Engineering structures undergo deformation due to various kinds of static and dynamic loads. Thus, monitoring of structure, specifically large structures such as high-rise building, bridges, dams etc., is essential to ensure its safe deformation behavior. With multifold rise of traffic, to provide safety and to prevent disaster, it has become necessary to detect uncharacteristic deflections and vibrations of bridges. The instruments which are often used for measurement of defl ection such as
strain gauge, accelerometer, tiltmeter, vision system, optometer, laser gauge meter etc are often cumbersome as well as costly in implementation. Moreover, they suffer from one defi ciency or the other. Hence, there is a need for a method which is simple, economic yet provides accurate and reliable measurement.