"Magnetoresistors can replace induction sensors in applications like nondestructive testing and metal detection, where high spatial resolution or low frequency response is required. Using an AC excitation field the magnetic response of eddy currents is detected. Although giant magnetoresistive (GMR) sensors have higher measuring range and sensitivity compared to anisotropic magnetoresistors (AMR), they show also higher hysteresis and noise especially at low frequencies. Therefore AMR sensors are chosen to be evaluated in low noise measurements with combined processing of DC and AC excitation field with respect to the arrangement of processing electronics. Circuit with a commercial AMR sensor HMC1001 and AD8429 preamplifier has the noise of 125 pT/rtHz at 1 Hz using the flipping technique. Without the flipping, the noise combined with the 1/f noise of the amplifier results in 246 pT/rtHz at 1 Hz." . . "Jano\u0161ek, Michal" . . "P(GD102/09/H082), S" . "Vyhn\u00E1nek, Jan" . . . . "[9066CF958EE8]" . "3"^^ . "Ripka, Pavel" . . . "Low Frequency Noise of Anisotropic Magnetoresistors in AC-excited Magnetometers"@en . "147492" . "Low Frequency Noise of Anisotropic Magnetoresistors in AC-excited Magnetometers"@en . . . . . . "RIV/68407700:21230/12:00194968!RIV13-MSM-21230___" . "Low Frequency Noise of Anisotropic Magnetoresistors in AC-excited Magnetometers" . . . "Magnetoresistors; magnetometers"@en . "21230" . "3"^^ . "Magnetoresistors can replace induction sensors in applications like nondestructive testing and metal detection, where high spatial resolution or low frequency response is required. Using an AC excitation field the magnetic response of eddy currents is detected. Although giant magnetoresistive (GMR) sensors have higher measuring range and sensitivity compared to anisotropic magnetoresistors (AMR), they show also higher hysteresis and noise especially at low frequencies. Therefore AMR sensors are chosen to be evaluated in low noise measurements with combined processing of DC and AC excitation field with respect to the arrangement of processing electronics. Circuit with a commercial AMR sensor HMC1001 and AD8429 preamplifier has the noise of 125 pT/rtHz at 1 Hz using the flipping technique. Without the flipping, the noise combined with the 1/f noise of the amplifier results in 246 pT/rtHz at 1 Hz."@en . . . "Low Frequency Noise of Anisotropic Magnetoresistors in AC-excited Magnetometers" . . "RIV/68407700:21230/12:00194968" . .