micrometer caliper การใช้

• Micrometers are usually, but not always, in the form of calipers ( opposing ends joined by a frame ), which is why "'micrometer caliper "'is another common name.
• The first documented development of handheld micrometer-screw calipers was by Jean Laurent Palmer of Paris in 1848; the device is therefore often called " palmer " in French, and " tornillo de Palmer " ( " Palmer screw " ) in Spanish . ( Those languages also use the " micrometer " cognates : " microm鑤re, micr髆etro " . ) The micrometer caliper was introduced to the mass market in anglophone countries by Brown & Sharpe in 1867, allowing the penetration of the instrument's use into the average machine shop.