In industrial production, the use of precision measuring tools-such as vernier calipers and micrometers-is essential to ensure the dimensional accuracy of equipment parts and workpieces. Precisely because of their high precision, they must be used according to standardized and proper operating procedures. Furthermore, the maintenance and care of these tools are subject to strict requirements; improper handling can compromise their accuracy and reliability, so users must master the correct methods.
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Requirements for the Proper Use of Precision Measuring Tools
Not all components are suitable for measurement with precision tools. For instance, precision tools must never be used on rough forgings or castings, or on surfaces containing abrasive materials (such as emery/carborundum). Doing so can easily wear down the tool's measuring surfaces and impair its accuracy.
Before taking a measurement, inspect both the measuring surfaces of the tool and the surfaces of the part to be measured to ensure they are clean. Foreign matter can affect measurement accuracy, so any such debris must be wiped away before proceeding.
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Temperature is a critical factor affecting measurement results due to thermal expansion and contraction. To ensure accuracy, the temperatures of both the part and the measuring tool must be equalized. Ideally, measurements should be taken at a standard room temperature of approximately 20°C. When storing precision tools, avoid exposing them to direct sunlight or placing them too close to heat sources, as heat-induced deformation can degrade their accuracy.
When measuring parts on a machine tool, never take measurements while the part is in motion; wait until the part has come to a complete stop. Measuring while the part is moving not only compromises accuracy but also causes premature wear on the tool's measuring surfaces-leading to a loss of precision-and poses a risk of safety accidents.
Precision measuring tools are intended solely for measurement and must never be used as substitutes for other tools. Tasks such as scribing lines, hammering, prying parts, or clearing away chips and waste fluids require specialized tools; one should not use a precision measuring tool simply for the sake of convenience. Additionally, carelessly waving or spinning the tool in one's hand is improper practice and can damage its accuracy. Image
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Proper Maintenance and Care of Precision Measuring Tools
If any irregularities are observed during use-such as surface unevenness, burrs, or rust spots, or issues like inaccurate graduations, a bent or deformed body, or stiff movement-the user must not attempt to disassemble or repair the tool themselves. Furthermore, the use of crude methods involving hammers, files, or sandpaper is strictly prohibited. Such actions will not fix the problem but will instead exacerbate measurement errors.
If such issues arise, the correct course of action is to immediately send the tool to a metrology station for inspection and repair. It should only be put back into service after it has been serviced and its accuracy verified.
During use, never pile precision measuring tools together with other tools-such as cutting tools, hammers, or files-to avoid accidental damage. Do not place precision measuring tools on machine tools; the significant vibrations generated during machine operation could cause the tools to fall and sustain damage. Whether in storage or during breaks in use, precision measuring tools should be laid flat in their dedicated cases to prevent damage. Additionally, proximity to magnetic fields can magnetize the tools, interfering with measurement accuracy. Therefore, they must be stored away from magnetic sources, such as the magnetic chucks of grinding machines.
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After use, the measuring tool should be wiped clean promptly. Unless the tool is made of stainless steel or features a protective coating, the surface of standard metal measuring tools should be coated with a layer of anti-rust oil; they should then be placed in their dedicated cases and stored in a dry environment to prevent rusting.
Precision measuring tools require periodic verification and maintenance, even if they have not been used for an extended period. Tools that see frequent use must be regularly sent to a metrology station for servicing and accuracy verification to ensure they consistently meet required precision standards.
