Calibration
The List-Magnetik quality management system is certified according to DIN EN ISO 9001:2015. It calibrates only List-Magnetik-manufactured measuring and testing equipment. All List-Magnetik testing devices are calibrated by our laboratory before delivery.
List-Magnetik is not DAkkS-accredited according to ISO 17025. The most significant difference between a DAkkS calibration and an ISO calibration from a calibration laboratory is the monitoring of the laboratory. The costs for this monitoring are significantly higher than for an ISO calibration. If you require a DAkkS certificate for a magnetic field measuring device, we will forward the device to a partner laboratory. This is not possible for other device categories.
Definitions Relating to Calibration
Calibration (general)
Calibration means that a calibration laboratory compares the display of a measuring device with a reference device, standard, or reference. In short, a calibration laboratory performs a target/actual comparison during calibration. The result of the calibration is documented in the calibration certificate. This certificate contains information about the calibration object/test item, the reference(s), the test setup, the test procedure, and the environmental conditions during calibration. Calibration does not involve any permanent intervention in the measuring device.
ISO calibration
The quality management standard DIN EN ISO 9001 stipulates test equipment management, including regular inspection of the equipment. Regarding the type of calibration: However, there are no specifications regarding the certification of calibration laboratories or the scope of calibration services. DAkkS calibrations unconditionally meet the requirements. For cost reasons, however, ISO calibration is often performed on measuring instruments with little to medium influence on the end product. All ISO calibrations performed in the List-Magnetik calibration laboratory meet the following criteria:
- References must be traceable to national or international standards
- There is a detailed description of the measurement procedure, as well as the applicable standard or guideline
- Documentation of the environmental conditions
- Verify the measurement results using the dual control principle
- The measured values are evaluated against the specified manufacturer tolerances
ISO calibrations from the List-Magnetik calibration laboratory thus meet the requirements of DIN EN ISO 9001.
Traceability
Calibration by a calibration laboratory involves comparison. Sticking with this analogy, traceability is the chain of comparisons. In other words, traceability involves comparing the reference used in one or more stages with a more accurate reference, and so on, until the national standard or similar serves as the final point of comparison at the beginning of the chain.
The scope of calibration services
Calibration includes the precise definition and procedure of the measurement process, a list of the standards or references used, documentation of the environmental conditions in the laboratory, the calibration date, and the technician's name and signature. The calibration laboratory documents all this information on the calibration certificate for each calibration. Thanks to this information, it is possible to trace and repeat a calibration in the laboratory.
How do I choose the right calibration interval?
In some cases, legislators, professional associations, or the VDE specify calibration intervals. However, in most cases, this is the sole responsibility of the operator of the test equipment. This is because only the operator, and not the calibration laboratory, is familiar with all the technical and economic factors. Technical factors include the measuring principle, operating conditions, requirements for the test equipment, historical trend data, frequency of use, and relevance to the quality of the end product. Economic factors include potential recall costs, calibration laboratory or service costs, and downtime costs during calibration.
In practice, a calibration laboratory chooses a compromise between safety and calibration costs based on these factors. However, when making this decision, the operator of a test device must be aware that, if the calibration results are unsatisfactory, all previous measurements up to the last calibration must be questioned, and the operator must accept the consequences. One important detail that is often overlooked is that if the validity date on the most recent calibration certificate for a measuring device is about to expire and the device will no longer be used, the device must be sent to a calibration laboratory for a final calibration before being removed from the company's inventory of test equipment. This ensures that the measurement results since the last calibration are correct.
