The Long History from Accurate Measurements to Dimensional Calibration
Dimensional calibration has its roots in accurate measurements.
The concept of accurate measurement has a long history dating back to the early Mesopotamian and Egyptian times when the measurements were based on body parts such as fingers, arm spans, foot size, and palm distances. Eventually, the Greeks and Romans adopted and standardized the system of measurement into feet and meters. These measurements were used to define the dimensions of buildings and fields legally. Carpenters and surveyors were the first craft persons to apply the standards of measurement.
Over time, the field of measurement evolved in modern day to include sophisticated instruments such as machine vision systems, laser trackers or optical comparators. As the measurement tools became more and more precise, there grew a need to validate the accuracy and repeatability of these instruments of measurements.
What is Dimensional Calibration?
Accurate measurements depend on the accuracy of the tools used for measurement. Consider the precision that is required in the manufacturing of plane parts. In all manufacturing plants, sophisticated tools are used to measure products.
For measuring length for exact circumstances, the device that is used for taking measurement needs to be verified for accuracy on an ongoing basis. This is at the core of dimensional calibration. The measuring tools used to manufacture parts of a fuselage, for example, require verification of their accuracy.
Labs can determine the accuracy of length measurement tools of instruments such as calipers, gauges, micrometers and tape measures as well as the high-tech optics based scales and comparators. Through the calibration of your devices, your risk and inaccurate measurements will be reduced. The parts are measured to a standard of known or assigned correctness and this figure can be corrected, thereby ensuring accurate measurement in your operation.
Industries such as oil and gas, chemicals, aerospace, nuclear, manufacturing and automotive all require accurate measurements for their specific equipment for several different purposes such monitoring of the equipment for accuracy, as part of compliance for government regulation, and for scheduling replacement parts of components in the industry. Dimensional calibration inspections can take place in-house or at lab facilities.
CMM Dimensional Testing
The CMM machine (coordinate measurement machine) is a device that measures objects in three dimensions. It is especially suited for measuring complex parts, such as the blades of a turbine or engine shafts. Components can be measured one at a time or in combination.
Why is Accurate Measurement Important? Expectations of Consumers
Accurate measurement is a fundamental part of translating the design of parts of a product into commercial reality. The customer expects that throughout the manufacturing process multiple products will be identical so that any replacement parts that will be needed will fit into the product.
Ensuring accurate measurements throughout the manufacturing process makes this a reality. Consider the case of automobiles. It is a fact that replacement parts will be required over the lifetime of the car. So, the replacement fuel injection pump must be able to be placed into a specific model of a vehicle without any doubt for whether it will fit. Dimensional calibration provides the means for assuring the accuracy of the equipment in the production line.
How is this accuracy accomplished? – statistical process control (SPC). Statistics are used to monitor the industrial process. To simplify, the method may involve measuring every tenth item off the production line.
After the measurement is taken, a recording of the dimension of that product is saved. Over time the measurements might reveal a deviation from the exact size. The manufacturer then can take steps to correct this deviation to maintain the measurements of the part within upper and lower tolerances.
With a dedicated measuring scheme and accurate equipment, the manufacturer has confidence that his product will meet consumer expectations as well as government standards.
Finding the Best Third Party Company to Test your Measurement Tools
You can expect some fundamental requirements for professional organizations that will perform dimensional calibration of your measurement tools. The third party company needs to follow excellent measurement standards while complying with government regulations and best practices.
The following six principles to good measurement are recognized across the world.
- “The Right Measurements: Measurements should only be made to satisfy agreed and well- specified requirements.
- The Right Tools: Measurements should be made using equipment and methods that have been demonstrated to be fit for purpose.
- The Right People: Measurement staff should be competent, properly qualified and well informed.
- Regular Review: There should be both an internal and independent assessment of the technical performance of all measurement facilities and procedures.
- Demonstrable Consistency: Measurements made in one location should be consistent with those made elsewhere.
- The Right Procedures: Well-defined procedures consistent with national or international standards should be in place for all measurements.”
Government Regulations for Australia
Four national organizations form Australia’s well-developed standards and conformance infrastructure, according to the government website. In March 2010 these four organizations established a new body, the Technical Infrastructure Alliance, which runs joint projects to promote greater efficiency and performance in quality standards. Accredited labs that test instruments for accuracy follow their recommendations.
The Value of Third Party Inspections
The range of inspections at the independent labs covers FAIRS (First Article Inspections), Visual Inspections and Final Inspections. This comprehensive inspection routine will keep your system compliant with government regulations, monitor the health of your components and aid in predicting when a failure might occur. With the availability of records online, you can keep an accurate view of the status of your machinery to control costs while planning a replacement schedule. Note that the confidentiality of your data should be a crucial aspect of the entire system.
Since dimensional calibration provides reliable accuracy and repeatability in any operation, it is an essential part of the process used by many industries.