The magnetic field is one of the main causes of zero drift in a Ring Laser Gyroscope (RLG), which should be avoided by adopting a magnetic shielding system. The Gauss Meter is usually used to measure the magnetic shielding effectiveness. Generally, the traditional Gauss Meter has advantages of high measure range and high reliability, however, its drawbacks such as complex structure, high price and the PC client software cannot be customized at will, are also obvious. In this paper, aiming at a type of experimental magnetic shielding box of RLG, we design a new portable three-axis magnetic field measurement system. This system has both high modularity degree and reliability, with measuring range at ±48Gs, max resolution at 1.5mGs and can measure the magnetic field in x, y and z direction simultaneously. Besides, its PC client software can be easily customized to achieve the automatic DAQ, analysis, plotting and storage functions. The experiment shows that, this system can meet the measuring requirements of certain type of experimental magnetic shielding box for RLG, meanwhile, for the measurement of some other magnetic shielding effectiveness, this system is also applicable.
Magnet outside is one of the main reasons that induce the bias shift of the Ring Laser Gyroscope (RLG), and the
most effective way to handle it so far, is to employ a magnetic shielding device. In this paper, we design a new magnetic
shielding box for RLG in Fe-Ni soft magnetic alloy. By 3-D modeling and simulation calculation in finite element
method, we plot the distribution of magnetic flux density of the box in uniform magnet; Besides, distribution of magnetic
shielding effectiveness (SE) on the gaining plane of RLG where is most sensitive to the change of magnet outside, is
given out, too. We also discuss the factors that influence the distribution of SE such as permeability of shielding material,
the thickness of the box and punching on the surfaces of the box. And by the SE test of the box samples, the result of the
simulation analysis was finally proved true. The result shows that, the structure of the box decides the distribution of SE
in it and the permeability of the material plays the predominant role in evaluating the average value of SE. Punching on
the surfaces of the box makes the distribution of SE severely inhomogeneous, and with increase of the permeability, the
influence will be more significant. At last, we put some practical steps forward to enlarge the average value of SE, and
these measures are also applicable in other similar magnetic shielding devices.