calibration

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.

Veritasium visits NIST to explain Standard Reference Materials, the carefully characterized items such as peanut butter used to calibrate instruments and keep measurements consistent. It covers why they exist and why they are expensive.

Raw 1991 home footage of a working Etak Navigator, the 1985 in-car navigation system that predated consumer GPS. It shows the system's cassette-based map display and explains its augmented dead reckoning using wheel sensors.