An improved proton magnetometer for Earth's magnetic field observation
As a precision instrument to measure the earth magnetic field, proton magnetometer is widely used in different fields such as geological survey, buried objects detection and earth field variations. Due to poor signal to noise ratio (SNR) of the system, proton magnetometer suffers from low sensitivity which directly affects the performance. In order to increase the sensitivity, we present an improved proton magnetometer. First, the effect of matching resistance on Q value is discussed to enhance SNR, and high matching resistance has been chosen to improve the Q value of the resonant circuit. Second, noise induced by pre-amplifier is investigated in order to obtain low noise signal, and we adopt the JFET with noise figure less than 0.5dB as the pre-amplifier. Third, by using band-pass filter, low-noise output signal is obtained. Fourth, the method of period measurement based on CPLD is employed to measure frequency of the square wave shaped from the output sinusoidal signal. High precision temperature compensate crystal oscillator (TCXO) has been used to improve the frequency measurement accuracy. Last, experimental data is obtained through field measurements. By calculating the standard deviation, the sensitivity of the improved proton magnetometer is 0.15nT for Earth’s magnetic field observation. Experimental results show that the new magnetometer is sensitive to earth field measurement.
Comparison of a Designed Scalar Proton Precession Magnetometer with a Scalar Calibrated 3-Axis Fluxgate Magnetometer
This paper proposes the basic theory of the Larmor precession effect and A low noise earth field proton precession Magnetometer (PPM) design is implemented and a scalar calibrated 3-axis Fluxgate magnetometer is introduced. In the end, a Scalar earth magnetic field measurement Comparison between Our designed PPM and Our calibrated 3-axis Fluxgate Magnetometer (Using 3 single-axis FLC100 Magnetometer manufactured by Stefan Mayor Company) is done. Our proposed 3-axis Fluxgate Magnetometer consists of 3 single-axis FLC100 which are exactly perpendicular to each other with many mechanical efforts and is well-calibrated with 3-axis Helmholtz Coil and Scalar algorithm. Our calibrated 3-axis Fluxgate and Our designed PPM is calibrated based on magnetic earth measurement around 50000nT.
Energy
Energy is often defined as the ability to do work. There are many forms of energy. A few examples include; Gravitational energy, Kinetic energy (energy of motion), Thermal energy (heat energy), Potential energy. Potential energy is the energy something has based on its position in the universe. A stretched elastic band has potential energy. A rock held up in the air has potential energy based on its position.