What to consider when connecting IT systems with legal-for-trade scales
Many companies ask themselves whether a commercially available PC has to be calibrated if it is connected to a scale whose measurement results are used in business transactions. The short answer is: No, the PC itself does not have to be calibrated as long as certain requirements are met!
The most important legal basis for this can be found in the Measurement and Verification Act (MessEG) and the Measurement and Verification Ordinance (MessEV).
Prerequisite: A weighing indicator that complies with calibration law
With scales from ESSMANN | Waagen & Automation, the situation is usually clear: the scales that are placed on the market are already equipped with a verifiable weighing electronics (weighing indicator). This forms the heart of the scale and ensures that the measured values are determined in a traceable manner.
ESSMANN scales that are to be used for commercial purposes undergo the legally prescribed conformity assessment procedure at the time of purchase. conformity assessment procedure. This procedure confirms that the scales meet all essential requirements for measurement accuracy, measurement stability and testability – comparable to an initial verification. This means that the scales are immediately ready for use in business transactions, for example for invoicing by weight.
PC as a “downstream device” – what is permitted
After the conformity assessment procedure further IT components, such as PCs or software solutionscan be connected to the scale for further processing of the measurement data. These IT units themselves do not have to be calibrated – on condition that the scale or an upstream data memory that complies with calibration law stores or outputs the measured values unchanged, permanently and verifiably. The weighing values must be traceable so that they can be verified from a freely programmable data management system.
This is because customers must be able to clearly see on receipts or invoices that the measured value comes from a calibrated device.
Caution when processing data: legal certainty requires expertise
Although connecting a PC to a legal-for-trade scale is permitted in principle , the processing of the measured values in business transactions is subject to strict requirements. It is not permissible to simply “somehow” transfer or process the data. Instead, numerous criteria relevant to legal metrology must be observed to ensure that the entire system remains legally compliant.
These include, among others:
- Complete traceability of all relevant weighing processes,
- a unique alibi number (measured value ID),
- the correct assignment to the time of the measurement (date/time),
- the reference to the specific scale (e.g. via serial number or location identifier),
- the immutability of the data,
- and, last but not least, secure, permanently retrievable archiving, e.g. via a certified data storage system.
These requirements are so complex that even small errors can lead to violations of measurement and calibration law – with corresponding legal and economic risks. We therefore strongly advise against implementing the integration independently.
Rely on our expertise: The experts at ESSMANN | Waagen & Automation know exactly what is important – and ensure that your scales, including PC connection, can be operated in compliance with calibration law, reliably and efficiently.
Measure on the safe side with ESSMANN
The combination of a verified scale and a connected PC is therefore legally permissible if the interface is properly regulated. With a scale from ESSMANN | Waagen & Automation, you are ideally prepared – because it meets all the technical and legal requirements for a direct start in legal-for-trade applications.
Do you have questions about integrating your scales with existing IT systems or selecting suitable software solutions? software solutions? Then talk to us! Our team of experts for scale construction, automation and legally compliant data processing will be happy to advise you.
