Calibration of measuring instruments

The calibration of measuring instruments is a critical part of quality assurance, ensuring that measuring devices operate accurately and reliably. Calibration checks the condition and measurement accuracy of measuring instruments, which in turn enables the production of high-quality products and services and compliance with regulatory and standard requirements.

Importance of the Calibration Process

Calibration is particularly important for the following reasons:

• Ensuring Measurement Accuracy: Calibration helps ensure that measuring instruments provide accurate and repeatable measurement results. This is important in production processes, for example, where a small measurement error can lead to significant quality degradation.
• Meeting Quality Requirements: In many fields, such as healthcare, aviation, and electronics, the accuracy of measuring instruments is critical. Calibration helps meet the strict quality requirements of these fields.
• Cost Savings: Accurate calibration can reduce product rejections, rework, and customer complaints caused by erroneous measurements, saving time and money.
• Regulatory Compliance: Many standards and regulations require that measuring instruments are calibrated regularly. Compliance with these requirements is essential, among other things, for market access of products.

Steps in the Calibration Process

Preparation:

• Identify the measuring instruments to be calibrated and their intended use.
  Select appropriate calibration methods and necessary standards.
  Pre-check:
• Check the condition of the measuring instrument and its suitability for calibration.
  Document the identification details of the measuring instrument, such as model, serial number, and owner.
  Measurements:
• Perform measurements using precise standards or reference instruments.
  Compare the values indicated by the measuring instrument with reference values.

Analysis of Deviations:

• Calculate deviations between the measuring instrument and standard values.
  Record and analyze deviations for acceptability.
  Correction and Adjustment:

If excessive deviations are found in the measuring instrument, it is adjusted or corrected to meet the standard.
Reporting:

• Document calibration results accurately.
• The report includes all measurements performed, standards used, and any adjustments made.

Follow-up and Recalibration:

• Determine when the measuring instrument should be recalibrated.
• The validity period of the calibration is usually indicated by a color-coded label attached to the measuring instrument.

Calibration Labels and Traceability

The validity of the calibration and the next calibration date are often indicated by a color-coded label attached to the measuring instrument. For example:

• Color-coded label: The color on the label indicates the next calibration year, and the number indicates the month.
• Red markers: Instruments that need to be calibrated before use are often marked with a red color-coded label and a zero number.
• The calibration must be traceable to national or international standards to ensure the comparability and reliability of measurement results. This traceability is an essential part of a quality management system.

ISO 9001 and Measurement Instrument Calibration

ISO 9001 is an international standard that defines the requirements for a quality management system. It covers several areas of an organization's operations and emphasizes continuous improvement and customer satisfaction. As part of a quality management system, ISO 9001 requires that:

• Measuring instruments must be calibrated regularly or their accuracy verified before use.
• Calibration must be done by comparing the results of the measuring instrument to standards that are traceable to international or national regulations.
• The results and deviations of calibrations must be reported and documented properly.
• Properly performed calibration not only improves product quality but also strengthens the organization's ability to meet stringent regulatory and customer requirements, which is one of the main objectives of the ISO 9001 standard.

Benefits of Calibration

Proper calibration of measuring instruments brings several advantages, such as:

• Accuracy and Reliability: Ensures that measuring instruments provide accurate and reliable results.
• Quality Improvement: Enhances the quality of the product and process by ensuring that measurements are accurate.
• Regulatory Compliance: Helps meet statutory and industry requirements.
• Cost Management: Reduces costs associated with incorrect measurements.

Summary

The calibration of measuring instruments is a central part of quality assurance, ensuring the accuracy and reliability of measuring devices by comparing their results to a known standard. Calibration includes preparation, pre-checking, performing measurements, analyzing deviations, necessary adjustments, reporting results, and determining the next calibration time. The ISO 9001 standard requires regular calibration and accuracy verification of measuring instruments to ensure that products and services meet the required quality standards. Calibration reduces measurement errors and faulty products, improving quality and saving costs, and ensures compliance with regulatory and standard requirements. Generally, the validity of calibration is marked on the measuring instrument with a color-coded label, ensuring the traceability of measurement results to national and international standards.