How Granite Surface Plates Are Calibrated and Reconditioned
oxtoolco · Demo · YouTube title: Surface Plate Calibration and Conditioning
Why it's here
Cited in threads on flatness and precision as a glimpse into a niche metrology profession.
What it covers
A look at how granite surface plates are inspected, calibrated and reconditioned using an autocollimator, a repeat meter and diamond-charged cast iron laps. Measurements are at the level of millionths of an inch.