What are the equipments for linear measurement?

Answer 1

The answer depends on how large the object is and how accurate a measurement is required. They can be:

• an odometer (for hundreds of metres with an accuracy of a meter),
• a tape measure (up to 10 metres, with an accuracy of a few centimetres),
• an optical (laser) range finder (up to 30 metres, accuracy of a centimetre),
• vernier callipers (a few cm to an accuracy of 0.1 mm),
• micrometer (a few cm to an accuracy of 0.01 mm)
• optical, electron, scanning tunnelling and
• atomic force microscopes, that are accurate enough to "measure" individual atoms