Dynamic Characterization of Macrobending Loss Optical Fiber-Based Load Sensor

The weight of vehicles passing through the road greatly affects road damage, so it is necessary to have a non-stop weighing system or Weight in Motion (WIM). In this study, the dynamic characterization of the WIM sensor was carried out based on the principle of optical fiber macrobending. In this study, a single-mode step-index optical fiber was used as the sensor material and a laser diode with a power of 5 mW and a wavelength of 1,550 nm as a light source. Characterization was carried out by running over the sensor using a motor with three variations of speed, namely 10 km/hour, 15 km/hour, and 20 km/hour. Two different conditions were also carried out, namely, the sensor was directly crushed and the sensor was reinforced in the form of a half-cylinder wooden beam. The test was carried out with three different types of sensors. From the observations, data shows that the addition of a beam can increase the accuracy of the reading as seen from the smaller the difference in the output voltage reading for the same type of sensor and vehicle speed. Besides that, there is a strengthening of the sensor resistance up to 10 times which is known from the sensor output voltage where the voltage at the addition of the beam is 1/10 of the reading without the beam. This is due to an increase in the sensor area exposed to the load

Study of Microbending Loss Single Mode Optic Fiber in Sand Powder Against Pressure

Research has been carried out to further investigate specifically the effect of sand powder, both the size of the sand grains and the thickness of the sand powder on the photodetector output as an advanced study of the single-mode optical fiber microbending loss theory in sand grains to pressure. This was done to investigate the response of optical fibers due to microbending loss to the load and determine the size of the sand particles that are most effectively used as a compiler of load sensors. The principle works to test the response of load sensors based on single-mode fiber optic microbending loss in the form of photodetector output when given a large variety of pressure. The method used in this research is to observe the reduction in the intensity of the light transmitted through optical fibers in the form of a voltage drop that is read by MMD that is connected to the photodetector. The reduced light intensity shows that the load sensor experiences optical attenuation of the laser as a light source with a wavelength of 1550 nm and a power of 1.47 mW. Microbending loss is caused by mechanical pressure that can change the direction of optical signal transmission and the radius of the curve is equal to or less than the diameter of a bare optical fiber. Observations were made using 12 load sensors with variations in the size of the sand grains in each diameter of the hose. The results of this study obtained the size of the most effective grains of sand providing microscopic curvature in the optical fiber that is 0.05 mm in terms of the correlation between the response of sensors with various diameters to changes in pressure

Studi Tentang Pemanfaatan Pandu Gelombang Slab Berbasis Polymethyl Methacrylate (PMMA) Hasil Fabrikasi dengan Teknik Spin Coating sebagai Alat Ukur Massa

Pandu Gelombang Slab telah banyak digunakan untuk berbagai macam aplikasi. Salah satu aplikasi Pandu Gelombang Slab adalah sebagai Alat Ukur Massa. Penelitian ini memfokuskan pada studi tentang aplikasi Pandu Gelombang Slab sebagai Alat Ukur Massa dengan melakukan pembebanan terhadap pandu gelombang hasil fabrikasi dengan lapisan tipis berbahan Polymethyl Methacrylate (PMMA). Proses fabrikasi dilakukan dengan Teknik Spin Coating dengan kecepatan putar 1000 rpm hingga 2000 rpm selama 60 detik. Dari hasil fabrikasi kemudian dilakukan karakterisasi untuk mengetahui ketebalan lapisan tipis yang dibuat kemudian dilakukan pengamatan dengan melewatkan laser He-Ne pada lapisan tipis melalui fiber optik single mode. Dari karakterisasi diketahui bahwa hasil fabrikasi merupakan Pandu Gelombang Slab single mode dengan ketebalan lapisan tipis 12,2 µm. Pandu gelombang tersebut kemudian diberikan pembebanan hingga sebesar 13,5637 gr. Dari penelitian diketahui bahwa Pandu Gelombang dapat dimanfaatkan menjadi Alat Ukur Massa dengan rentang pengukuran antara 1,8559 gr sampai dengan 3,6733 gr. Makin besar massa beban yang diberikan maka posisi sinar yang terpandu semakin turun

Wire Extensometer Based on Optical Encoder for Translational Landslide Measurement

A landslide is a natural disaster mostly accompanied by heavy rains, earthquakes, or volcanic eruptions. Due to its significant incurred losses, several studies have been conducted to develop a landslide monitoring system. In this report, we built and implemented optical-based wire-extensometers to measure and monitor a translational landslide in a prone area. This extensometer was built of an optical rotary encoder (whose shaft bonded to a spiral spring and sling rope) interfaced to a low-cost microcontroller as a principal component and subsequently linked to a GSM-based wireless network. The working principle of the employed sensor described in this paperwork is to count optical pulse signal and convert it into a length unit. This sensor can provide much better signal stability and show high resolution for a wide-range measurement than voltage- or current-based sensors. The specification of the engaged optical encoder provides 2000 pulses per rotation, leading to a length resolution of 0.011 ± 0.0083 mm with a speed limit of about 36 mm/s. Furthermore, the wire extensometer was examined in a remote place near a double-track train road to assess its performance in an actual field. A solar cell system was applied as its main power supply. An example of transmitted data shows a land shift from 12 mm to 150 mm, which is mainly triggered by high rainwater infiltration. This result demonstrates that the developed extensometer is deserved to be promoted for landslide monitoring in the geological research-work area