RU2025670C1 - Vibration meter - Google Patents

Abstract

FIELD: vibration measuring. SUBSTANCE: vibration meter has a microwave generator, detector with indicator connected to the detector, antenna connected in series, the antenna being disposed according to the expression given in the invention description. EFFECT: enhanced efficiency. 4 dwg

Description

 The invention relates to vibrometry and can be used as a vibration meter.

 Known vibration meter [1], containing a microwave generator, a double waveguide T-shaped bridge, an antenna, an adjustable load and a detector with an indicator. The operation of the meter is based on the imbalance of the bridge, which occurs when the controlled object is moved.

 The disadvantages of this meter are low sensitivity, the complexity of balancing the bridge.

 A vibration meter [2] is also known, which contains a three-arm circulator, to which a microwave generator is connected to one shoulder, an antenna to the other, and a detector with an indicator to the third. A pin is located between the antenna and the circulator in the waveguide, which forms the reference signal. The operation of the device is based on a comparison of the reference signal and the signal reflected from the vibrating object.

 The disadvantage of this device is its low sensitivity, complicated adjustment.

 Also known is a vibration meter [3], comprising a transmit-receive antenna included in the frequency-setting circuit of a microwave generator. The operation of the meter is based on the dependence of the mode of oscillation generation on the influence of waves reflected from a vibrating object.

 The disadvantage of this device is the low sensitivity due to its design.

 Closest to the invention is a device [4] containing a series-connected microwave generator, a detector with an indicator connected to it, and an antenna.

 The signal emitted by the detector is proportional to the displacement of standing waves in the transmission line, which implies the low sensitivity of the meter.

 The objective of the invention is to increase the sensitivity of the measurement of vibration of the controlled object.

+

=

+n где l₁ - расстояние от антенны до генератора;
l₂ - расстояние от антенны до контролируемого объекта;
λ_в- длина волны в линии передачи;
λ_o- длина волны в свободном пространстве;
n = 0,1,2...This is achieved by the fact that in a vibration meter containing a series-connected microwave generator, a detector with an indicator connected to it and an antenna, the latter is positioned taking into account the ratio

+

=

+ n where l ₁ is the distance from the antenna to the generator;
l ₂ is the distance from the antenna to the controlled object;
λ _in - wavelength in the transmission line;
λ _o - wavelength in free space;
n = 0,1,2 ...

 In FIG. 1 shows a block diagram of a vibration meter; figure 2 is a graph of the current quadratic detector on the distance between the detector and the object; figure 3 - dependence of the change in the frequency of the generator from the distance between the generator and the object; figure 4 - change in the current of the detector when the frequency of the generator.

 The vibration meter contains (Fig. 1) a microwave generator 1, a detector 2 with an indicator 3 connected to it, and an antenna 4 connected in series with a rectangular waveguide.

 The meter works as follows. The signal generated by the generator is emitted by the antenna, reflected from the controlled object and received by the same antenna. As a result of interference of direct and reflected waves, a standing wave forms in the transmission line.

n < l <

+

n, n = 0,1,2..., то увеличение расстояния между детектором и объектом приводит к увеличению тока детектора, а уменьшение этого расстояния - к уменьшению тока детектора. Если

+

n < l <

+

n , увеличение расстояния между детектором и объектом ведет к уменьшению тока детектора, уменьшение - к увеличению тока детектора.As can be seen from the graph in figure 2, if

n <l <

+

n, n = 0,1,2 ..., then an increase in the distance between the detector and the object leads to an increase in the detector current, and a decrease in this distance leads to a decrease in the detector current. If

+

n <l <

+

n, an increase in the distance between the detector and the object leads to a decrease in the detector current, a decrease in to an increase in the detector current.

+ λn , то увеличение h ведет к увеличению частоты, уменьшение h - к уменьшению частоты. Соответственно, если h = λn, увеличение h приводит к уменьшению частоты, уменьшение h - к увеличению частоты.The displacement of the object leads to a change in the frequency of the generated signal by pulling the frequency. From the graph in figure 3 it is seen that if h =

+ λn, then an increase in h leads to an increase in frequency, a decrease in h leads to a decrease in frequency. Accordingly, if h = λn, an increase in h leads to a decrease in frequency, a decrease in h leads to an increase in frequency.

n < l <

+

n , увеличение частоты приводит к увеличению тока детектора, если

+

n < l <

+

n , увеличение частоты приводит к уменьшению тока детектора. Соответственно уменьшение частоты приводит к обратной ситуации.As can be seen from figure 4, a change in frequency leads to a change in the current of the detector. If

n <l <

+

n, an increase in frequency leads to an increase in detector current if

+

n <l <

+

n, an increase in frequency leads to a decrease in the detector current. Accordingly, a decrease in frequency leads to the opposite situation.

 As can be seen from the above, a change in the position of the object leads to a change in the detector current through two factors: the displacement of the standing waves, the change in the frequency of the generator, which also leads to the displacement of the standing waves, due to the change in the wavelength.

+ n

, где n = 0,1,2....Thus, by choosing the distance from the generator to the object, the summation of the detector current changes due to the factors listed above is achieved. This distance is selected from the ratio:
h =

+ n

where n = 0,1,2 ....

+

=

+ n, где l₁ - расстояние между генератором и антенной;
l₂ - расстояние между антенной и контролируемым объектом;
λ_в- длина волны в линии передачи;
λ_o- длина волны в свободном пространстве,
n = 1,2,0....Since the wavelength in the transmission line does not always coincide with the wavelength in free space, we rewrite the relation in the following form:

+

=

+ n, where l ₁ is the distance between the generator and the antenna;
l ₂ - the distance between the antenna and the controlled object;
λ _in - wavelength in the transmission line;
λ _o - wavelength in free space,
n = 1,2,0 ....

PRI me R. To measure vibration, use a microwave generator with an oscillation frequency of 18.3 GHz and an external Q factor of 300, as a detector - a diode D608, an indicator-oscilloscope C1-93, antennas - the open end of a rectangular waveguide. A rectangular waveguide with a cross section of 11 x 5.5 mm ^{2 is} used as a transmission line. Measurements showed an increase in the sensitivity of the claimed device by 70% compared with the prototype (290 μA / mm versus 190 μA / mm).

 The use of this device allows for high-precision, precision measurements of the parameters of mechanical vibrations, which opens up wide possibilities for its application in various fields of the national economy.

Claims (1)

VIBRATION METER, comprising a microwave generator in series, a detector with an indicator connected to it, and an antenna, characterized in that, in order to increase the sensitivity of vibration measurement of a controlled object, the antenna location is determined from the ratio

+

=

+ n,
where l ₁ is the distance from the antenna to the generator;
l ₂ is the distance from the antenna to the controlled object;
λ _in - wavelength in the transmission line;
λ _o - wavelength in free space;
n = 0,1,2 ....

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