Measuring
The significance of measuring instruments in ensuring the quality of machined products is undeniable. Effective and precise measurement not only guarantees product quality but also saves time and resources in production processes. The accuracy and reliability of measuring instruments used in the dimensioning and quality assurance of machined parts are crucial.
The dimensioning of machined products requires precision and reliable measuring instruments. Vernier calipers, micrometers, dial indicators, and surface roughness testers are all cornerstones of quality and accurate measurements in the machining industry. These instruments are used to make important quality assurance decisions that directly impact the final quality of products.
The vernier caliper is one of the most common and versatile measuring tools used for external, internal dimensions, and depths. The use of this "machinist's multi-tool" is guided by the SFS-EN 22768-1 standard, which defines general tolerance dimensions and permissible dimensional deviations. The digital age has also brought modern technology, such as digital displays and wireless data transmission, to the use of vernier calipers, improving the reliability of measurement results and ease of handling.
With a micrometer, even more precise measurements can be achieved when tolerances compliant with the ISO tolerance system SFS-EN ISO 286 standard are needed. Micrometers specialize in taking measurements from different parts, such as external and internal surfaces, and specialized areas like thread diameter or gear tooth gaps. Modern micrometers often include advanced functions that combine accuracy and user convenience in measurements.
The surface roughness tester is also an essential tool for determining the surface quality of a machined part. The surface roughness of a part affects not only its aesthetic properties but also its sliding characteristics and fatigue resistance. Therefore, measuring surface roughness is an important part of the quality assurance process, ensuring that the machined part meets the set requirements and that unnecessary over-quality, which can be costly, does not occur in production.
To ensure the reliability of measurements, it is absolutely crucial that the measuring instruments in use are properly maintained and calibrated. Measurement uncertainty, which is the uncertainty regarding how closely a measurement result approximates the true value, affects all measurements. Addressing measurement uncertainty in measurement results is thus an essential part of both quality assurance and ensuring the reliability of measurement results.
The selection, maintenance, and calibration of measuring instruments are critical processes that require attention and expertise. By selecting high-quality measuring instruments and maintaining them well and regularly calibrating them, the quality and reliability of measured products can be significantly improved. Additionally, recognizing and accounting for measurement uncertainty in reporting measurement results is essential for improving the reliability of measurement data.
Every measuring instrument, regardless of its size or purpose, wears out over time. This wear can be so minimal that it is not visible to the naked eye, yet even small deviations can lead to significant errors in measurement results. For this reason, regular calibration of measuring instruments is necessary. Calibration checks the condition of the device and its measurement capability, comparing obtained results to accepted standards. If results deviate from accepted values, the measuring instrument should be recalibrated or removed from use.
A common practice is that a measuring instrument should be calibrated when the last usage month indicated on the calibration label is reached or if there is any doubt about the instrument's condition. It's important to remember that a measuring instrument should not be used if it does not have a valid calibration sticker or if its calibration period has expired.
ISO 9001 is an international standard for quality management systems published by the International Organization for Standardization (ISO). The standard requires that all measuring instruments used for monitoring and measurement must be either calibrated or verified to meet set requirements. The calibration process must be based on comparisons to measurement standards traceable to international or national standards. Management of measuring instruments in compliance with ISO 9001 demonstrates an organization's commitment to precision and quality, which strengthens trust among customers and stakeholders.
The calibration of measuring devices is usually indicated by a color-coded sticker. The color of the sticker indicates the next calibration year, while the sticker's number denotes the calibration month. For example, a red color-coded sticker with the number zero means that the measuring instrument should not be used before recalibration. These stickers provide an easy and quick way to ensure that the measuring instruments in use are up-to-date and reliable.
Proper and regular calibration is critically important for quality assurance. It not only reduces the risk of measurement errors but also lowers manufacturing costs by improving process efficiency. Additionally, proper maintenance and storage of measuring instruments help ensure their long service life and accuracy. Operating in accordance with ISO 9001 standard demonstrates a commitment to high-quality management, creating trust among customers and stakeholders. Considering all these aspects, it's clear that the calibration of measuring instruments is an essential part of the operations of any organization committed to quality.
