Sciences are built upon measurements. Measurements are expressed with numbers. This allows the logic, precision and power of mathematics to be brought to bear on our study of nature. Units of measurement are names which characterize the kind of measurement and the standard of comparison to which each is related. So, when we see a measurement expressed as “7. 5 feet” we immediately recognize it as a measurement of length, expressed in the unit “foot” (rather than other possible length units such as yard, mile, meter, etc. ) Since many possible units are available for any measurement it is essential that every measurement include the unit name.

A statement such as “the length is 7. 5” is ambiguous, and therefore meaningless. Units of measurement are vital parts of any physical quantity. Just as the person is known by his or her name, the physical quantities are known by the units of measurement. Let us suppose that the length of the iron rod is 5 meters. This means that 1 meter is the standard used for the measurement of the length and that measured length is 5 times greater than the length of 1 meter. The unit of measurement is defined as the standard used for the measurement of the physical quantity. A Measuring instrument is a device for measuring a physical quantity.

In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Established standard objects and events are used as units, and the process of measurement gives a number relating the item under study and the referenced unit of measurement. Measuring instruments, and formal test methods which define the instrument’s use, are the means by which these relations of numbers are obtained. All measuring instruments are subject to varying degrees of instrument error and measurement uncertainty.

There are a lot of instruments to measure physical quantities that we use in our life. At school, office, home, field, and many more. We use rulers to measure the length, thermometer to measure the temperature, chronometer or time watch to measure the time, waterier to measure the electrical power etc. They truly measure the physical quantities when we need the answer for the measurement of that physical quantity. These instruments help us in various ways. Building a house or skyscrapers may be build with the help of hypotheses by measuring the height of the building.

Amount of milk to be filled in nee box in the factory with the help of electorate, and a lot more. They help us in our normal lives. Calculator may also help us to calculate all the sums and products. They would be what we must need for our physical quantity to be measured in our life time. Bibliography:- http://en. Wisped. Org/wick/Measuring_instrument http://en. Wisped. Org/wick/units_of_measurement http://www. Lip. Due/-?disdained/scenario/romance/units. HTML http://www. Parthenogenesis’s. Com/manufacturing-technology/64701-units-of- measurement- fundamental-and-derived-units-systems-of-measurement/ http://