Micrometer calipers
Micrometer Calipers
Industry regularly makes measurements to a millionth (0.000001) part of an inch. A distance this small is called a MICROINCH. If the microinch were the thickness of a dime, and inch would be as high as four Empire State Buildings. In addition to the English measurement (inch, foot, etc.), industry, to a limited extent, also uses the metric system of measurement (meter). The United States has tentatively adopted the simplified and clarified metric system devised by the International Standards Organization (ISO). All of the states are in the process of converting to the metric system of the next several years.
Regardless of how fine industry can measure, the job at hand is to learn to read the rule to 1/64 in.; progress through 1/1000 (0.001) in. by micrometer and Vernier type measuring tools; and finally to 1/10000 (0.0001) in. by the Vernier scale on the hub of some micrometer calipers.
Metric based measuring tools will offer no problems. As a matter of fact, many think they are easier to learn to read than inch based measuring tools.
The Micrometer Caliper
A Frenchman, Jean Palmer, devised and patented a measuring tool that made use of a screw thread to make it possible to read measurements quickly and accurately without calculations. It incorporated a series of engraved lines on the hub and around the thimble. The device, called “Systeme Palmer,” is the basis for the
modern MICROMETER CALIPER. The modern micrometer caliper, known as a “mike,” is a precision measuring tool capable of measuring to 1/1000 (0.001) in. and when fitted with a Vernier scale to 1/10000 (0.0001) in. While manufactured in sizes up to 60 in., the movement of the spindle is limited to 1 in. Only the frame is enlarged.
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