Traceability

Measuring instruments for pressure and temperature are used in almost all areas of industrial manufacturing. Due to continuous mechanical, chemical and thermal loading, these instruments age and may therefore not guarantee the correctness of the measured values during the period of time. Through timely calibration, however, the alteration of the measured value can be determined.
In the process of calibration, the displayed value of the measuring instrument is compared with the measuring result of a different measuring device which is known to function correctly and accurately and which itself has been designed to coincide directly or indirectly with a national (or international) reference instrument. In short, to compare measuring results, they need to be ?traceable? to เกจวัดแก๊ส or international standard via a chain of comparative measurements. The calibration hierarchy shown in the picture (using the example of Germany) depicts the traceability of an inspection equipment in an organization up to national standard at the PTB (German national metrology institute).
So as to ensure traceability used, the following points should be observed, among others:
The chain of comparison should not be interrupted.
The measurement uncertainty should be known in each stage of the calibration chain so that the total measurement uncertainty can be calculated. As a rule, a superordinate measuring instrument must have a measurement accuracy three to four times higher.
Each part of the calibration chain should be documented, including the measurement results.
All bodies carrying out a stage in the chain must prove their competence through accreditation.
Calibrations should be repeated at appropriate intervals. The periods depend on the demanded measurement accuracy and the technical requirements
Note
The WIKA calibration laboratory is accredited by the German Accreditation Body (Deutsche Akkreditierungsstelle ? DAkkS) relative to DIN EN ISO / IEC 17025 for the measurands temperature, pressure, DC current, DC voltage and DC resistance. More info on our calibration laboratory or an on-site calibration with the WIKA calibration van can be found on the WIKA website. When you are interested in our services, please feel free to e mail us via e-mail.
Learn more about the differences between factory calibration and traceable calibration in the following video:

Leave a Comment