Precision measuring equipment made of hard stone

Granite is used for measuring standards such as angle standards, measuring angles or test frames because the natural hard stone offers outstanding properties. Granite is dimensionally stable, wear-resistant, temperature-resistant and magnet-free - ideal properties for high-precision measuring tasks.

For its precision measuring equipment, PLANOLITH uses selected hard stones from Europe, Asia and Africa with high density, fine grain structure and minimal thermal expansion, which are particularly suitable for precision applications.

Compared to steel, granite gauges offer high and long-term dimensional stability as well as very low thermal expansion, so that they remain dimensionally stable even with temperature fluctuations. They are also wear-resistant, corrosion-free and non-magnetizable, which makes them ideal for precise measuring and testing tasks.

Compared to ceramic, granite is less brittle and less sensitive to punctual loads. Thanks to the finest grinding and lapping processes, granite measuring equipment achieves the highest flatness and accuracy classes in accordance with DIN and ISO standards.

Measuring standards and geometric standards made of granite are manufactured according to defined accuracy classes that specify the permissible flatness and dimensional accuracy. DIN 876 is decisive for measuring plates and comparable measuring surfaces. It distinguishes between the accuracy classes 3, 2, 1, 0, 00 and 000. The higher the class, the more precise the flatness. Class 000 offers the highest precision and is ideal for laboratory, calibration and high-precision measuring tasks.

Internationally, accuracy is regulated by ISO 8512. This standard defines similar tolerance ranges for hard stone measuring surfaces and ensures comparability in global use.

Precision measuring instruments made of granite should always be handled carefully and properly in order to maintain their accuracy in the long term. It is important to protect them from knocks and impacts, as even minor damage can affect the measuring surfaces. Likewise, strong temperature changes should be avoided: Although granite is very temperature-stable, it needs some time to adjust so that the measuring surfaces do not warp.

Cleanliness also plays a major role. Dust, oil or chips can falsify measurement results and damage the surfaces. Measuring equipment should therefore be cleaned regularly and carefully wiped down before use.

Correct storage on suitable supports or in protective packaging is also recommended, as is regular inspection and calibration in accordance with DIN and ISO specifications.

Granite measuring equipment should be transported in sturdy wooden crates or transport boxes with precisely fitting foam inserts to protect it from shocks and prevent it from slipping. It is important to avoid impact and shock loads, as even minor damage can affect the measuring accuracy.

Granite measuring standards are always placed on a clean, flat measuring plate and then aligned with their defined reference surfaces. Depending on the component, they are either placed flat, aligned on stops or fixed with light pressure against a reference edge in order to achieve a repeatable position.

The actual test is then carried out using suitable standards or measuring systems - e.g. dial gauges, autocollimators or precision standards - in accordance with the relevant DIN and ISO standards. It is important that the component and measuring room are temperature-controlled so that precise and reproducible measurement results can be achieved.

Heat leads to changes in length. Although natural hard stone reacts very little, it still needs some time to adapt. Therefore, temperature differences between the measuring equipment, environment and workpiece can lead to measurement deviations.

Yes, granite measuring agents can be used directly on granite measuring plates. Make sure that the surfaces are free of dirt to avoid scratches. Our cleaning and care products are ideal for this purpose.

Precision measuring instruments made of granite should always be stored on their intended support points or in suitable holders so that no uneven stresses occur. A dust-protected, dry environment with temperatures that are as constant as possible is ideal for maintaining dimensional stability and evenness. If not in use for a longer period of time, we recommend covering or storing in the original packaging.

Granite measuring standards should be cleaned and maintained regularly and calibrated periodically. Careful handling of measuring and testing equipment is of course a general prerequisite.

Measuring scales made of granite should be cleaned with a lint-free, soft cloth to avoid scratching the finely machined measuring surfaces. White spirit or a comparable mild agent is suitable for removing oil or dirt residues. Aggressive solvents, oils or cleaning agents containing silicone should be avoided as they can leave residues or damage the surface. The surfaces should be dust-free and dry before each measurement.

As the tolerances of granite measuring standards are in the µm range, damage is often not visually recognizable. Regular calibration at annual intervals is therefore strongly recommended.

Measuring standards such as measuring angles, angle standards, measuring beams, measuring columns, test frames or calibration cubes should generally be calibrated every 1-2 years. The intervals for calibration depend on the use and operating conditions of the measuring equipment as well as the internal requirements for test equipment monitoring.

Yes, PLANOLITH offers an independent repair and calibration service for all makes of granite measuring equipment. We can rework/calibrate your existing granite measuring standards here in our climate-controlled calibration laboratory or on your premises.

DAkkS calibration of measuring standards means that their deviations from national or international standards are determined and documented by a laboratory accredited by the German Accreditation Body (DAkkS) (air-conditioned and accredited calibration laboratory for the measurement of flatness at PLANOLITH) in accordance with the ISO/IEC 17025 standard. This guarantees the highest possible measurement accuracy, international recognition and traceability of the measurement results.

• Highest metrological safety
• International recognition
• Traceable documentation
• Maximum accuracy

A new purchase of precision measuring equipment made of granite is necessary if the item is so badly damaged that repair is not economically viable. With our many years of experience in calibration services, we will be happy to help you weigh up the options. Get in touch with us to assess this on a case-by-case basis.