Knowledge about any thing is complete only when it can be expressed in numbers and something is known about it. Thus for every kind of quantity measured,there must be a unit to measure it and express it in numbers of that unit. The unit has to be followed by all and hence there must a universal standard. Most important parameter in Metrology is the length which can be measured in several forms and in several ways.A measurement plays a vital role in every field of investigation and present days Scientific and Technological progress has resulted from progress in the field of measurements.