Units of Measure
Length and Distance

What instrument measures length or distance?

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Wiki User
May 15, 2017 6:41PM

It depends on the meaning of length. Typically it means a unit of distance but it can also be applied to the passage of time, such as the duration of a piece of music. Thus a time-piece, such as a stopwatch, would be the instrument of choice when measuring a length of time.

For units of distance, there are a huge number of instruments available:

  • Calipers and micrometers
  • Rulers and meter or yard sticks or line gauges
  • tape measures,
  • surveyor's wheels,
  • micrometers,
  • rangefinders
  • laser rules.
  • Walking wheels
  • RADAR
  • SONAR
  • LIDAR

Which instrument you use largely depends on how accurate the result needs to be (the tolerance), combined with the size of the object or the distance being measured. Generally, the greater the distance, the greater the tolerance.

Measuring tapes are more flexible than straightedge rulers and can accurately measure much greater distances, typically up to 10m. Today, they are made from cloth or fiberglass (such as a tailor's measure) or from a stiff, curved metallic ribbon that can retract into a coil (such as a carpenter's or constructor's measure). Surveyor's tapes are often made from durable plastic or fiberglass and allow more accurate measuring over much greater distances, usually up to 100m or more.

Micrometers are used when measuring the size of distant objects. Modern micrometers are often GPS-based systems used to perform geodetic measurements.

Micrometers and calipers are generally used in engineering applications where straightedge rulers would be impractical, such as when measuring the diameter of a column or when measuring the gauge of a threaded bolt.

Laser rulers are a new type of measuring device, designed to specifically measure the distance to an object, where a laser beam can be reflected back to the device. Handheld devices are generally low-power devices so their accuracy is limited to within 100m or so, but more powerful lasers can measure greater distances, including the distance to the moon (where reflectors were specifically placed during the moon landings in the late 60's and early 70's).

In microscopes, there is commonly a glass slide marked with an engraving that goes down to a few microns (micrometer scale). The glass slide with the engraved lines is known as a graticule or reticule).

To measure distance traveled, a pedometer is carried by walkers to measure distance walked. An Odometer is fitted to vehicles, including bicycles, to measure distances traveled (miles or kilometers).

You may use a ruler.

Examples of common instruments used for measuring length are the ruler, (for measuring milimeters, centimeters, inches, and 1 foot), the yardstick, (which is 3 feet long, [36 inches], and measures milimeters, centimeters, inches, and about 1 meter, {3.28084 feet}). There are also tape measurers that can measure all of the previously listed measurements and vary on the longest length they can measure. Units of length are based on feet or meters. Tools for measuring length range from simple rulers to lasers. A ruler
I would say a ruler or a tape measure.

Top Answer
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Wiki User
May 10, 2013 4:51PM

A ruler, a tape measure, a measuring wheel or a laser range finder.