In this chapter, we examine various means available to measure certain physical quantities. In Chapter 6, we have reviewed various transducer mechanisms underlying the measurement system function, such as changes in resistance. (Many physical quantities cause resistive changes, such as temperature, strain (caused by force or pressure), light intensity, humidity, etc.) Our purpose in this chapter is to examine the most commonly employed sensor types used to measure a given quantity, such as temperature. The quantities which we shall consider here are-acceleration, velocity and position (angular and rectilinear), temperature, pressure, force, torque, gyroscopic measurement of angular velocity and position, the GPS system, and an introduction to spectrophotometry.