Designing & Testing Laser Microvibration Sensor

Abstract

In the past two decades, the optical sensor has been developed from the experimental stage to the practical applications. For instance, distributed optical sensors have been installed in dams and bridges to monitor the performance of these facilities. It can be anticipate that optical sensors will become widespread applications in sensing technology. In this work a design of an optical microvibration sensor has been developed depending on a laser beam creation. This microvibration sensor consists of three main parts. The first part is the laser source (laser diode) which can be sense the vibration on the bodies by direct contact between the laser source and the vibrated body, or indirect contact which done by directing the beam of laser to the vibrated body, and receive the reflected part of the beam. The second part is an electronic circuit (receiver) which contents a photodetector that processes the photo signal to electric signal. The third part is the output signal device. The type of which can be varies as required according to nature of study. Speaker, graphometer and oscilloscope are suggested here. The results obtained in this work, conclude the developed microvibration sensor device can efficiently measure the microvibrations applying the direct contact and indirect contact between the sensor and the vibrated object. The VI strength of the measure signals depends on the physical contact between the laser and the object in sense by direct contact. This microvibration sensor can be used to curry the audio signals. And substitution the measuring device with the speakers makes the microvibration sensor ready to hear low noises (sounds).