Sistem pentanahan merupakan kunci penting untuk keselamatan manusia dan peralatan listrik dari lonjakan arus akibat hubungan pendek atau sambaran petir yang tidak dapat di prediksi kemunculannya. Sistem pentanahan yang baik mempunyai hambatan pentanahan yang kecil sehingga mampu menyalurkan arus berlebih langsung kedalam tanah. Hambatan tanah berasal dari hambatan jenis tanah, sedangkan faktor yang mempengaruhi hambatan jenis tanah adalah faktor suhu, kelembaban dan bahan kimiawi yang terkandung dalam tanah tersebut.Tesis ini menyampaikan seberapa besar pengaruh yang ditimbulkan pasir dan batu pada tahanan jenis tanah murni. Dengan melakukan pengujian hambatan di tanah campuran pasir dan batu pada kondisi kelembaban dan suhu yang dikondisikan serta penambahan garam kemudian dibandingkan dengan pengujian pada tanah murni. Dalam pengujian diperoleh tanah campuran pasir dan batu memiliki hambatan jenis yang lebih tinggi dari tanah murni, namun nilai hambatan jenis dapat berubah oleh kondisi kelembaban dan suhu tanah, serta penambahan garam.

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The earthing system was the important key for the safety of humankind and electricity equipment from the increasing current from short circuits or the stroke of lightning that could not be predicted of its emergence. The good earthing system had the earth resistance that was small so be able to distribute the excessive flow direct into the land. The earth resistance came from the earth resistivity, whereas the factor that affected the earth resistivity is the temperature factor, humidity and the chemical material that were contained in this soil.This thesis delivered how big is the influence that caused by sand and the stone in pure resistance of the soil. By testing the earth resistance in of mixed sand and rock land on condition for humidity and the temperature that were conditioned as well as the increase in salt afterwards compared with the testing to the pure soil. In the test was received the land and mix of stone and sand had the higher earth resistivity than the pure soil, but the value of the earth resistivity could be changed by the condition for humidity and the temperature of the soil, as well as the increase in salt.