– Length Metrology Basics

Techniques and tools used to measure linear dimensions with high accuracy across various manufacturing environments.

• Shop floor measuring instruments: handheld or stand-mounted tools used for quick and direct length measurements on the production floor
  • Micrometers
  • Vernier calipers
  • Height gages
  • Depth gages
• Mechanical comparators: magnify small displacements using mechanical linkages to compare dimensions against standards.
• Electronic comparators: convert displacement into electronic signals for high-resolution measurement.
• Optical projectors: project magnified images of parts onto a screen to compare with dimensional overlays or templates.
• Pneumatic comparators: compares air pressure variations to evaluate dimensional deviations in precision parts.
• Fixed gages (plug and ring gages): Go/No-Go style gauges verify if part dimensions are within tolerance limits.
• Special-purpose gages: custom gages simultaneously check several features or critical dimensions.