A Simple Instrumentation System for Large Structure Vibration Monitoring

A conventional instrumentation systems in monitoring vibration of large-scale infrastructure building such as bridges, railway, and others structural building, generally has a complex design. Makes it simple would be very useful both in terms of low-cost and easy maintenance. To make system become simple, low cost, and easy in maintenance, this paper proposes a distributed network for implementation system. The system consists of field bus topology, using single-master multi-slave architecture. Master is a control unit, built based on a PC equipped with RS-485 interface. Slave is a sensing unit; each slave is built by integrating a 3-axis vibration sensor within a microcontroller based data acquisition system. Vibration sensor is designed using the main components of a MEMS accelerometer. The software is developed for two functions; a control system hardware and a data processing. To verify performance of the developed instrumentation system, several laboratory tests have been performed. The result shows that the system has good performance

Application of Single MEMS-accelerometer to Measure 3-axis Vibrations and 2-axis Tilt-Angle Simultaneously

This paper discusses a technique of developing an integrated sensor system, to measure the mechanical vibrations in 3-axis and the tilt-angle in 2-axis simultaneously, using only single MEMS-accelerometer. Type of MEMS-accelerometer that used in this experiment is MMA7361L, which is an analog-type acceleration sensor in the form of MEMS, with a maximum sensitivity of 800 mV/g. The MMA7361L has three outputs of voltage (Vx, Vy, Vz) in response to the acceleration value "g" of each working-axis corresponding vibrating (gx, gy, gz). By using certain techniques in the design of signal conditioning circuits, then the MMA7361L can be used to detect parameters of the vibration in 3-axis and the tilt-angle in 2-axis at the same time, simultaneously. To accommodate five output signal of the sensor system, used a data acquisition system that was built based on PIC16F876 microcontroller, which are already contained five internal ADC with 10 bits resolution. Thus, the resulting integrated sensor system becomes very simple, minimal components, and inexpensive. The experimental results show that the developed integrated sensor system has capability to measure the 3-axis vibrations and the 2-axis tilt-angle, with fairly good accuracy

Pengembangan sensor seismik berbasis MEMS accelerometer

Sensor seismik merupakan komponen utama dalam bidang seismologi. Salah satu sensor seismik yang sering digunakan geofon, namun geofon memiliki kekurangan dalam mendeteksi getaran frekuensi rendah di bawah 10Hz. Dengan adanya kekurangan tersebut menjadi salah satu peluang bagi sensor MEMS yang memiliki rentang frekuensi lebih lebar dibandingkan dengan geofon.Pada penelitian ini sensor MEMS terkonfigurasi dengan pengkondisi sinyal yang telah dilengkapi dengan rangkaian integrator. Fungsi dari rangkaian integrator ini untuk mengubah MEMS Percepatan menjadi MEMS Kecepatan. Sehingga MEMS mampu mendeteksi kecepatan gerakan tanah menyerupai geofon. Hasil respon sinyal MEMS menunjukkan bahwa MEMS Kecepatan mampu mendeteksi getaran frekuensi 0.01Hz hingga 100Hz. Berdasarkan hasil respon frekuensi menunjukkan bahwa MEMS mampu digunakan sebagai sensor seismik

Implementation of MEMS Accelerometer for Velocity-based Seismic Sensor

Micro Electro Mechanical System (MEMS) accelerometer is commonly used as acceleration-based vibration sensor. The MEMS accelerometer is small device, simple in the implementation design, and relatively inexpensive. But in some fields of application, due to low frequency operation and also small magnitude of the measured signal, for example in seismology, velocity-based vibration sensor is usually more desirable than acceleration-based sensor. In this research, a velocity-based vibration sensor has been developed using MEMS Accelerometer device e.g. MMA7361L. The acceleration-based vibration signal from the MMA7361L is converted into a velocity-based vibration signal by using an integrator circuit module. This module is assembled by using a band-pass filter and an integral-amplifier. The laboratory test shows that the developed sensor system could detect both low and high-frequency vibration signals in velocity-based with good result. The sensor system has a frequency range of 0.02Hz to 148Hz. It is wider frequency than the geophone (seismic sensor), thus the velocity-based MEMS sensor system has capability for geophone replacement

Pengembangan Array sensor Suhu dan Sistem Akusisi Data Berbasis Mikrokontroler untuk Pengukuran Suhu Bawah Permukaan

Dalam penelitian ini dikembangkan sebuah sistem akusisi data untuk survei panas bumi. Untuk menghasilkan sistem instrumentasi yang mampu mengukur dan memonitor distribusi suhu bawah permukaan diperlukan sistem akusisi data yang murah dan efesien. Sistem dibangun berbasis jaringan sistem terdistribusi dengan topologi field-bus, menggunakan arsitektur single-master multi-slave. Master merupakan unit pengendali, dibangun berbasiskan sebuah PC yang dilengkapi dengan antarmuka RS-485. Slave merupakan unit sensing, tiap-tiap unit slave dibangun dengan mengintegrasikan sistem array sensor LM35 dengan sistem akuisisi data berbasis mikrokontroler menggunakan AVR ATmega8. Pengolahan data dari hasil pengukuran suhu ini menggunakan satu set komputer dengan perangkat lunak microsoft excel 2010 untuk menghasilkan grafik pada titik pengukuran. Hasil implementasi dari monitoring suhu ini akan mengambarkan distribusi suhu bawah permukaan tanah.A data acquisition system for geothermal survey was developed in this research. Cheap and efficient data acquisition system was required to produce the instrumentation system which was capable to measure and monitor the distribution of subsurface temperature. The system consists of field-bus topology, using single-master multi-slave architecture. Master is a control unit built based on a PC equipped with RS-485 interface. Slave is a sensing unit; each slave is built by integrating array sensor LM35 within AVR ATmega8a microcontroller-based data acquisition system. Measurement techniques included sounding and mapping system by placing four slaves planted in the depth of 2.5 m. Processing of data obtained from temperature measurements was performed using Microsoft Excel 2010 to produce graphics at point of measurement. The results of temperature monitoring will described the distribution of subsurface temperature

Penanganan Sengketa Pemilu

Tulisan ini mengupas salah satu masalah dalam pemilihan umum yang semakin penting dibahas, yakni masalah penyelesaian sengketa atau perselisihan pemilu. Masalah ini perlu untuk dibahas karena beberapa alasan

Pengembangan Sistem Akuisisi Data Nirkabel Untuk Pengukuran Distribusi Suhu Bawah Permukaan

Subsurface temperature distribution measurement can be performed using non-contact methods such as remote sensing and other satellite imagery, and method of contact is by direct measurement at the observation area. In this research a contact method was used by injecting iron pipes equipped with sensor into the ground. The digital temperature sensor that can reduce noise, communication systems using wireless networks, and data processing system user interface were used. Result of measurement and processing of the data showed that the distribution of heat towards one of the slave due to the sunlight direct exposure was 31oC in areas without anomalie

Memaksimalkan Derajat Keterwakilan Partai Politik dan Meningkatkan Akuntabilitas Calon Terpilih

Sesuai dengan judul, dua pertanyaan menjadi fokus tulisan ini.Pertama, formula pemilihan atau metode pembagian kursi macam apakah yang lebih menjamin keterwakilan partai politik yang lebih adil di lembaga perwakilan rakyat? Kedua, desainsistem pemilihan umum macam apakah yang lebih menjamin akuntabilitas calon terpilih