Bambang Widiyatmoko

Prototype fiber Bragg Grattings (FBG) sensor based on intensity modulation of the laser diode low frequency vibrations measurement

In general, Fiber Bragg Grating (FBG) sensor works based on observation of spectral response characteristic to detect the desired parameter. In this research, we studied intensity response characteristic of FBG to detect the dynamic strain. Experiment result show that the reflected intensity had linier relationships with dynamic strain. Based on these characteristics, we developed the FBG sensor to detect low frequency vibration. This sensor is designed by attaching the FBG on the bronze cantilever with dimensions of 85×3×0.5 mm. Measurement results showed that the sensor was able to detect vibrations in the frequency range of 7-10 Hz at temperature range of 25-45 ˚C. The measured frequency range is still within the frequency range of digging activity, therefore this vibration sensor can be applied for oil pipelines vandalisation detection system.

Analysis of fiber Brag grating responsivity in the cantilever system using ANOVA

Information about the weight is one of the most important parameters to be known. In this research Fiber Bragg Grating (FBG) application has been tested to measure the amount of weight. Weight measurement is done by integrating FBG at a mechanical scale using the cantilever principle. The load makes the cantilever stretch so that the distance between grating of FBG change. The test is done by providing load on each area of platform scales with the size of 3x3 matrix. The distance change of grating correlates with the change of Bragg Wavelength. FBG interrogator was used to measure this Bragg Wavelength changes related with the weight of the applied load. There were 9 (nine) areas which the weight was measured. Further the data measurement is analyzed using ANOVA to evaluate the data relation of each area. The data analyzed gave three groups of 9 (nine) areas that have relation among groups. The Group I (A row) and Group II (B row) did not have similar data in each area, but The Group III (C row) had a sim...

Optical response characteristics of strained uniform fiber Bragg grating using laser diode

The working principle of the FBG strain sensor using laser diode (λ = 1551.9 – 1553 nm) as a light source is reported. Experimental results show that by straining the bare uniform FBG (λB = 1552 nm) for every 0.01 mm in room temperature, the transmitted and refelcted power were varied according to the state of FBG strains.

Preliminary design of land displacement-optical fiber sensor and analysis of observation during laboratory and field test

An optical fiber optic sensor for detecting land displacement is discussed in this paper. The sensor system consists of a laser at wavelength 1.3 um, optical fiber coupler, optical fiber as sensor and light transmitting media, PIN photodiodedetector system, data logger and personal computer. Sensor was made from a curved optical fiber with diameter 35 mm, which will be changed into a heart-shape fiber if it is pulled. The heart-shape fiber sensor is the modification of the earlier displacement fiber sensor model which was in an ellipse form. Light to and from the optical fiber sensor was transmitted into a length of a multi core, single mode optical fiber cable. The scheme of the optical displacement sensor system has been described here. Characterization in the laboratory has been done by applying a series of pulling mechanism, on the heart-shape fiber sensor; which represents the land displacement process. Characterization in the field was carried out by mounting the sensor system on a scaled-down model of a land slope and artificially reproducing the landslide process using a steady-flow of artificial rainfall as the trigger. The voltage sensor output was recorded during the artificial landslide process. The displacement occurence can be indicated from the declining of the sensor signal received by the detector while the reference signal is steady. Characterization in the laboratory resulted in the performance of the optical fiber land displacement, namely, sensitivity 0.027(mV/mV)/mm, resolution 0.37 mm and measurement range 30 mm; compared with earlier optical fiber sensor performance with similar sensitivity and resolution which works only in 8 mm displacement range. Based on the experiment of landslides simulation in the field, we can define a critical condition in the real situation before landslides occurence to take any measures to prevent more casualties and losses.

Design of instrumentation for flatness measurement of railroads

Transportation safety issues are very important; one of which is related to a mode of land-based transport in particular a railroad train. This research thus develops and designs a flatness measurement system consisting of multiple sensors to determine whether railroads are flat. The method used in this study is to deploy sensors for measuring flatness on railway carriages from one railway station to another. The measurements provide field data about translational and rotational shifts of position and angle in particular locations. The magnitudes of the shifts are obtained from the Inertial Measurement Unit (IMU) integrated sensor that contains Accelerometer Sensor, Compass Magnetometer, Gyroscope, Air Pressure Sensor and GPS. LabVIEW 2013 is here used in cooperation with GUI systems equipped with a data logger for automatic data saving.