Design Of Microtremor Monitoring Tools Using Accelerometer Sensor On Android Mobile To Determine The Natural Building Frequency In UNS Library

Design of Microtremor monitoring tools using accelerometer sensor on android phone to determine the natural frequency of buildings in UNS Library has done. This study aims to determine the ratio of resonance between the soil and building of UNS Library. The main sensor for recording microtremor activity is Accelerometer sensor on android phone. Microtremor activity recording is done on every building's floor of UNS Library and the surface of land outside the building.The recorded data has been sent to the server by telemetry methode. The data stored on the server then displayed in the graph on the microtremor web monitoring. Microtremor data is processed with the FFT to determine the dominant frequency. From the dominant frequency, ratio of resonance of soil and building of UNS Library could be found. The value of resonance ratio is 69.35 - 94.48% in the NS component and 70.42 - 98.61% in the EW component with low resonance status on each floor of the building.