Gage

Any instrument or device used for obtaining measurements.

Examples include:

·    Ruler - measures the length of an object

·    Caliper - also used to measure length, but generally much more precisely than a ruler

·    Depth gage - measures depth of holes, cavities or other component features

·    Snap gage - measures diameter or thickness

·    Go/no-go gage - measures a manufactured item and determines whether it meets dimensional tolerances. It is an attribute gage because a part is rated as good or bad (pass or fail); it is commonly used in production because measurements can be made very quickly.

Selecting the appropriate gage will depend on your application - what you want to measure and how you want to use the data. If you simply want to separate good parts from bad ones, then fixed-size go/no-go gages may provide all the information necessary. If you want more information on how good or how bad a part is, for example, to assess capability, use gages with numeric readouts.