Abstract: Distance is a physical quantity that used in many applications. In the field of sensor, distance is a main physical quantity that can be used for many measurements. In this paper, we will show the use of flat coil element for measuring of very small distance (proximity). Based on this ability, we develop sensors for measuring mechanical quantities such as pressure, vibration and moment of force. As a proximity sensor, the flat coil element is used to measure the position of an object (seismic mass) as a function of time. Its working principle is based on position change of a seismic mass that put in front of a flat coil element. The flat coil is a part of a LC oscillator; therefore the change of seismic mass position will change its resonance frequency. Based on the developed flat coil element, we have successfully developed air pressure sensor. The working area of the developed pressure sensor can be set by adjusting the membrane thickness. The flat coil element has also been developed for vibration sensor. Vibration like earthquake is a phenomenon of physics. The characteristics of these vibrations can be used as an early warning system so as to reduce the loss or damage caused by earthquakes. For this purpose the sensor should measure vibration in low frequency area. The developed vibration sensor can be used to measure the vibration until 0.2 Hz. Finally, we have succeeded in developing the flat coil element for moment of force sensor. The developed sensor showed good reproducibility and good reliability with relative error under 3%. Sensor models based on mathematical approach of each sensor have also been developed.

Brief Biography of the Speaker:
Mitra Djamal received B.Sc. degree in physics from Institut Teknologi Bandung in 1984 and the Dr.-Ing. degree in electrical and electronic engineering, especially in the field of sensors, in Universitaet der Bundeswehr Muenchen, Germany in 1992. He joined the Faculty of Mathematics and Natural Sciences, ITB, since 1986. In 2001 he became Associate Professor and became full Professor since 2009. His research interest is about sensors and instrumentation. Currently he is reviewer of some international journals, patent holder of some sensors, member of IEEE, chairman of Indonesian Sensor and Actuator System Society (ISASS) and vice chairman of Indonesian Physical Society (HFI). He is also author of more than 125 papers published in international journals and conference proceedings, and invited book chapters.