ABSTRACT
Length and time are basic measurements. This chapter describes common methods for measuring displacement, velocity, acceleration, force, torque, and pressure. Motion involves displacement and time. The problem is to examine the medium or device by means of which the displacement information is transferred from a moving object to a stationary instrument, and to measure the time associated with the displacement. Optical methods are often used in instruments for motion studies. Holography is applied for studies in vibration. Uniaxial seismic instruments are generally used for acceleration measurements. A triaxial accelerometer simply consists of three uniaxial instruments, each of which is aligned in the x, y, or z direction. A transducer must interact with its environment in order to sense the measurand, or the desired input. At the same time, a transducer is susceptible to all the environmental effects, including the desired input and all the undesired inputs.
