Mathematical modeling of geophone magnetic ring for sensitivity studies

Mawa Patrick Luka, Ser Lee Loh, Dennis Ling Chuan Ching

Abstract


Geophone (model SM-24) pertaining its performance to detect surface wave at Free Wave Generator is analyzed. Sensitivity studies have been conducted to model the physical disadvantage such as spring suspension and magnetic field in geophone. From mathematical model of the ring permanent magnet, applying “superposition” has suggested a solution: an external resistor across its output terminal to amplify the exhibited linear damping behavior. Geophone with 60%, and 75% damping ratio are designed and built and the results show that 75% damping provide highest sensitivity. Analytic expression of vertical component of magnetic field shows that the damping ratio can be increased physically by increasing the radius of the magnetic field, however, by modifying the SM-24 damping ratio, similar outcome can be obtained.


Keywords


Sensitivity; resistivity; magnetic field

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References


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DOI: https://doi.org/10.11113/mjfas.v13n4-1.896

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