SU693325A1 - Gravitational variometer - Google Patents

Description

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The invention relates to the field of gravimetry and can be used to measure the weak forces of a gravitational, electromagnetic, or other nature.

A device is known that includes a housing, an optical device, a recorder, a torsional torsion, executed in the form of a rocker arm with test masses fixed at its ends and suspended by a midpoint on a thin elastic twisting filament ij.

In this device, under the influence of microseisms and inertial accelerations of a different nature (vibrations, shocks, etc., parasitic oscillations of the rocker arm occur relative to the upper point of the suspension (swingar vibrations) and relative to the lower point of the suspension (swing), which lead to nazgoyemoe dynamic stiffness. The stiffness of the torsional thread increases, which accordingly leads to a change in the period of torsional oscillations of the rocker arm.

Experimental studies on the measurement of the gravitational constant show that the seismic effects on the rocker determine the stability of its oscillation period at the level of

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which is a significant obstacle to improving the accuracy of measurements,

A variometer is known, comprising a housing, an optical device, a recorder, a torsion tick made in the form of a cross-shaped symmetric rocker, whose center of gravity coincides with the point of the suspensions. Optimization of the design and parameters of the sensing element allows to increase the stability of its period to

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10 -f10The complexity of the nonlinear theory of the movement of the rocker does not allow us to find an exact solution, and therefore there is no possibility of strictly solving the optimization problem. In addition, it is possible to take into account systematic errors caused by the nonlinear character of the theory of the motion of the dial and the influence of interference. The closest to the present invention is the ethves gravitational variometer containing two torsion mats with the same moments of inertia suspended on a common base on elastic strands with the same torsional rigidity, housing, optical reference system, rotary azimuth device f 3. The specified variometer It has low accuracy, it exhibits systematic errors due to the influence of interference. The purpose of the invention is to improve the measurement accuracy by eliminating the effect of random interference due to inertial accelerations of the base of the instrument. The goal is achieved by the fact that one of the torsion bodies is made in the form of a body with a uniform angular distribution of mass in the plane of rotation (i.e. it has the shape of a body of rotation), for example, in the form of a cylinder suspended so that its axis coincides with the axis of rotation twisting thread. By properly placing the mirrors of the tickmans, the optical subtraction of the rotation angles of the tillers is carried out. Since both tillers have the same moments of inertia with respect to the suspension point, they will be equally affected by inertial noise. But at the same time, a cylindrical tambourine, having an evenly distributed mass relative to the axis of rotation, will not react to moments of gravitational forces, and an ordinary trough made in the form of a dumbbell will also sense a change in the moments of gravitational forces. Consequently, the difference in the periods of these two masters will be free from the influence of inertial interference. FIG. 1 schematically shows the proposed device; in FIG. 2 is a schematic diagram of it. The gravitational variometer contains a gravity sensitive tandem 1, a gravity sensitive tandem 2, resilient hangers 3, an illuminator lamp 4, an optical system 5, auxiliary mirrors b, a photo receiver 7, a luminaire lamp of the bodies of the lower mirrors 8, coordinate-sensitive components 9, lower mirrors a 10, photoana, 1i: ito ;; s AND, prisms 12, and aphragms 13 (rotational azimuth, the device is not shown in the figure). Gravity-sensitive tandem 1 can be made in the form of a dumbbell with masses, akpleyinp and at the ends of the horizontal rod. The gravity sensitive antenna is made in the form of a symmetric body, for example, a cylinder, a sphere, a cone, etc., and the axis of the body of rotation must coincide with the axis of the suspension of the tandem. Mirrors 6 implement an angled reflector, which transmits the light beam from the lamp to the illuminator 4 through the optical system 5 to the photodetector 7 only at times that are multiples of the periods of both receivers. In this case, the photodetector registers the memory transfer of satanics through the equilibrium position, and the period of the difference waveform is equal to the difference of the periods of the source waveform. It is also possible to measure the period of each tambourine separately, and form the difference between the periods in the registration system. In this case, the contribution of non-gravitational disturbances is also eliminated from the period of oscillation of the gravitational sensitive (the device for such registration does not require any special explanation and is not shown in the drawing). The position of each tambourine in the horizontal plane is fixed by means of coordinate-sensitive photovoltaic cells. For this purpose, the beam of light JOT of the lamp 8 is directed through the prisms 12, diaphragm 13 and the holes in the center of the photocells to the lower mirrors Y. Reflected from the mirrors, the light beam with a diverging beam falls on the active surface of the photocells 9. When there is no oscillation and swinging, (in the absence of macro- and macroseism), the magnitude of the difference photocurrent of the photomultipliers 9 (with correct horizontal installation of the lower mirrors of Yu) is zero. Torsional vibrations: there will be no influence on the value of the differential photocurrent of the receivers 9. Thus, the photodetectors 9 provide an additional opportunity to monitor the conditions under which measurements are made, and to amend the measured values. The effect of the variometer is as follows. Lamps 4 and 8 are turned on at the observation point. Then the master figures are asked. 569 torsional vibrations in different directions: one clockwise, and the second one against. The time between the moments in which the photodetector 7 will register the signal of the coincidence of the pilot signals will correspond to the difference period of the oscillations of the pilot waves. The use of an equilibrium model in conjunction with conventional gravity makes it possible to reduce systematic and random errors due to seismic and microseismic interference. This makes it possible to increase the accuracy when measuring in static and, especially, in dynamic modes. When using a variometer in the dynamic mode, its projeyvrGyAyyness increases by 5-6 times compared with the static mode of measurement with equal (about 4OO s) own periods of oscillation. The use of the pre-vario in field conditions P01 etolit significantly reduces the requirements for taking into account temperature effects, since they will be automatically eliminated during the measurement process. The proposed variometer, in addition to the small forces of gravity on the origin, can be used for small forces due to magnetism, light pressure, and ultrahigh frequencies. In this case, the measurement accuracy is increased by the order of magnitude.

Claims (3)

(pu 56 Formula of the Invention 1. A gravitational variometer containing two torsion mounts with the same moment of the nines suspended on a common basis on elastic threads with the same torsional rigidity, which is equal to < t & excluding random systematic interference; in it one of the torsion tillers is made in the form of a symmetrical body with a uniform angular distribution of mass in the plane of its rotation, and its axis of symmetry coincides with the thread of the suspension. 2. The variometer in accordance with claim 1, which is one with the fact that one of the torsion bags is mounted in the form of a cylinder. Sources of information accepted by Vshmannyo during the examination 1. Kalinnikov I. I., Kolosnidyn N. I. To the theory of horizontal scales with six degrees of freedom. Sat Questions of standardization, metrology and precision measurement techniques. M., Ed. standards, 1973. p., 219-224.,. 2. Anikin, V.I., et al. Torsion scales for measuring Cavendish by constant. Sat The questions are Stavdart Zash, metrologin and exact WAM. :. standards, 1973, p. 224-230. 3. Ivsev K. E., Sag. M. U. Gravimetric intelligence, M., Nedra, 1968, p. 212-230.