– 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.