Inductive magnetic sensor（IMS） is one of the most widely utilized magnetic sensors in frequency domain electromagnetic method（FEM）

which consists of inductive coil and preamplifier.In order to enhance capability of IMS to detect weak magnetic signals and depth

a flat sensitivity curve at low frequency band is achieved and observation band is broaden

which is based on flux negative feedback technology.Utilize chopper pre-amplifier technology to decrease effect of 1/f noise on IMS

and to suppress output noise of IMS.The performance of IMS is tested in shielded room

band range is of 0.001 Hz

10 kHz

and input noise is 3nV/Hz

1/2

compared with magnetic sensor 3D-3

equivalent input noise is increased by 10.04 dB

whic

h guarantees performance for IMS in real project application.