Calibrated Package Scale

You can identify a new, calibrated package scale by the EU conformity marking on the nameplate: CE, next to it the black “M” in a rectangle and the two-digit year of the marking, as well as the four-digit identification number of the notified body. For new scales, this combination indicates the legally required conformity assessment, which has generally replaced the former initial calibration since 2015. Important: The marking must be part of the scale and legible. Additionally, the scale should be designated as suitable for use subject to calibration, typically with Accuracy Class III as well as specifications for maximum load and minimum load.

A DAkkS calibration does not replace legal metrological verification because it only documents the measurement deviation but does not provide legal metrological approval for commercial use. For a package scale subject to legal metrological verification, measurement and verification regulations require a verified or conformity-assessed measuring instrument. Calibration therefore verifies accuracy but does not confirm legal suitability for weighings relevant to billing. Even a DAkkS certificate does not turn an uncalibrated scale into a calibrated one. In practice, this means: Calibration can be useful for internal quality or process controls, but for applications subject to legal metrology requirements, you also need valid legal metrology certification or a legally recognized conformity mark.

A verification weighing is decisive for acceptance if its result directly triggers a decision with external implications. This is the case when the weight determines whether a shipment is accepted, rejected, paid for, subject to a subsequent charge, or rejected due to a defect. Unlike a mere internal check, this is no longer just a matter of guidance, but rather a binding basis for action toward a third party. Typical examples include weight discrepancies in incoming goods or returns, which give rise to complaints or reimbursement issues. Whether the weighing is specifically called a “checkweighing” is irrelevant. The only determining factor is whether the result supports a business- or legally-relevant decision.

Using an uncalibrated package scale in business transactions is risky if its measurement results are used for legal or business-related purposes. In such cases, the measurement value lacks the necessary legal validity. This can not only trigger objections during inspections but also have practical consequences: invoices become vulnerable to challenge, complaints are harder to resolve, and the ability to provide evidence in the event of a dispute is compromised. Added to this are financial risks resulting from systematic over- or under-billing. Particularly in the shipping sector, where weights are often directly incorporated into downstream processes, non-compliant weighing can quickly impact customer relationships, billing accuracy, and the reliability of internal processes.

No. A package scale is generally not subject to calibration requirements for purely internal control weighings. The key factor is that the result is used exclusively for internal control purposes—such as plausibility checks, warehouse processes, or preliminary checks—and has no external impact. However, as soon as the measured weight is used to calculate prices, determine shipping costs, bill for services, or make decisions regarding acceptance or rejection of goods in dealings with third parties, the legal classification changes. For companies, therefore, a clear organizational separation is particularly important: internal use on one hand, legally relevant use on the other. Even if calibration is not required, the scale should operate reliably from a technical standpoint to avoid process errors.

A package scale is subject to calibration requirements as soon as its weighing results form the basis for calculating shipping fees, freight charges, or postage owed to third parties. The decisive factor, therefore, is not commercial use alone, but rather its use for billing purposes in business transactions. A typical example: You weigh a package and use that weight to calculate the price for the customer or to settle an invoice with a shipping service provider. In that case, the scale must be used in compliance with calibration regulations. The legal basis for this is the Measurement Act (MessEG) and the Measurement Ordinance (MessEV). If, on the other hand, the weight is recorded only internally and has no impact on prices or fees, there is no calibration requirement for this purpose.

In the context of a package scale, “calibrated” means that it is approved for legally regulated use in commercial transactions and has been tested to ensure it falls within its permissible error limits. In the day-to-day shipping operations at PackageHERO®, this means: The scale may be used for weight-related, legally binding transactions if its labeling and calibration status are correct. For new devices, this is typically ensured through the conformity assessment; this can be identified by the corresponding marking on the device. Important: “Verified” is not the same as merely “calibrated” or “adjusted.” For businesses, “verified” is therefore primarily a legal and safety issue: reliable measurement results, traceable processes, and accurate weight data in commercial use.

When purchasing a calibratable parcel scale, companies should first clearly define the specific application: Whether it’s for shipping billing, a packing station requiring legally compliant weight measurements, or integration into DWS processes, the scale must be precisely suited for that purpose. Therefore, the most important factors are a design suited to the actual shipments and stable integration into software, workstations, or conveyor systems. Equally important are clear device documentation, practical service, and the ability to continue operating the scale during routine operations without significant effort and to have it verified on schedule. A sound purchasing decision is therefore based not only on the measuring device itself, but on the entire process in which it is used.

The minimum load is so important in daily operation because it marks the lower limit of the permissible operating range. If an item being weighed is below this limit, a value may still be displayed, but it is not reliable enough for legal purposes. Especially with very light shipments, bags, or small parts, this can easily give the impression of an accurate measurement, even though the scale is operating outside its suitable range. For companies, this has direct consequences for process reliability: incorrect weight specifications, unnecessary rework, and error-prone processes. Therefore, the scale should be selected so that its usable range matches the typical composition of the actual shipments being weighed.

Accuracy Class III is the typical commercial class for non-automatic scales and, therefore, also for many package scales used in commercial settings. In practice, this means that the scale is designed for standard business weighing tasks where weight values must be recorded reliably and traceably. The class describes a legally defined accuracy framework, not an arbitrarily fine display resolution. Whether a scale is suitable for a specific application therefore always depends on how it is designed for the actual shipments. Companies should view Class III as a suitable standard for commercial applications, but should always assess its suitability in the context of the intended process and load range.

The user notification must be submitted within six weeks of putting a new parcel scale subject to calibration into service. The decisive factor, therefore, is the date on which the scale is actually put into use in a context subject to calibration. The competent authority is the calibration authority or the state calibration office in the location where the scale is used. In practice, the notification is often submitted digitally via the respective government portal. Companies should provide complete information on the essential device data and the location of use, and document the submission internally. This requirement is important from an organizational standpoint because it makes proper operation verifiable to the supervisory authority and helps avoid unnecessary follow-up inquiries during subsequent inspections.

In practice, the operator submits an application for re-calibration to the competent state calibration authority or calibration office well in advance of the deadline. An appointment is then scheduled for the inspection—either on-site or at a testing facility, depending on the state. The scale must be in working order, clean, and accessible; suitable test weights or a load-bearing test environment are often required. The inspection covers the scale’s condition, markings, metrological properties, and compliance with permissible error limits. If the package scale passes the inspection, it is re-marked and may continue to be used. If defects are found, it must be repaired and resubmitted for inspection; until then, it may not be used in applications subject to calibration requirements.

For parcel scales with a calibration period of at least one year, the period does not end on a specific day in the middle of the current operating year, but generally only at the end of the calendar year in question. This simplifies matters in practice because companies can better plan their recalibrations from an organizational standpoint. What matters is when the period expires according to the calendar; if this date falls within a specific year, the scale may generally still be used until December 31 of that year. It is therefore important for operators not only to estimate deadlines based on months but also to keep track of the calendar-year expiration dates. This helps prevent downtime, scheduling issues, and unnecessary interruptions in the shipping process.

For scales with a maximum capacity of 3 metric tons or more, a calibration period of 3 years generally applies. This applies in particular to industrial scales and truck scales in this load range. For automatic checkweighers, such as those used in sorting systems, however, the general calibration period of 2 years generally applies, unless a specific exception applies. The legal basis for this is Section 34 of the Measurement Ordinance (MessEV). Important for practical application: For calibration periods of one year or longer, the period ends at the close of the calendar year. Older scales with type approvals issued on or before December 31, 2014, may be subject to different periods in individual cases.

The EU conformity marking on new parcel scales indicates that the legally required conformity assessment has been successfully completed and that the device meets calibration requirements when placed on the market. For operators, this means above all that the scale is not only usable after a subsequent initial calibration, but is already brought to market with the required legal certification. In everyday use, it is important to understand the marking as part of the device’s documentation and identity and to keep it legible. However, the one-time marking is not sufficient for long-term operation; the scale must subsequently be re-inspected within the prescribed timeframe if it is to continue to be used in a manner subject to legal metrological requirements.