NMi has taken the initiative to bring together a small group of experts on legal metrology and standardisation of measurement instruments with a select number of international experts on WIM to develop this new WIM standard. The members of this project group cover the broad field of expertise required to develop this practical standard. A standard in structure and content at a quality level suitable for international use. Combine the experts involved in the development of this standard have a combined experience of over 100 years covering both vendors and end-users. Expertise on a variety of WIM technologies, systems, applications and conditions from countries across the globe.
NMi’s WIM Standard is developed by all participating members of the expert group. The standard is open to be used by both buyers and vendors of WIM systems to facilitate their collaboration. Furthermore, we encourage the National Metrology Institute or Bureaus for Weights and Measures in any country to adopt this standard as a basis for national legislation.
NMi Weighing in Motion Standard
For many years three documents, the COST-323, ASTM-E1318, and OIML-R134 have been used to determine the performance of Weigh-In-Motion (WIM) systems. Each document having its own area of use with specific advantages and disadvantages. But none the three covers the applications and operational conditions for WIM systems in for example direct enforcement of overloading under regular highway conditions.
As a consequence national authorities worldwide have to develop their own specifications and test procedures for their national legislation. This has led to the situation where there are several different national sets of requirements on WIM that are not compatible and by many considered too complicated for practical use. This has resulted in unnecessary additional work and costs for both vendors and end-users of WIM systems. The NMi WIM Standard has been developed to overcome these issues. Covering all applications for both high (and low) speed WIM systems.
The NMi WIM Standard Guide serves as a support document for the NMi WIM Standard. The document will explain the scope and application and how these are reflected in the structure of the standard. It explains the different level of performance testing and how the various tests are used in the procedures for acceptance of WIM systems for Legal or Statistical applications. Finally, the document sets out why certain choices have been made in the development of the standard itself.