Browsing by Author "Umar, L."

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    ANALISA SIFAT FISIS SENSOR KOIL DATAR DENGAN VARIASI GEOMETRI
    (2014-03-26) Roberto, R.; Umar, L.; Setiadi, R. N.
    Flat coil inductive sensors based on Eddy currents principal could work without direct mechanical contact on the object, it could work continuously and reactively to the conductive material. This system is easily influenced by external disturbances. Based on inductance value due to changes in magnetic force lines that occurs between the sensor and conductor material (disturbances material). The system could be used as a detection of distance translation. The used sensors in this study was a flat coil made of Printed Circuit Board (PCB) technology with various geometric shapes, such as circle, square, rectangle and octagonal. Distance detection analysis were evaluated using a LC oscillator which was directly connected to a computer that able to transform a massive range measurement into frequencies. Characteristics of distance detection was influenced by geometry of the flat coil sensors with its highest value of frequency of 1.68 MHz for a circular shape, 1.66 MHz for an octagonal shape, 1.52 MHz for an square shape, 1.42 MHz for an rectangular shape, respectively with the minimum distances as far as 5 mm for each shape. The temperature tested as external disturbances caused change in characteristics of the transfer curve based on drift frequency for distance detection analysis based on a mathematical formula
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    PERANCANGAN SISTEM MONITORING MULTI SENSOR UNTUK EKOSISTEM ZONATERISOLIR BERBASIS MODUL GSM/GPRS+GPS SIM508
    (2014-03-26) Prayitno, Y.; Umar, L.; Setiadi, R. N.
    A monitoring design for isolated zone ecosystem based on GSM GPRS + GPS SIM508 has been successfully carried out. The monitoring system consists of several subsystems. They are multi sensor system, microcontroller, data transmission, and autonomous energy system which are integrated each other, and be able to provide information in the form of physical quantities. This system was designed to work automatically using an ATmega8535 microcontroller in order to control the whole system. In order to detect physical quantities i.e temperature and humidity, a series of multi sensors used a SHT75 sensor and a LM35DZ sensor that had been calibrated and characterized. Results of the sensor system readings were converted by a microcontroller of ATmega8535 before it was sent to the SIM508 module. SIM508 module was used as data transmitter. Testing of the monitoring system was done using a Hyperterminal. Results provided the information of temperature, humidity, time and location. There information were sent by the monitoring system via short message service (SMS) to Mobile Phone. The monitoring system works well and has a high degree of accuracy