SU1436084A1 - Seismometer - Google Patents

Abstract

The invention relates to geophysical instrumentation, can be used in seismometers and gravimeters. The aim of the invention is to reduce the temperature errors of the seismometer by reducing the temperature drift of the pendulum suspension containing inert mass 1, elastic hinges 3,4,5, spring 6, stand 7. As a result of a change in temperature of the stand or spring, which is detected by sensor 10, an additional moment of driving force acts on the suspension. To compensate for this, a temperature sensor is included in a bridge circuit 11–14, the imbalance of which causes a current in the winding 17 of the magnetoelectric converter and a deviation of the model proportional to the temperature drift. The value of the decoupling resistance is chosen based on the ratio R, j oi.KG/ (MRge), where Rj, is the value of the isolating resistor; ci - coefficient i (L

Description

bridge conversion ent; K is the gain of the scale amplifier; G is the electrodynamic constant of the magnetoelectric converter; M is the mass of the tiger; g is the acceleration of the force of gravity; R is the distance from the axis of rotation to the center

the tins of the titan; - temperature coefficient of linear expansion of the material of the stand, for the spring 5 X -, where y is the temperature coefficient of the shear modulus of the spring material; - temperature coefficient of linear expansion of the spring material. 1 il.

1 The invention relates to geophysical instrumentation and can be used in seismometers, gravity, i | ieTpax.

; The aim of the invention is to reduce the temperature errors of the seismometer by reducing the temperature drift of the pendulum suspension,.

The drawing shows a diagram of a seismometer.

The rotor suspension contains an inert mass 1, a farm 2, elastic hinges 3-5 and a cylindrical spring 6 mounted on a rack 7. On the base 8 there is a magnetoelectric transducer 9, the kit of which is fixed on the farm of the math. A temperature sensor 10 is mounted in the body of the tiller rack using a screw made of the same material as the rack, which is attached to the end of the screw and has good thermal contact with the base. The sensor can be attached to the spring with epoxy glue. A temperature sensor is included in one of the arms of a bridge circuit 11-14 at the rokhod of a differential scale amplifier 15 connected via a resistor 16 with a winding 17 of a magnetoelectric converter.

The seismometer works as follows.

With small angular deviations of the tambourine with zero initial length of the suspension cylindrical spring from the equilibrium position, it is affected by the sum of the moments Mj (b) of the elastic force Mp (b) and the gravity force mdSb)

Me (0) Mp (e) + Mj (0) Pry-Prx0-MRg, (1)

where P is the spring stiffness;

g is the distance from the axis of rotation to the point of the articulated joint of the spring with the farm of the swing-plate;

b - angle of rotation of the tandem; y, x - coordinates of the hinge connection

springs with stand; R is the distance from the axis of rotation to the center of gravity of the iron M; the mass of the iron; g is the acceleration of the force of gravity. For the zero position of the tangent (b 0 and Mj. (C) 0) from expression (1) we obtain

Uv

MRg

RG

(2)

When the temperature of the rack or the tangent spring on the DT changes as a result of their thermal expansion, an additional moment of force is generated.

five

. yMr, 30 where y is the increment of the coordinate.

(3}

 - temperature coefficient of linear expansion of the rack material. Movement of the tiger under the action

Forcing moment is described by diff

by the fermental equation

dluit, o.4.dASt dt2

. 2D., Sp. (four)

where n is the cyclic frequency of the eigen oscillations of the tomb; D - attenuation constant i

Ig is the length of the tomb.

From equation (4), we obtain the frequency dependence of the angular deviation & 9. temperature variation

.(five)

lc, (- Co2 + i2Dnco + nM

where CO is the current frequency.

At the same time, a change in temperature D.T. causes a voltage unbalance of the bridge circuit with a sensor 10 of the temperature, after amplification of this voltage by a large amplifier 15, in the winding.

17 magnetoelectric transducer; 15 cut-off resistor, magnitudes. a current i appears, the appearance of which leads to a deviation of a magnet at an angle U01

whose rank is chosen based on the ratio

  ot-K G M-R-gE

u9;

eLKGbX

K- () (- o2 + i2Dn 0+ n2)

EDS

k. where el, is the conversion factor J K is the gain factor of the large-scale amplification resistance and resistance of the converter winding,

moment of inertia of the tilt: The condition for compensation of forced tilting of the tilting due to changes in the temperature of its stand or spring is the equality lb U0-. Equating (5) and (6), we obtain an expression for finding the resistance of the disconnection R ,,

R

to.

oCKG MRgS

Claims (1)

Invention Formula A seismometer containing a pendulous suspension with a spring of inert mass. . 1436084 resistant and elastic hinges, as well as a magnetoelectric transducer and thermal compensator, I distinguish Sch and with the fact that, in order to reduce the temperature errors of the seismometer by reducing the temperature drift of the pendulum suspension, the thermal compensator contains a temperature sensor located in the body of the rack or on the spring and included in the bridge circuit at the input of the large-scale amplifier whose output is connected to the winding magnetoelectric converter, pc15 cutoff resistor, 20 25 30 gg 40 whose rank is chosen based on the ratio   ot-K G M-R-gE where R is the value of developing resistor, oL - conversion factor the bridge; K is the gain of the scale amplifier; G is the electrodynamic constant of the magnetoelectric converter; M is the mass of the tiger; g is the acceleration of the force of gravity; R is the distance from the axis of rotation to the center of gravity of the iron plate; - temperature coefficient linear expansion of the rack material; for the spring H where Y is the temperature coefficient shear modulus of spring material  - temperature coefficient of linear expansion rod.