SU381039A1 - DEVICE FOR MEASUREMENT OF MECHANICAL - Google Patents

Description

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The invention relates to electrovacuum technology and can be used to create devices for measuring the intrinsic resonant frequencies of microelements of vacuum products.

Devices are known for measuring the resonant frequencies of mechanical oscillations of products using the method of passing microwave energy, comprising a mechanical oscillator, a sensitive element that converts mechanical oscillations into an electrical signal, and an electrical signal frequency meter. To measure the resonant frequency, the element under study is placed inside a high-quality microwave resonator, which is difficult to implement. Therefore, the number of parts that can be investigated using a known device is limited.

The aim of the invention is to simplify the device, increase the measurement accuracy and reduce the restrictions on the size and weight of the products under investigation.

This goal is achieved by using a volumetric cavity tunable in a wide range with a built-in antenna connected with a microwave oscillation source as a sensing element, near which the test article is stirred on the outside of the resonator. The output of the resonator is loaded on the absorbing element and the detector head, to the output of which a spectrum analyzer and an oscilloscope are connected.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 - resonator with anthemic.

The device contains a microwave generator /, ferrite valve 2, attenuator, directional coupler 4. diaphragm 5, tunable resonator C, detector head 7, absorbing load S, vibrator 9, oscilloscope 10, spectrum analyzer // and resonating element 12.

The resonator includes a waveguide 13, a micrometer screw 14, a piston 15, a flange 16 and an antenna P.

The device works as follows. The generated microwave signal of the centimeter range, pass valve 2, attenuator 5 and coupler 4, falls into a hollow resonator. The resonator is a waveguide section, which is limited to 1P1YY on the one hand by the diaphragm 5 with a communication gap, and on the other hand by the short-closed piston 15 allowing the resonator to be rearranged in a rather wide range. The resonator is the main sensitive element of the device that converts mechanical vibrations into an electrical signal.

The microwave signal is reflected from the piston 15, at a certain position of which the resonator

tuned to resonance. The resonator is tuned with a micrometer screw 14. The tuning indicator is an electron-beam oscilloscope 10, the screen of which receives the low-frequency envelope of the microwave signal from the detector head 7.

A feature of the resonator is the presence of an antenna 17 located inside the resonator in that part of it, in which there is a maximum microwave field strength. The antenna allows the microwave field to be output, near the hole in the resonator, which is concentrated between the end of the antenna pin and the wall of the resonator and has a large gradient in this part of the space. The element under study is inserted into this part of the space and the resonator is adjusted. The resonator has a wide range of adjustment, thanks to which it is possible to investigate elements that vary in size and configuration.

The element under study is mechanically connected with an electrodynamic or piezoelectric vibrator 9, which excites resonant oscillations in it. During the investigation, the vibration frequency smoothly changes, and when resonant oscillations of the element occur, the amplitude of the latter increases. When this occurs, a periodic detuning of the resonator occurs, resulting in amplitude modulation of the transmitted microwave power. Modulation is observed with a spectrum analyzer after preliminary detection of the microwave energy.

The device has a high sensitivity, which allows to measure the resonant

Mr. Ochastota of various elements, including miniature and microminiature elements in the frequency range up to 20 kHz and above. The possibility of locating the elements under study outside the resonator is a significant advantage of the device and largely determines its performance. The wide range of resonator tuning and ease of setup allows the device to be prepared for operation easily and in a short time and provides an opportunity to explore various elements of arbitrary configuration, weight and dimensions.

Subject invention

A device for measuring mechanical resonant frequencies of miniature and microminiature elements, comprising a generator connected in series, a ferrite valve, an attenuator, a directional coupler and a diaphragm, as well as a vibrator, characterized in that

and simplify the measurement, it is equipped with an absorbing element, an oscilloscope, a detector head, a spectrum analyzer, an antenna and a tunable cavity resonator switched on at the output of the diaphragm, with

This antenna is built into the resonator, and near it, from the outside of the resonator, the test element mechanically connected to the vibrator is placed, and the output of the resonator is loaded onto the absorbing element and the detector

a head to the output of which a spectrum analyzer and an oscilloscope are connected.

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