Meaning
Precise verification of coordinate measuring machines often employs length artifacts consisting of a series of precision blocks arranged in a line. A step gauge provides multiple calibrated distances along a single axis to verify the accuracy of a coordinate measuring machine or a height gauge. The device consists of a rigid carrier holding several high precision faces at known intervals that allow for the simultaneous check of multiple dimensions.
This arrangement saves time compared to using individual gauge blocks.
Calibration Accuracy
Traceability is maintained through a certificate that lists the exact distance from the first face to every subsequent step. Because the gauge is made from stable materials like steel or ceramic, it maintains its length over long periods. The faces are often lapped to a mirror finish to ensure a clear signal for contact probes.
Error Detection
Comparing the machine reading to the certified value of the step gauge identifies linear scale errors or pitch deviations. Since the gauge provides many data points, it can find non linearities that a single distance check might miss. This mapping is essential for creating error compensation tables in the machine software.
Proper Setup
Technicians often place the gauge at different angles across the machine volume to check for geometric squareness alongside linear precision. Proper setup must account for the weight of the artifact to prevent the machine table from sagging. The artifact is a fundamental part of the annual certification for metrology equipment.
