Legal for Trade weighing system: invoicing by weight

Legal for Trade refers to an officially approved weighing system that may be used for weight-based commercial transactions. This approval ensures that the weighing system meets strict accuracy and reliability requirements. Since the repeal of the calibration law in 2006, the process of approval is formally referred to as inspecting rather than calibrating. Thus, instead of calibrating a scale, we have since officially referred to it as Legal for Trade.   

The International Organization of Legal Metrology (OIML) establishes uniform guidelines worldwide to ensure that all weighing systems meet the same standards. Always inform yourself in advance about the legal requirements within your country.  

Legal for Trade weighing systems are required in a variety of applications. Consider raw material suppliers, for example, who sell goods by weight. Carriers, including air cargo companies, also rely on calibrated systems to bill correct weights. These systems ensure that invoices are correct, which is essential for reliable and efficient operations. Consequently, using Legal for Trade weighing systems also reinforces customer and partner confidence in the accuracy and fairness of transactions. 

A Legal for Trade weighing system is essential for companies that bill by weight. These systems can be integrated into various types of warehouse trucks, forklifts and pallet trucks. All components of the weighing system, such as the indicator and load cells, must meet strict requirements for accuracy and reliability. Certification is provided by a locally designated institute that tests for various aspects such as accuracy, security and the influence of external factors, for example. Each system must also be equipped with a level switch to prevent weighing errors due to tilting and must make the weight readable directly to the operator. 

The inspection process of a weighing system involves checking and, if necessary, recalibrating the system to meet legal standards. Reference weights are used to determine accuracy and correct any discrepancies. After successful inspection, the weighing system is delivered with a certificate showing that it complies with OIML guidelines. This certificate contains important information such as the manufacturer, the serial number, and the gravity factor used, ensuring that the system is suitable for commercial use. 

Government agencies inspect weighing systems used for weight-based billing. These checks are often unannounced, and it is the user's responsibility to ensure that the systems meet legal standards.  

In many countries there is a legal requirement for periodic re-inspection. But even if this is not the case, we recommend an annual inspection. This will ensure that your systems remain accurate. It is convenient to combine the re-inspection with regular maintenance to minimize disruption to your business processes.  

Re-inspections may only be performed by a representative of a certified metrological institute. This may be a RAVAS representative or another certified organization. RAVAS is certified by the Netherlands Metrology Institute (NMi) to perform both initial verifications and re-inspections of weighing systems in the Netherlands. These inspections are performed according to European Directives 90/384/EEC and 93/86/EEC on non-automatic weighing systems, and Module D of Council Decision 93/465/EEC. In other countries, we are happy to prepare the inspection for you, so that your weighing system is approved by the local authorities without any problems.