SU371456A1 - - Google Patents

Description

METHOD OF MEASURING FLEXIBLE DISC VIBRATIONS

one

The invention relates to the field of measurement technology.

Methods are known for measuring vibrations by determining displacements at two points located in close proximity to one another along one line, and a corresponding conversion of the values obtained.

The proposed method makes it possible to measure the vibrations of a flexible disk, excluding the error in measuring the amplitude of oscillations from its skew and axial displacements. This is achieved by measuring the displacements simultaneously at three points on the same line: in the middle of the disk, the extreme point, the amplitude of oscillations of which is determined, and between them. The last measurement is multiplied by the ratio of the distance between the extreme points with the distance between the point in the middle of the disk and the intermediate point, and the value obtained is subtracted together with the amount of displacement in the middle of the disk from the value of the displacement at the edge of the disk.

Figure 1 shows a circuit for measuring. The disk 1 oscillates during rotation. (Skew, axial displacement X and oscillation X). To determine the oscillation 3, excluding the skew error a, and the displacement Xi measure the displacement at three points: in the middle of the disk by sensor 2, intermediate by sensor 5 and at the extreme point, the amplitude of oscillations of which is determined by sensor 4. The signal from sensor 3 is multiplied by device 5 to the ratio kjh, where k is the distance between the extreme points of measurement, and ft is the distance from the point in the middle to the intermediate point. The resulting value together with the measurement value in the middle of the disk is subtracted in the device 6 from the measurement value at the extreme point. Left with

the value corresponds to the amplitude of oscillation 3. The measurement value of sensor 2 corresponds to the axial displacement X, and the measurement value of sensor 3 (Xo), multiplied by k / h, corresponds to the skewness a and expresses the value Xz.

Usually the middle part of magnetic disks is relatively hard. Sensors 2 and preferably placed on the hard part of the disk /. However, the possible slight elastic

the rigid part oscillations practically do not affect the measurement value, since the sensors 2 and 5 are at a close distance in comparison with the distance between the sensors 2 and 4.

25

Subject invention

Method for measuring vibrations of a floppy disk

by determining the displacements at two points,

30 located in close proximity

from one another along a single line, characterized in that, in order to reduce the error in measuring the amplitude of oscillations of a given point, for example, the edge of the disk, the offset at the extreme point is additionally determined and the measured value at the intermediate point between the middle and the edge of the disk is subtracted from the obtained value multiplied by the ratio of the distance between the extreme points to the distance between the point in the middle of the disk and the intermediate point, together with the amount of displacement in the middle of the disk.