Checking and calibrating measuring instruments and test equipment can be done with a gauge block.
A gauge block is made of steel, carbide or ceramic.
They can be used as secondary standards for direct measurement.
Each gauge block embody a certain length with a high accuracy.
If needed several blocks can be combined in order to create any dimension that need to be measured.
Gauge Blocks are available in various forms like parallel, angular, spherical or cylindrical.