resolve these gaps, serving as a global reference for metrological laboratories and software developers.

International Importance

Implementation of OIML G 24 will:

• reduce losses of oil, fuel, chemicals, and food-grade liquids in global and domestic trade;
• ensure accurate and fair assessment of customs duties and taxes;
• improve operational efficiency for enterprises;
• minimize inventory errors;
• promote rational resource use by governments and private companies.

As a key international instrument, OIML G 24 will harmonize tank calibration approaches, ensuring high accuracy and strengthening global trust in metrological results.