Precision Metrology as a Diagnostic Science
Metrology is the science of measurement. At GPI, precision metrology evaluates aeronautical Mylar technical data to determine how closely it conforms to defined geometric targets such as gridlines, trammel points, and geometric features.
Our objective is the restoration and preservation of Uniform Geometric Integrity.
Low Accuracy / Low Precision
Understanding Accuracy and Precision
Accuracy and precision are not synonymous.
Accuracy is achieved by first quantifying error. Error is expressed as either linear or random distortion.
Precision is the ability to repeatedly produce results within a defined tolerance, such as ±.005”.
Low Accuracy / High Precision
High Accuracy / High Precision
Types of Geometric Error
Types of Geometric Distortion in Technical Data
A - Original
Accurate and dimensionally stable.
B - Proportional Error
C - Linear Non-Proportional Error
Uniform scaling distortion across the entire sheet. It grows larger.
Unequal distortion along one or more axes.
D - Non-Linear Non-Proportional Error
E - Random Distortion
Multi-axis geometric distortion.
Multi-axis geometric distortion.
Why Precision Metrology Matters
Measurement between trammel points is foundational to dimensional verification.
However, point-to-point analysis alone cannot determine the full geometric condition of aeronautical technical data.
Precision metrology evaluates geometry on the full sheet, identifying distortion and restoring geometric integrity before duplication or digitization proceeds.