Precision Measurement Glossary
Key terms and definitions in metrology and precision gauging
C
Class ZZ
A pin gauge accuracy class with ±0.001mm tolerance, the most common industrial standard for general quality control.
Calibration Certificate
A document showing the actual measured dimensions of a gauge, traceable to national or international measurement standards.
Ceramic Pin Gauge
A pin gauge made from advanced ceramic material, offering non-magnetic properties, corrosion resistance, and exceptional dimensional stability.
Ceramic Gauge Block
A gauge block made from advanced ceramic material, offering non-magnetic properties, corrosion resistance, and exceptional dimensional stability over temperature changes.
G
Go/No-Go Gauge
A two-limit inspection tool where the go end checks the minimum acceptable dimension and the no-go end checks the maximum.
Gauge Block
A precision rectangular block of steel or ceramic with two ultra-flat parallel faces, used as a length standard for calibration and measurement. Available in various grades and sets.
Grade 0
The highest accuracy grade for gauge blocks, with ±0.12μm tolerance, used in calibration laboratories and reference standards.
Grade 1
A medium accuracy grade for gauge blocks, with ±0.20μm tolerance, suitable for inspection rooms and precision tool setup.
H
HRC
Rockwell Hardness Scale C, used to measure the hardness of hardened steel. CEGA steel gauges are HRC 60-62.
M
Metrology
The scientific study of measurement, including precision measuring tools and calibration standards.
P
Pin Gauge
A precision cylindrical measuring tool used to check hole diameters and slot widths. Available in steel, ceramic, and carbide materials.
T
Tolerance
The permissible variation in a dimension, expressed as upper and lower limits from the nominal size.
W
Wringing
The process of sliding two ultra-flat gauge block surfaces together to create a molecular bond, allowing multiple blocks to be combined into exact lengths.