Meaning
Precision reference standards manufactured from a glass-ceramic material with a near-zero coefficient of thermal expansion serve as the foundation for high-accuracy dimensional inspection. Utilizing Zerodur master artifacts ensures that calibration measurements are unaffected by temperature fluctuations in the metrology lab or on the factory floor. This material stability is essential when verifying coordinate measuring machines used to check tight-tolerance molded parts.
Using these standards ensures that the measured deviations represent tool wear rather than thermal expansion of the artifact.
Thermal Stability
Most engineering plastics have a high coefficient of thermal expansion, meaning their dimensions change significantly with temperature. Because Zerodur master artifacts maintain their physical dimensions across a wide temperature range, they provide a stable reference that eliminates temperature-induced measurement errors. This allows metrologists to establish a baseline that is independent of ambient air conditions.
Metrology Calibration
The verification of measurement systems must be performed at regular intervals to comply with quality standards. During metrology calibration, the reference artifact is measured to calculate the system’s repeatability and bias. If the artifact were to expand or contract, the resulting calibration would be invalid, which would lead to the rejection of acceptable parts or the acceptance of defective ones.
Maintenance Protocol
Although the material is highly stable, it is brittle and must be handled with extreme care to prevent chipping or scratching. Storing these Zerodur master artifacts in protective cases when not in use is required to maintain their accuracy over time.
