Calibration can also include the condition of the tips (flat and parallel), ratchet, and linearity of the scale. ITTC – Recommended Procedures : Sample Work Instructions Calibration of Micrometers. Flatness and parallelism are typically measured with a gauge called an optical flat, a disc of glass or plastic ground with extreme accuracy to have flat, parallel faces, which allows light bands to be counted when the micrometer's anvil and spindle are against it, revealing their amount of geometric inaccuracy.
Calibration can also include the condition of the tips (flat and parallel), ratchet and linearity of the scale. ITTC – Recommended Procedures : Sample Work Instructions Calibration of Micrometers. Flatness and parallelism are typically measured with a gauge called an optical flat a disc of glass or plastic ground with extreme accuracy to have flat, parallel faces, which allows light bands to be counted when ,the micrometer's anvil and spindle are against it revealing their amount of geometric inaccuracy.