Vernier calipers and micrometers measure dimensions precisely.
Steel rules, vernier and digital calipers (0.02 mm), micrometers (0.01 mm), dial gauges, height gauges, gauge blocks, feeler gauges and go/no-go gauges measure dimensions. Choose instruments with resolution about 10× finer than the tolerance. Care: clean, zero, apply consistent force.
A micrometer measures a 20.00 mm shaft within ±0.01 mm.
Precise measurement is the foundation of quality, because parts can only be checked against limits if the measurement is reliable.
Vernier calipers and micrometers measure dimensions precisely.
Precise measurement is the foundation of quality, because parts can only be checked against limits if the measurement is reliable.
Outside, inside and depth dimensions to a resolution of about 0.02 mm or 0.001 in, using a sliding scale.
Accuracy is closeness to the true value, while precision is how repeatable the readings are, and a good measurement needs both.
Typical applications include measuring a shaft diameter to check it against its tolerance, checking the depth of a slot with a depth gauge and confirming the thickness of a sheet before bending.
Study "Basic workshop tools" first (topic 8 of 102 in Manufacturing, Robotics & Systems). It covers the groundwork this topic builds on.
Least count. Parallax error. Calibration.
A micrometer measures a 20.00 mm shaft within ±0.01 mm.
The next topic is "Limits, fits and tolerances", which builds directly on this one.
It is classed as Beginner in Manufacturing, Robotics & Systems (topic 9 of 102). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.