SU1354148A1 - Vertical geophone - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the parameters of vertical oscillations in seismometry and vibrometry. The aim of the invention is to increase the sensitivity and noise immunity while reducing the weight of the vertical geophone. The seismic receiver is made in the form of two concentrically arranged piezoceramic spheres 2 and 3, the gap between which is filled with a heavy liquid inertial mass 4. The radial polarization of the spheres is mutually opposite, and the piezo transducers themselves are connected in parallel. Due to this, the received signal is doubled, and the interference caused by the pyro effect in piezoelectric ceramics is subtracted. The thickness of the gap between the spheres can be made small, which reduces the weight of the seismic receiver without reducing its sensitivity. 1 il. С (Л с с СП 4) 4 О)

Description

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The invention relates to a measurement technique and can be used to measure the parameters of vertical oscillations in seismometry and vibrometry.

The purpose of the invention is to increase the sensitivity and noise immunity while reducing the weight of the vertical seismic receiver.

The drawing shows a vertical seismic receiver, a general view.

The housing 1 contains a piezoelectric transducer element consisting of two concentrically located hollow piezoceramic spheres of the narzgzhnaya 2 and internal 3, which have opposite directions. radial polarization; The liquid inertial mass 4 is placed in the cavity between spheres 2 and 3. In this case, the inner lining 5 of the sphere 2 is electrically connected to the outer lining 6 of the sphere 3. The stopper 7 locks. opening for filling the liquid inertial mass 4. The electrical signal is taken from the outer lining 8 of the sphere 2 of the inner lining 9 of the sphere 3.

The seismic receiver works as follows.

When exposed to the acceleration receiver, the liquid inertial mass 4. Acts on the piezoelectric transducer elements 2 and 3 so that the pressure developed by the liquid inertial mass 4 is compressive for the inner sphere 3 (externally applied) and height for the outer sphere 2 (applied from the inside). The integral values of the mechanical stresses experienced by spheres 2 and 3 and determined by the values of the pressures acting on their surface, due to the small gap between spheres 2 and 3, are equal. The equality of mechanical stresses and the proximity of the geometrical dimensions of the spheres result in the appearance of almost equal electrical voltages on the plates 5, 8 and 9, 6. Here, due to the counter polarization of the piezoelectric spheres, the 2nd 3 on the plates 6 and 8 induce charges of one sign, and on the plates 5 and 9 of the other. Therefore, when the spheres 2 and 3 are connected in series, provided by the electrical connection of the plates 5 and 6, the resultant

The voltage removed from the plates 8 and 9 is equal to the sum of the electrical voltages on spheres 2 and 3.

Thus, when a vibrating acceleration seismic receiver is applied to its output, an electrical voltage is induced at its output, the magnitude of which is twice the voltage removed from the seismic receiver with a sensing element in the form of a single sphere in the same conditions. In addition, the sequential inclusion of piezoelectric elements with opposite polarization directions makes it possible to significantly reduce the effect of ambient temperature fluctuations on the seismic receiver, since electric charges induced by piezoelectric elements due to pyroelectric effect are subtracted from the proposed design, compensating each other. other, and do not pass on the output terminals of the geophone. The displacement of the liquid mass in the cavity between the spheres allows significantly (by a factor of 2-3) to reduce the total mass of the receiver. The concentric mutual arrangement of spheres 2 and 3 determines the identity of the characteristics of the geophone with an arbitrary placement of the body in space. This is also facilitated by a decrease in air volume in the cavity between the spheres, the presence of which only one goal pursues; protection of seismic receiver elements from mechanical damage due to the difference in the coefficients of the 4Q volumetric expansion factors of spheres 2 and 3 and the inertial mass 4.

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Claims (1)

The invention of the vertical seismic receiver, co. 45 holding the body and the first piezoceramic transducer installed in it in the form of a hollow radially polarized sphere, partially filled with a liquid inertial mass, characterized in that, in order to increase the sensitivity and noise immunity while reducing the weight of the vertical seismic receiver, it additionally contains gg is a second spherical piezoceramic transducer having pro-. opposite direction of radial polarization and installed centrally inside the first piezoceramic Formula of the invention Vertical seismic receiver, co. 45 holding the body and the first piezoceramic transducer installed in it in the form of a hollow radially polarized sphere, partially filled with a liquid inertial mass, characterized in that, in order to increase the sensitivity and noise immunity while reducing the weight of the vertical seismic receiver, it additionally contains gg is a second spherical piezoceramic transducer having the opposite direction of radial polarization and installed centrally inside the first piezoceramic 1354148 The transducer, and the liquid of the first piezoceramic pre-inertial mass is placed in the forming strip electrically connected between the piezoceramic transducer, with the outer lining of the second piezo transducer, while the internal ceramic transducer.