SU1599779A2 - Method of determining lower border of dynamic range of piezoaccelerometer - Google Patents

Abstract

This invention relates to a measurement technique. The aim of the invention is to enhance the functionality by controlling the lower limit of the dynamic range. According to the method, one of the supports is shifted relative to the edge of the platform until the lower limit of the dynamic range of the accelerometer coincides with the operating frequency range reproduced on the stand. 2 Il.

Description

The invention relates to a measuring technique and is intended for calibration of piezo accelerometers.

The purpose of the invention is to expand ... functionality by providing adjustment of the lower limit of the dynamic range (IGHD),

Figure 1 shows the frequency response of the vibration signal of the accelerometer; Fig. 2 is a block diagram of a measurement path for determining an NGDC accelerometer.

A device for determining the NGDD of a piezo accelerometer consists of a platform 1, a rigid body fixed on two supports, one of which, for example 2, is fixed "

A piezo accelerometer 3 and an exciter 4 with a dynamic force sensor 5 are mounted on the platform between the two supports. Piezo accelerometer 3

and a dynamic force sensor 5 is installed in close proximity to each other. The output of the dynamic force sensor is entered as negative feedback into the exciter excitation circuit 6 and connected to its control input. Bearing 7 is movable and shifted relative to the edge of the platform. Bearing 7 is connected through bolts 8 and screw 9 with the stand lOt

The lower limit of the dynamic range of the accelerometer being tested is defined as follows.

The test accelerometer 3 is installed on a rigidly fixed platform I. Platform oscillations are excited in the immediate vicinity of the piezo accelerometer using the vibration exciter 4c if the piezo accelerometer and the dynamic force sensor are located in the immediate position

with so

v3

with

hch

Their output signals are related to each other with a different linear relationship, I where the coupling factor is the static deformation of the platform. To maintain the amplitude of the vibration-stimulating force, a constant signal from the output of the dynamic force sensor 5 is fed back to the output of the vibration locomotive 1 of the driver. forces (Change from zero to the half-iHoro frequency of the first resonance of the platform, mounted on supports 2 and 7, and measure the frequency response at the output of the piezo-axle- / odometer / figo, curve 1) and mate and set frequency range If the mate point is aligned with a given frequency range, there must be a portion proportional to the frequency on the registered frequency response of the piezo accelerometer (in Fig. 1, this portion of curve 1 between the frequencies). If this segment is absent, the interface point is higher in frequency relative to the specified frequency range (interface point 3 in FIG.). If there is a linear portion in frequency response, which is proportional to the frequency, and there is a non-linear portion, OTCVTCTsyeT, then the pairing point is below the specified frequency range (the pairing point 2 in Fig. 1)

After finding the mutual position of the junction point and a predetermined frequency range, the system is converted so that the junction point is aligned with the specified frequency range, as follows.

If the interface point is above the specified frequency range,

the support 7 is given the bolts 8, with the help of the screw 9 they move the support to the edge of the platform (the platform stiffness decreases until the point of conjugation is consistent with the specified

frequency range

If the interface point is below the specified frequency range, bolts 8 are given on support 7, the platform support is moved to the center using screw 9 (the rigidity of the platforms increases until the interface point is aligned with the specified frequency range

Then, the ordinate of the nonlinear portion of the amplitude-frequency characteristic determines the lower limit of the dynamic range of the piezo-accelerometer. The non-linear portion of the amplitude-frequency-response characteristic is determined from it. deviation from the direct (when building the frequency response in the log {) if: - a scale of two axes,

Claims (1)

Invention Formula The method for determining the lower limit of the dynamic range of a piezo accelerometer according to its license No. 1254393, is due to the fact that, in order to expand its functionality by providing adjustment of the lower limit of the dynamic range, one of the supports is shifted relative to the edge of the platform with the operating frequency range reproduced on the stand "./ ft fv-flfi fj fiffj Fig, 1 ///// ///// r ////////////// . FIG. FIG.