DAkkS calibrations for scales
Calibrate test weights according to DAkks
What does calibration mean?
Determining and documenting the deviation of a measuring instrument’s readout or the specified value of testing equipment from the true, actual value of the measured variable.
What is the DAkkS?
The abbreviation DAkkS stands for Deutsche Akkreditierungsstelle GmbH. Since 17/12/2009, it has been the successor of the German Calibration Service (DKD) in the field of accreditation (EC Regulation No. 765/2008). There is no difference in metrology between calibration according to DAkkS and the earlier calibration according to DKD.
Why a calibration according to the specifications of the DAkkS?
If certain things are to be measured, scales and testing equipment are required. It is of fundamental importance that the measured values displayed by the scales are also “correct”, because incorrect or inaccurate measurement results can quickly have financial consequences and may result in high costs. Electronic measuring devices should therefore be checked regularly. During this process, they are also calibrated correctly at the same time and adjusted if necessary. In the case of calibration according to the specifications of the DAkkS, the entire procedure and the traceability to the national standard is precisely documented. In this way, an electronic scale, test weight or other measuring device becomes a reliable measuring and testing instrument. As a company with integrated certified quality management (e.g. according to ISO 9000ff, TS 16949, VDA, FDA, GLP, GMP, ...), we are obliged to check our measuring equipment and scales regularly. With an internationally recognised DAkks calibration certificate confirming a test according to DIN EN ISO/IEC 17025:2005, we fulfil this normative requirement.
Who may calibrate according to DAkkS?
If you want a calibration to be not only valid but also recognised, it must be carried out by a calibration laboratory that has been accredited by the DAkkS. These calibration laboratories must provide proof of a valid accreditation certificate from the DAkkS.
graviCAL GmbH meets all of the requirements of the DAkkS and is therefore a DAkkS-accredited calibration laboratory.
Further information can also be found on the website of the German Accreditation Body (DAkkS).
What does traceability mean?
Test standards (weights) that are used in different laboratories need to be in accordance with one another. It’s also important that all weights used for scale testing, adjustment and calibration are traceable to the primary kilogram (or, since May 2019, has been derived from the Planckian natural constant), or a national standard.
Due to this traceability to a generally recognised reference quantity, such as the primary kilogram, measurement results are placed on a generally recognised foundation as the basis for the accuracy of their results – a fundamental prerequisite for the reliability and comparability of results.
The comparative measurements for traceability are carried out in national metrological institutes, accredited calibration laboratories and verification authorities. Each connection (traceability) is documented by a test or calibration certificate, in which the determined deviation from the nominal value and the measurement uncertainty are stated.
The differences between factory calibration, calibration (according to DAkkS) and official verification
| Factory calibration | Calibration (according to DAkkS) | Official verification |
| Factory calibration is not regulated by law. | Calibration according to DAkkS specifications is not legally regulated. | Official verification is regulated by law. |
| Reason for a factory calibration Outliers” in devices or equipment that have been reactivated after a longer period of time, general check-up. “Does my equipment still function properly?” |
Reson for a calibration If the test weight or scale is used within a quality management process, a calibration according to DAkkS specifications should be carried out beforehand. |
Reason for an official verification As soon as one participates in a so-called "custody transfer", it is required by law. This includes for instance the sale of goods by weight, the calculation of fees by weight or the manufacture or inspection of pre-packaging etc. Further details can be found in the Weights and Measures Act. |
| What can be factory-calibrated? Testing equipment and measuring instruments that are not subject to a calibration routine according to DAkkS and are not subject to legal metrology. |
What can be calibrated? All error-free testing equipment can be calibrated according to DAkkS. |
What can be officially verified? Only “calibratable” scales with type approval and test weights that meet the requirements of the OIML (Organisation Internationale de Métrologie Légale) can be officially verified. |
| Procedure Is not fixed. Is carried out for instance analogously to the conformity assessment (official verification). The measurement deviations are indicated using calibrated weights. A factory calibration certificate is issued after the calibration has been carried out. |
Procedure A laboratory accredited by the DAkkS tests the testing equipment for correctness by tracing back to internationally recognised standards. Such calibration may only be carried out by highly qualified staff who have presented themselves to the DAkkS certification body. A calibration certificate is then issued. |
Procedure Scales and weights are checked for calibration error limits (maximum permissible errors). This is carried out by the manufacturer (only for manufacturer’s verification) and the Weights and Measures Office (within the legally prescribed intervals). A stamp certifies that the measuring instrument has met the requirements at the time of testing and that it remains “correct” within the recalibration period if it is handled in accordance with the rules of technology. |
| Validity The DIN EN ISO 9001:2015 (7.1.5.2)leaves the choice of suitable testing methods to the user. As a rule, a factory calibration is sufficient if traceable testing equipment has been used. |
Validity International recognition is ensured by multilateral mutual recognition agreements between EA (European Cooperation for Accreditation) and ILAC (International Laboratory Accreditation Cooperation). In Germany, the German Accreditation Body “DAkkS”, formerly “DKD”, watches over this. |
Validity For the European Union, a declaration of conformity with CE marking is regarded as “initial verification”. Only subsequent verification and national declarations of conformity are nationally recognised. |
| How often? A factory calibration can be carried out as often as the owner of the measuring instruments and testing equipment deems appropriate. According to 9001:2015, the user determines the cycle after use. |
How often? The owner of the measuring instruments and testing equipment is responsible for compliance with the respective recommended periodic recalibration periods. |
How often? By law, the subsequent verification periods for testing equipment and measuring instruments are defined in national specifications. |