Preliminary Results of Total Field Magnetometer Comparison

1. Preliminary Results of Total Field Magnetometer Comparison Introduction During the XIVth IAGA Workshop (hereafter referred to as “the workshop”), several total field comparison measurements were conducted at the Changchun Magnetic Observatory (CNH). The purpose of these tests was to look for errors within the total field instruments which are considered “absolutes” instruments. The total field measurements is a critical component of the absolute measurement computation. Samples between two total field sensors, corresponding in time, were directly compared. Other methods for calibration exist for these sensors, including the use of frequency generators. Method The participants were Dr. Hans-Joachim Linthe from Germany, Haizhi Liu, Guihua Qi, Fuxi Yang and Suqin Zhang from China. Table 1 summarizes the testing specifications for each participant’s system. Frequency Test Table 3: Proton Magnetometer Frequency Test of GSM19 Table 1: Instruments and testing specifications Table 4: Proton Magnetometer Frequency Test of G856AX Data collected by the test systems were directly compared to the corresponding samples collected by the GSM-90 Overhauser magnetometer at Changchun Observatory with 1Hz sampling rate. Data Table 2 presents the mean values and standard deviations for each system. Table 5: Proton Magnetometer Frequency Test of G856T(26#) Table 2: Pier difference (ΔF) results Table 6: Proton Magnetometer Frequency Test of G856T(27#) The pier difference (ΔF) was plotted for each system, see Figure 1. Table 7: Summary of Proton Magnetometer Frequency Test Figure 1: Pie difference for each system Figure 2: Second data curve of GSM-90 at Changchun Observatory in observation period