Linear measurement refers to the measurement of a straight distance between two points, usually, this is a dimensional reference such as length, height or width of an object.
Measurements are usually taken in a standard unit format that is either in metric or imperial units. The imperial system uses inches, feet, and yards. Whereas the metric system uses millimetres, centimetres and meters.
There are a number of different instruments that are used for linear measuring. They can be classified into two methods of measuring, direct and indirect. Some instruments are can be further defined as graduated instruments as they have a linear scale on them used to take the measurement. Tools can be selected based on the application, the size of the distance or object being measured and the levels of precision required. Some popular types of products include :