en عمومى General كاربردي Applicable Atomic magnetometers have found widespread applications in precise measurement of the Earth’s magnetic field due to their high sensitivity. In these measurements, various methods have been utilized to compensate the Earth’s magnetic field in an unshielded environment. In this paper, we have proposed a method based on finding the minimum resonance frequency (corresponding to minimum magnetic field) by producing the opposite magnetic field through three pairs of Helmholtz coils. The exact value of the Earth’s magnetic field vector is obtained as 35.132 μT with an accuracy of 2 nT by using this method. Atomic magnetometers, Earth magnetic field, Helmholtz coils, Zeeman Effect. 25 30 http://ijop.ir/browse.php?a_code=A-10-451-2&slc_lang=en&sid=1 Amin Zamani a_zamani@sbu.ac.ir 10031947532846003111 10031947532846003111 No Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran Maliheh Ranjbaran m_ranjbaran@sbu.ac.ir 10031947532846003112 10031947532846003112 No Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran Mohammad Mehdi Tehranchi teranchi@sbu.ac.ir 10031947532846003113 10031947532846003113 Yes Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran, Physics Department, Shahid Beheshti University, Tehran, Iran Seyed Mohammad Hossein Khalkhali m_khallkhali@khu.ac.ir 10031947532846003114 10031947532846003114 No Physics Department, Kharazmi University, Tehran, Iran Seyedeh Mehri Hamidi m_hamidi@sbu.ac.ir 10031947532846003115 10031947532846003115 No Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran