Basic types of measuring instruments.
Physics, like other science, starts with observation in the world around us or from laboratory experiments, Often involving measurements. Every measurement has its own unit. In the physical sciences measurement is a physical quantity, a quantity that can be measured. Some examples of physical quantities are mass, volume, length and time. A physical quantity is expressed as the product of numerical value and physical unit. Before a physical quantity can be measured a standard or unit must be chosen and defined. In the S.I system (Systeme Internationale d’Unites) there are seven basic units and from these the units of all other quantities, called derived units, can be obtained by multiplying or dividing the basic units. The system is convenient one because all the derived units are connected with as few basic units possible. There are many measuring instruments used in the present world. Few examples are shown in the picture above. These various instruments measure the basic quantities, Length, Mass, Time, Electric Current, temperature, Luminous intensity. Without the instruments we cannot measure them. Can we see the time, just by looking at the surroundings and sun? No, We need particular instrument (Clock). Likewise, a measuring instrument is instrument that shows the extent or amount or quantity or degree of something (Base Quantity). Measuring Tools were among the earliest tools invented by man. Primitive societies needed rudimentary measurement tools for many tasks: constructing dwellings of an appropriate size and shape, fashioning clothing, or bartering food or raw materials. Application of Measuring Instruments in day to day Life.
Measurements are so often taken for granted we sometimes do not appreciate the grand importance...