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

IMPLEMENTASI EKTENSOMETER UNTUK MONITORING PERGESERAN PERMUKAAN TANAH DI SEKITAR JALUR KERETA API PADA LOKASI KM 107 PURWAKARTA

ABSTRACTThe number of railways users are increasing annually. Thus, stakeholder need to improve the transport safety and security system, especially for the anticipation system towards natural disaster. One of common disaster occurred on the railway track is landslide. Many factors are causing landslide, they are unstable soil, rainfall and high level water in the soil. Some of landslide incidents on railway track were caused the train to derail and it became a threat toward the railways user. For this, there is a need of landslide early warning system by implementing ground movement monitoring system on the track which considered landslide-prone. Ekstensometer is one of the tools that can be used to detect soil movement in a region. In this research, ekstensometer was developed using a rotary encoder as its main component. The result of the study showed that infiltration of rainwater into the soil may cause the soil layer easily to slope and unstable. Shifting ground in the location of measurement occured for between 3,5 mm and 10 mm on heavy rainfall. The research and observation conducted at the railroad track for Cikampek - Padalarang in Km 107+335, Purwakarta region, West Java. The results of the research are expected to be significant information as the basis data in order to prevent any landslide on the railroad infrastructure.ABSTRAKPengguna moda transportasi kereta api tercatat meningkat dari tahun ke tahun. Pihak stakeholder perlu meningkatkan sistem keselamatan dan keamanan transportasi, terutama sistem antisipasi terhadap kejadian bencana alam. Salah satu bencana yang cukup sering terjadi pada jalur kereta api adalah tanah longsor. Banyak faktor yang dapat menyebabkan terjadinya tanah longsor, antara lain struktur lapisan tanah yang labil, curah hujan, dan tingginya kadar air di dalam tanah. Beberapa kejadian tanah longsor pada jalur kereta api dapat menyebabkan anjlok dan menjadi suatu ancaman terhadap keamanan dan keselamatan perjalanan kereta api. Oleh karena itu, perlu dilakukan antisipasi terhadap kejadian tanah longsor secara dini, yaitu dengan menerapkan sistem monitoring pergerakan tanah pada jalur yang dianggap rawan longsor. Ekstensometer adalah salah satu piranti yang dapat digunakan untuk mendeteksi pergeseran permukaan tanah pada suatu wilayah. Pada penelitian ini ekstensometer dikembangkan dengan menggunakan rotary encoder sebagai komponen utamanya. Hasil pengamatan menunjukkan bahwa infiltrasi air hujan kedalam tanah menyebabkan lapisan tanah cenderung mudah bergerak dan labil. Pergeseran permukaan tanah di lokasi pengukuran mencapai 3,5 mm dan 10 mm pada saat terjadi curah hujan tinggi. Penelitian dan pengamatan dilakukan di sekitar rel kereta api jalur Cikampek - Padalarang km 107+335, Kabupaten Purwakarta - Jawa Barat. Hasil penelitian ini diharapkan dapat menjadi informasi penting untuk melakukan langkah-langkah penanganan dan pencegahan tanah longsor pada prasarana rel kereta api

Karakterisasi Rugi Lengkungan Serat Optik Dengan Optical TIME Domain Reflectometer Untuk Penggunaannya Sebagai Sensor Pergeseran Tanah

Pada makalah ini diuraikan karakterisasi rugi lengkungan serat optik ragam tunggal yang akan digunakan sebagai sensor pergeseran tanah dengan menggunakan Optical Time Domain Reflectometer (OTDR). Karakterisasi dilakukan untuk dua jenis serat, yakni produk Fujikura yang biasa digunakan untuk sistem komunikasi dan produk Newport yang dirancang untuk sistem sensor. Masing-masing serat tersebut panjangnya lebih dari seratus meter untuk memungkinkan pengukuran dengan OTDR. Alasannya adalah agar daya optis yang terukur adalah dari cahaya yang merambat di dalam inti serat, tidak terpengaruh oleh cahaya yang merambat di selubung serat sebagaimana bisa terjadi bila serat optiknya pendek. Karakterisasi ini dilakukan untuk merancang konfigurasi (bentuk dan ukuran) sensor bila serat tersebut akan digunakan sebagai Fiber Extensometer untuk sensor pergeseran tanah. Hasil karakterisasi berupa grafik rugi lengkungan sebagai fungsi dari diameter lengkungan yang dialami serat. Terlihat hubungan eksponensial antara rugi dengan diameter lengkungan sebagaimana dinyatakan oleh persamaan teoritisnya. Hasil karakterisasi menunjukkan bahwa serat optik jenis “telecommunication grade” Fujikura dapat digunakan sebagai sensor pergeseran dengan diameter lengkungan antara 1.4 – 1.6 cm dengan sensitivitas (Perubahan rugi akibat Perubahan diameter lengkungan) sebesar 0.2 dB/mm nm, sedangkan serat optik jenis “sensor grade” Newport dapat digunakan sebagai sensor dengan diameter lengkungan antara 0.65 – 0.7 cm dengan sensitivitas 0.08 dB/mm, untuk cahaya dengan panjang-gelombang 1310.We describe in this paper the bending loss characterization of single mode optical fibers that will be used as land displacement sensor utilizing an Optical Time Domain Reflectometer (OTDR). Two types of optical fiber are characterized, namely a telecommunication grade fiber from Fujikura and a sensor grade fiber from Newport. The length of both fibers is more than a hundred meter in order OTDR measurement can be performed. The reason is to make certain that the measured optical power comes from light propagating inside the core of the fiber, not affected by that propagating along the cladding as usually happened in short fibers. The aim of this characterization is to obtain the sensor configuration (form and size) if the fiber will be used as Fiber Extensometer for land displacement sensor. The result of this characterization is curves of bending loss as a function of fiber bend diameter. It is shown that the curve is exponential as expressed by its theoretical expression. The results of our characterization are as follows: the Fujikura telecommunication grade fiber can be used as displacement sensor with bend radius between 1.4 – 1.6 cm and sensitivity (the change of bending loss caused by the change of bend diameter) of 0. 2 dB/mm, while the Newport sensor grade fiber can be used as sensor with bend radius between 0.65 – 0.7 cm with 0.08 dB/mm sensitivity, for light with a wavelength of 1310 nm

Pembuatan Dan Karakterisasi Sumber Dan Detektor Cahaya Untuk Ekstensometer Serat Optik

Pada makalah ini diuraikan pembuatan sumber cahaya menggunakan diode laser yang distabilkan menggunakan teknik APC (Automatic Power Control), dan detektor cahaya yang merupakan paduan suatu diodefoto PIN dan penguat operasional derau rendah jenis CA-251F4 untuk digunakan pada sistem ekstensometer serat optik. Syarat utama bagi ekstensometer serat optik yang berbasis Perubahan intensitas cahaya adalah tersedianya sumber cahaya dan detektor cahaya yang andal. Intensitas cahaya yang dipancarkan oleh sumber cahaya harus tetap nilainya (kalau pun berubah maka Perubahannya harus dalam batas toleransi penggunaan). Detektor yang digunakan harus peka terhadap Perubahan intensitas cahaya dan mempunyai taraf derau yang rendah. Adapun untuk karakterisasinya (pengamatan kestabilan intensitas cahaya sebagai fungsi waktu) digunakan Picoscope 3224 yang berfungsi sebagai data logger. Sumber dan detektor cahaya yang dibuat ini dapat digunakan pada sistem ekstensometer optis untuk mengukur pergeseran tanah dengan tingkat ketelitian 0.2 mm

RANCANGAN SENSOR PERGESERAN TANAH BERBASIS SERAT OPTIK UNTUK DETEKSI LONGSOR: STUDI AWAL (Measurement of Curvature Optical Fiber Loss As A Displacement Sensors In Landslide Detector)

The optical extensometer based optical fiber have been designed by Single Mode Optical Fiber with the basic component are light, optical fiber in circling condition and photodetector. Early experiment have been carried out loss optical fiber curvature of the correlation factor of a circle diameter of the displacement. Measurement results showed differences to laser intensity at the position of the optical fiber is straight and the position make to curve. Measurement made on the condition R1 = 18.7 mm as L1 = 0 mm until R2 = 15.6 mm as L2 = 9 mm. The working principles of equipment that is create when a laser through optical fiber missed in the curve and pull up to a certain frictions the loss geometry would be the bigger

Development of River Flow and Water Quality Using IOT-based Smart Buoys Environment Monitoring System

Efficient and accurate river water quality monitoring is needed to support laboratory testing based on on-site sampling. Therefore, we have developed a monitoring system for river flow and water quality using sensor-equipped buoys and the Internet of Things (IoT) concept. An ESP32 NodeMCU microcontroller integrated with WiFi and compatible with Arduino IDE is used in the system. The buoy is equipped with GPS to determine the position and flow speed and sensors to measure water quality parameters of pH and temperature. Data on position, flow velocity, and water quality parameters are transmitted over a WiFi network using the MQTT protocol. The data is recorded by the buoy and uploaded and displayed on the adafruit.io platform. Positioning was done by comparing the values displayed on the Neo-6M GPS with the Maps application on the smartphone. The results show that the GPS coordinate values are accurate. The water quality parameter values obtained have an error rate of 3.3% for the pH sensor and 1.02% for the temperature sensor. Thus, the system we have developed has the potential to be used as a substitute for field sampling-based river water quality monitoring systems

Performance evaluation and mathematical analysis of direct sequence and frequency hopping spread spectrum systems under wideband interference

This paper presents performance evaluation and comparison analysis of Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) systems. The evaluation and analysis are done based on the systems performance against wideband interferences. The interferences are signals with similar spectrum characteristic to the transmitted signals of DSSS and FHSS systems. Bit Error Ratio (BER) is used as evaluation parameter to assess the performance of both systems. Simulation and mathematical analysis are performed to test and verify the performance of both systems. Mathematical analysis also verifies that increasing Spreading Frequency on certain conditions will reduce the BER. This research also points out that FHSS system has a better performance compared to DSSS system indicated by smaller BER