WCA March 2017

Technology news

Self-calibration of measuring units

This includes, for example, test equipment that is used as reference during the production process. Zumbach adheres to different standards and guidelines of quality assurance. Zumbach measuring units are calibrated using reference standards which were certified by the Swiss federal office for metrology (www.metas.ch) or by accredited laboratories. Each unit is supplied with a detailed calibration protocol. A regular check for measuring errors along with the corresponding protocol can be carried out according to customer requirements. The regularity of these calibrations is dependent on the customer-specific requirements (internal regulations). The company recommends a check of accuracy every 12 to 24 months. All the measuring heads of the ODAC ® series have a self-calibration function (Patent DE3111356) which makes a subsequent, regular calibration superfluous, except when exchanging components. All the relevant parameters for accuracy are continuously monitored by the measuring system and automatically compensated when required. Zumbach Electronic AG – Switzerland Website : www.zumbach.com

CALIBRATION measurement technology means establishing the measurement deviations on the measuring unit. During the calibration no technical intervention occurs at the measuring instrument, as opposed to adjusting where a measuring instrument is set or adapted to keep the measurement errors as small as possible or that the number of measurement errors do not exceed the error limits. The official calibration of a measuring unit is carried out according to the rules and regulations of the examining authority, and the unit is marked with the respective stamp. The examining authority establishes whether the measuring unit fulfils the respective prerequisites. The validity of a calibration period follows practical requirements such as manufacturer’s information, requirements of quality standards or company internal and customer-specific regulations, rather than an official calibration with a fixed time period validity for use. In order to be able to compare results of measurement, it must be possible to ‘feed back’ information via a chain of comparison measurements to a national or international master. For this purpose, the display of the measuring unit in use or the material representation must be compared with the masters in one or more stages. in

On each of these stages a calibration is carried out with a master which has been previously calibrated with a higher-level master. According to the ranking of the master – of consumption or factory standards via reference masters up to national standards – there is a calibration hierarchy of points to be carried out. Different standards, regulations and guidelines are valid for the expert carrying out of calibrations. Standards and regulations, such as the ISO 9000 series, are becoming more important for quality assurance in all industrial nations. Then it may be explicitly required to calibrate all test equipment that directly or indirectly influences the quality of the product. diameter measuring gauge with reference calibration standards ❍ Typical ODAC ® laser

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Wire & Cable ASIA – March/April 2017