Measurements of Length

Linear measurements take place in one dimension and are absolute. Measurements are based on units of length. These lengths are pre-established and are constant.

In America, lengths for measurement are established by the United States system. These originated from English units which were taken from the Roman and Anglo-Saxon era. From the British system of measurement came the imperial system. From that, the American system has grown. The US National Institute of Technology prefers to use the International System of Unit with a variety of combinations according to career field and area of study. Although the metric system was formally entered into American law in the Metric Conversion Act of 1975, the US public has not resonated with its units of measurement and the system has not yet been selected official.

Units of Length

A unit of length defines and expresses a dimension of distance or constant magnitude. The most commonly used units of length are expressed here.

0.001 in. / one-thousandth of an inch

0.01in.  /one-hundredth of an inch

0.1in   /one-tenth of an inch

1/64 in.  /one sixty-fourth of an inch

1/32 in  /one thirty-second of an inch

1/16 in.  /one sixteenth of an inch

1/8 in.  /one eighth of an inch

¼ in.  /one fourth of an inch

½ in  /one half of an inch

12 inches = 1 foot

3 feet = 1 yard

5280 feet = 1 statute mile

6080 feet = 1 nautical mile

1 millimeter = 0.039 in.

10 mm = 1 centimeter(cm) = 0.394 in.

10 cm = 1 decimeter (dm) – 3.937 in.

10 dm = 1 meter (m) = 100 cm = 39.37 in. = 3.28 ft.

1000m = 1 kilometer (km) = 3280.8 ft.

2.54cm = 1 in.

Micron = one-thousandth of a millimeter (mm).

Measuring Devices

Modern man has devised and created several tools for linear measurements, length, or range. A partial list of these are listed here.

Caliper, architect’s scale, engineer’s scale, feeler gauge, gauge blocks, Gunter’s chain, measuring rod, meter stick, micrometer, opisometer, pacing, ruler, stadiometer, surveyor’s wheel, tape measure, thread pitch gauge, yard stick, ranging, electronic distance meter, ultrasonic ranging module, radar distance, laser range finder, GPS, hypsometer, interferometer, macrometer, odometer, rangefinder, tachymeter, taximeter, tellurometer, travelling microscope, altimeter.