SU1620945A1 - Horizontal vibration-testing machine - Google Patents

Abstract

This invention relates to a measurement technique. The aim of the invention is to improve the accuracy of determining the transverse sensitivity coefficients for vertical accelerometers with input calibration accelerations less than 0.1 m / s2. After being placed on the calibration zibroplatform 1 of the calibrated 3 and reference 4 accelerometers, adjusting the regulator 8 with the gain factor of the reference accelerometer 4. 4. It has the same sensitivity as the accelerometer 3. At the same time, due to the fact that the signals from accelerometers 3 and 4 are the same in the absence of a calibration effect, since the vines are affected only by tone vibro noise, and, subtracting, they are aimno compensate each other. Then, an excitation mechanism 2 is switched on, with the help of which the vibroplatform 1 and accelerometers 3. 4 set horizontal accelerations with an amplitude of no more than 0.1 m / s. In this single reading, measure 9 is determined only by the transverse sensitivity of the calibrated accelerometer 3, since all other components of its output voltage are compensated by signals from the operative accelerometer 4. 1 Il.

Description

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The invention relates to a measurement technique, in particular, to methods and means for certifying and calibrating transducers of parameters of mechanical movements into an electrical signal.

The purpose of the invention is to improve the accuracy of determining transverse sensitivity coefficients for vertical accelerometers with input calibration accelerations less than 0.1 m / s.

The drawing shows a block diagram of a horizontal shaker.

The vibrostand consists of a calibration vibroplatform 1, which is associated with the excitation mechanism, which gives it variable accelerations in the horizontal plane. Platform 1 has a graduated accelerometer 3, the measuring axis of which is oriented vertically, and a reference accelerometer 4 with a liquid inertial mass 5 placed inside a spherical piezoelectric sensing element 6. At the same time, the output of a graduated accelerometer 3 is connected to the input of a differential amplifier 7 with an adjustable gain factor, and the output of the reference accelerometer 4 is connected to the inverting input of the amplifier 7 through the regulator 8 of the division factor. The voltage at the output of amplifier 7 is measured by a meter 9 connected to it.

With the help of mechanism 2 platform 1 sets the variable acceleration in the horizontal plane. It can be made either as a conventional directional vibrator with a horizontal axis of force, or as a double centrifuge with a vertical axis of rotation.

The differential amplifier 7 subtracts from the output signal from the graduated accelerometer 3 an in-phase signal from the reference accelerometer 4 whose design provides, at small levels of input influences, the measurement of only the vertical component of the vibrational acceleration. The relative transverse sensitivity coefficient of the additional accelerometer 4 has a value of Kp ar / 2d, where ar is the horizontal acceleration value; g - free fall acceleration. With ag 0.01 g (0.1 m / s), the suppression of the components of the output signal, due to the presence of a kn in it, is not less than 46 dB and increases with decreasing ag. At the same time, the sensitivity of the reference accelerometer 4 is not

five

0

5 0 5 0

35

40 45 50 55.

varies with the value of the input graduated action.

The vibration table works as follows.

After placing on calibrated vibroplatform 1 calibrated 3 and reference 4 accelerometers, adjusting the gain 8 via the regulator 8 through the reference accelerometer channel 4, it is set to have the same sensitivity as the accelerometer 3. In this case, the minimum value of the output voltage on the amplifier 7 is reached. that the signals from accelerometers 3 and 4 are the same in the absence of a grounding effect, because they are affected only by background vibro-noise, and when subtracted they are mutually ompensiruyuts.

Then, an excitation mechanism 2 is turned on, with which the vibroplatform 1 and accelerometers 3 and 4 set horizontal accelerations with an amplitude of not more than 0.1 m / s. In this case, the readings of meter 9 are determined only by the transverse sensitivity of the calibrated accelerometer 3, since all the remaining components of its output voltage are compensated by signals from the reference accelerometer 4, the transverse sensitivity of which at ar 0.1 m / s2 is obviously less than any other of the known accelerometers.

Claims (1)

Invention Formula A horizontal shaker containing a base, a calibration vibroplatform on an elastic suspension on which a graduated accelerometer is mounted, and a mechanism for exciting its oscillations in a horizontal plane, so that, in order to improve the accuracy of determining transverse coefficients sensitivity of vertical accelerometers at levels of input gravity accelerations less than 0.1 m / s, a reference accelerometer is inserted in it, made with a spherical piezoelectric sensing element, a liquid inertial mass, and a differential amplifier with adjustable gain along one of the channels, one input of which is connected to the output of the reference accelerometer and the other to the input of the calibrated accelerometer, and the reference accelerometer is placed along with the calibrated accelerometer on the vibroplzform.