Measuring plates made of granite are aids in quality assurance for measuring production parts. Granite plates are used across all industries for measuring and testing equipment wherever precision needs to be repeatable.
The measuring plate as an aid in quality assurance for measuring production parts
The flatness of the surface is decisive
Measuring plates made of hard rock as well as hard rock standards – such as test rulers and test angles – are proven in precision machining. These are the oldest hard rock applications in precision machine and plant construction. Measuring plates are required as an aid in quality assurance for measuring production parts. The flatness of the surface is of great importance, serving as a reference surface for the use of various measuring devices and instruments. This is the only way to make measured values repeatable and comparable. The tolerances for the flatness of the surface are classified in DIN 876. There are several quality classes, e.g. the DIN 876/0 marking stands for quality class 0.
Machining of granite measuring plates: precision work
The high surface quality is achieved by grinding and subsequent manual lapping of the granite measuring plate. Depending on the quality class, several measuring and lapping processes are necessary. Flatness is determined using electronic inclinometers before being documented as a test report or calibration certificate. Important for the use of granite measuring plates: an intrinsically stable installation on the besel's points. In order to guarantee the precision of the granite plates permanently, the hard rock measuring plates must be calibrated at regular inspection intervals.
Measured values must be repeatable and comparable.
Increasing demands on measuring plates made of hard rock
Smaller measuring and control plates made of granite (up to approx. L=2,000 mm) are sold by tool dealers via an online catalogue. They mainly originate in Asia. Often only the calibration of the measuring plates takes place in Europe. Custom-made products are becoming increasingly important. These custom-made granite measuring plates are the result of ever increasing demands on product quality and process reliability. Decisive factors are:
- Sizes over 2,000 mm
- Available space
- Useful total weight
- Constructive adaptations such as drilling patterns, reference edges
- Process-related adaptations, e.g. guides, measuring systems
Why do we rely on granite when measuring technology is all about precision?
These four properties make granite the ideal material for measurement technology machines.
