There are many instruments used to measure length including rulers, tape measures, micrometers, gauges and vernier calipers. There are also instruments that make use of scientific principles to deduce length where it may not be directly measured. Measuring lengths accurately has been a driving force behind much of human civilization.
Measuring the length of waves of light, sound, X-rays and radio waves is accomplished by analyzing the composition of the waves using scientific techniques that can be incorporated into the design of instruments. Measuring distances in outer space requires instruments that make use of radar, parallax, cepheids, supernovae, red-shift and Hubble's Law. In 225 B.C., Eratosthenes was the first person to accurately measure the circumference of the Earth. He did this by comparing the lengths of shadows in two different cities on the summer solstice and applying geometric principles.Learn More
To measure the square footage of a room, use a measuring tape to determine both the width and the length of the room, and then multiply the length of the room by the width of the room. Materials needed include a tape measure.Full Answer >
The length of a leg can be measured using radiography or by using a tape measure to determine the length between two predetermined points while the person is standing. The measurement method is chosen depending on the degree of accuracy needed.Full Answer >
According to Dictionary.com, a thermometer is used to measure temperature. A thermometer is often a sealed glass tube containing a column of liquid mercury. The mercury expands, contracts, falls or rises in accordance with temperature changes.Full Answer >
A metric ruler is used to measure the length, height and width of an object or the distance between two points, objects or places. Depending on the length of the metric ruler, it can be divided into millimeters, centimeters, decimeters or meters.Full Answer >