PEMETAAN SUSEPTIBILITAS MAGNETIK ENDAPAN TANAH SUNGAI SAIL PEKANBARU

Mapping the value of the sedimentary magnetic susceptibility along the Sail Pekanbaru river using Surfer 11 Software has been carried out. The sample consisted of 70 location points consisting of 35 right bank edges and 35 left bank edges. The sampling method uses the grid method. The results of the magnetic level calculation show a range of values ​​from 0,03% to 0,19%.The results of magnetic degree value mapping indicate that the magnetic degree obtained is getting higher from upstream to downstream. The results showed that the suseptibility magnetic value of sediment in the Sail Pekanbaru river ranged from 0,82 × 10-8 m3 / kg to 3,44 × 10-8 m3 / kg, based on this value it can be estimated that the main magnetic particles of the sample are in the Sail Pekanbaru river is ilmenit. The results of mapping the magnetic susceptibility values ​​and mass susceptibility values ​​of the samples indicate that the magnetic susceptibility in the Sail Pekanbaru river from upstream to downstream is less.

PENDETEKSI LEVEL FLUIDA MENGGUNAKAN METODE FLOAT MAGNETIC LEVEL GAUGE BERBASIS HUMAN MACHINE INTERFACE (HMI)

ABSTRACTIn this present technology era, human needs of the intelligent equipment systems that automatically do all task itself, are increased. For designing that equipment, a component that can calculate, remember, and also make a decision is required. Computer has that ability, but only using computer for this purpose is not efficient. So we use the computer with a microcontroller.By using Float Magnetic Level gauge method in microcontroller, fluids level can be detector by a magnet system that can float as triggers of reed switch based on level change of fluids.The result is level in percent unit and it is displayed on interface that named Human Machine Interface in real time. Measurement on fluid level sensor is when the sensor floating in minimum level, it will give 4 mA value as the signal output. And then when the sensor floating in maximum level, it will give 20mA value as the signal output. That value is the standard value for sensor signal output in industry. After converting the value of signal ouput current to voltage value, it found out that the level sencor has 98% accurancy.Keyword: Measurement, Level, Fluids, Human Machine Interface, 4–20mAABSTRAKPada era teknologi saat ini, kebutuhan manusia terhadap sistem peralatan cerdas yang dapat melakukan pekerjaan sendiri secara otomatis semakin meningkat. Oleh karena itu untuk merancang sistem peralatan tesebut, dibutuhkan sebuah sistem yang dapat menghitung, mengingat, dan mengambil keputusan. Komputer memiliki kemampuan tersebut, namun masih kurang efisien jika hanya menggunakan computer untuk keperluan tersebut. Oleh karena itu computer dapat dikombinasikan dengan mikrokontroler.Menggunakan metode Float Magnetic Level Gauge pada mikrokontroler, ketinggian fluida dapat dideteksi dengan sistem magnet yang dapat mengapung sebagai pengaktif saklar reed switch berdasarkan perubahan level permukaan fluida.Hasil pengukuran berupa level dalam satuan persen ditampilkan dalam sebuah sistem interface dengan tampilan animasi yang disebut Human Machine Interface (HMI) secara realtime. Hasil pengukuran driver sensor level saat kondisi fluida pada kondisi minimum adalah 4 mA, dan pada kondisi fluida berada pada kondisi level maksimum adalah 20 mA. Nilai tersebut sesuai dengan standar sinyal output sensor yang digunakan pada sistem instrumentasi industri. Setelah melakukan konversi hasil pengukuran arus menjadi tegangan, diperoleh tingkat ketelitian sensor sebesar 98%.Kata kunci: Pengukuran, Level, Fluida, Human Machine Interface, 4–20mA

Telecoil-Mode Hearing Aid Compatibility Performance Requirements for Wireless and Cordless Handsets: Magnetic Signal Levels

Background: In the development of the requirements for telecoil-compatible magnetic signal sources for wireless and cordless telephones to be specified in the American National Standards Institute (ANSI) C63.19 and ANSI/Telecommunications Industry Association–1083 compatibility standards, it became evident that additional data concerning in-the-field telecoil use and subjective preferences were needed. Purpose: Primarily, the magnetic signal levels and, secondarily, the field orientations required for effective and comfortable telecoil use with wireless and cordless handsets needed further characterization. (A companion article addresses user signal-to-noise needs and preferences.) Research Design: Test subjects used their own hearing aids, which were addressed with both a controlled acoustic speech source and a controlled magnetic speech source. Each subject's hearing aid was first measured to find the telecoil's magnetic field orientation for maximum response, and an appropriate large magnetic head-worn coil was selected to apply the magnetic signal. Subjects could control the strength of the magnetic signal, first to match the loudness of a reference acoustic signal and then to find their Most Comfortable Level (MCL). The subjective judgments were compared against objective in-ear probe tube level measurements. Study Sample: The 57 test subjects covered an age range of 22 to 79 yr, with a self-reported hearing loss duration of 12 to 72 yr. All had telecoils that they used for at least some telecommunications needs. The self-reported degree of hearing loss ranged from moderate to profound. A total of 69 hearing aids were surveyed for their telecoil orientation. Data Collection and Analysis: A guided intake questionnaire yielded general background information for each subject. A custom-built test jig enabled hearing aid telecoil orientation within the aid to be determined. By comparing this observation with the in-use hearing aid position, the in-use orientation for each telecoil was determined. A custom-built test control box fed by prepared speech recordings from computer files enabled the tester to switch between acoustic and magnetic speech signals and to read and record the subject's selected magnetic level settings. Results: The overwhelming majority of behind-the-ear aids tested exhibited in-use telecoil orientations that were substantially vertical. An insufficient number of participants used in-the-ear aids to be able to draw general conclusions concerning the telecoil orientations of this style aid. The subjects showed a generally consistent preference for telecoil speech levels that subjectively matched the level that they heard from 65 dB SPL acoustic speech. The magnetic level needed to achieve their MCL, however, varied over a 30 dB range. Conclusions: Producing the necessary magnetic field strengths from a wireless or cordless telephone's handset in an in-use vertical orientation is vital for compatibility with the vast majority of behind-the-ear aids. Due to the very wide range of preferred magnetic signal levels shown, only indirect conclusions can be drawn concerning required signal levels. The strong preference for a 65 dB SPL equivalent level can be combined with established standards addressing hearing aid performance to derive reasonable source level requirements. Greater consistency between in-the-field hearing aid telecoil and microphone sensitivity adjustments could yield improved results for some users.