Q. What do you mean by Sensors or Transducers?

In almost all engineering applications there arises a need tomeasure some physical quantities, such as positions, displacements, speeds, forces, torques, temperatures, pressures, or flows. Devices known as sensors or transducers convert a physical quantity to a more readily manipulated electrical quantity (such as voltage or current), such that changes in physical quantity usually produce proportional changes in electrical quantity. The direct output of the sensor may often need additional manipulation, known as signal conditioning, for the output to be in a useful form free from noise and intereference. The conditioned sensor signal may then be sampled and converted to digital form and stored in a computer for additional manipulation or display.