Experimental research of proton magnetometer

Proton magnetometer is a static magnetic measuring instrument of high sensitivity based on Larmor precession effect and is widely used in the survey of geological environment, underground buried objects and geomagnetic anomaly detection, etc. In this paper, a new method of magnetic measurement based on the system of DSP+CPLD is composed. The tests were conducted to verify the sensitivity of this instrument under ideal and actual conditions. Two types of function signal generators, the GFG-8255A and EE1420DDS, which can supply signal with high signal to noise ratio (SNR) and accurate phase, are used to simulate the local magnetic frequency. Both of them produce the signals that imitate the frequency of the local magnetic field. The precision of 0.0037nT and 0.0054nT with different function signal generators under the ideal condition were achieved. The precision of 0.1nT in an actual environment was obtained. The experimental results indicate that the sensitivity of this instrument approached the level of commercial instrument.