1) Magnetic scales are increasingly being used in digital readouts and height masters instead of glass or metal scales due to advantages like higher accuracy even in dirty environments. 2) Magnetic scales work by magnetizing a plastic-coated steel strip with alternating magnetic poles that are detected by a reader head for displacement measurements. 3) The reader head houses electronic sensors and circuitry to convert the changing magnetic field into output signals for determining distance, and it is designed to operate reliably even in conditions with vibrations, dirt or coolant present.