What is calibration and why is it necessary in industrial practice?

Calibration covers a wide range of instruments and equipment. Calibration is possible, for example:

• electrical measuring instruments - multimeters, oscilloscopes, insulation resistance meters, calibrators, clamp-on ammeters, etc.
• pressure and temperature sensors - used in industry, energy and research
• mass and length gauges - scales, calipers, micrometers
• instruments for measuring humidity, pH, speed, force, sound or light
• analytical and laboratory instruments such as spectrophotometers or chromatographs

In each area, instruments are exposed to a variety of influences that can affect their accuracy - mechanical wear, temperature changes, humidity, vibration and ageing of electronic components. Regular calibration is therefore essential to maintain the quality of the measurements.

From a metrological point of view, the following types of calibrations are distinguished:

1. Accredited calibration
   This is carried out in an accredited laboratory. The result is a calibration certificate with the stamp of the laboratory approved by the accreditation authority (CIA in the Czech Republic). An example of an extension of the procedures is calibration according to EN ISO/IEC 17025. This type of calibration is required, for example, in the automotive, aerospace and pharmaceutical industries or in quality audits (ISO 9001, IATF 16949, etc.).
2. Internal or non-accredited calibration
   Performed in accordance with internal company regulations or customer requirements. May be sufficient where accreditation is not required but documentation and measurement continuity is still required.
3. Production calibration (output check)
   This is often the non-accredited calibration referred to in point 2, sometimes referred to as an output check, which is not a calibration in the true sense of the word. An exit check is carried out by the manufacturer of the equipment before it is placed on the market. It is not intended for long-term validation of accuracy, but rather for verification of functionality.

The period of validity of the calibration is not fixed by law, but is based on the metrological rules and requirements of the specific application. The usual calibration interval for electronic instruments is 12 months, but can be shorter (e.g. 6 months) or longer, depending on:

• the type of instrument and its sensitivity,
• frequency of use,
• the environment in which it operates (humidity, dust, vibration),
• customer requirements or quality standards

It is recommended that each organisation should have its own calibration plan based on a risk analysis and the importance of the measured variables and included in the quality manual.

The calibration interval can be extended if you implement processes internally to verify instrument parameters.

We provide calibration of instruments for measuring electrical quantities, especially the following instruments:

• EMC measuring instruments
• digital multimeters
• oscilloscopes and signal generators
• RLC meters and wattmeters
• insulation resistance meters

Calibration uses traceable standards and accurate reference instruments. Of course, a calibration certificate is issued with the measured values and measurement uncertainties.

Calibration is essential to maintain the quality, safety and credibility of the entire measurement chain from the metrology laboratory to the final product. In many industries, it is not just a recommendation but a direct obligation arising from legislation, standards or contractual requirements. Regular calibration will prevent incorrect results, complaints and unnecessary costs.

Not sure how to choose the right calibration? Contact us - we'll be happy to advise and provide everything you need from A to Z.