SU894339A2 - Device for electromagnetic measuring of deformation rate - Google Patents

Description

(54) DEVICE FOR ELECTROMAGNETIC MEASUREMENT

one

The invention relates to a measurement technique and can be used to measure the strain rate of products.

According to the main auth. No. 741038, a device for electromagnetic measurement of the strain rate is known, comprising a transmitter, two antennas connected to a serially connected mixer, an amplifier and a frequency meter.

The disadvantage of this device is that, when measuring the strain rate of products, the frequency meter records, in addition to the strain values, the parasitic components associated with the unstable operation of the mixer.

The purpose of the invention is to improve the measurement accuracy.

This goal is achieved by the fact that the device is equipped with two intermediate mixers, to the inputs of which each antenna is connected, the outputs of intermediate mixers are connected to the inputs of the main mixer, as well as two heterodyne, each of which is connected to the other inputs of intermediate mixers. DEFORMATION SPEED

The drawing shows the described device.

The device contains a transmitter 1, installed at points A and B of product 2, antennas 3 and 4, between which the deformation is measured. The outputs of the antennas 3 and 4 are connected to intermediate mixers 5 and 6, to the other inputs of which the heterodyne 7 and 8 are connected.

10 The outputs of intermediate mixers 5 and 6 are connected to the main mixer 9, connected in series with a C-amplifier 10 and a frequency meter 11.

The device works as follows 15 times. -.

The deformable product 2 is irradiated by electromagnetic waves with a frequency fp produced by transmitter 1. At points A and B of product 2,

20 between which it is necessary to measure the strain rate, receiving antennas 3 and 4 are installed, receiving electromagnetic oscillations with frequencies

25

  fO + Rdd and f fo + RdB

When the product 2 is deformed, the speeds of points A and B are different, respectively, Doppler shifts of frequencies Al received by antennas 3 30 and 4 are different. Signals from antennas 3 and 4 are mixed in intermediate mixers 5 and 6 with signals from local oscillators 7 and 8, the frequencies of which are f and fj-g are spaced apart.

Signals from intermediate mixers 5 and b with frequencies

5-H - p o - G7 + FAA

ffc - 4 V8 o - fre + Ab is fed to the input of the main mixer 9, where they are mixed. At the output of the main mixer 9, the difference frequency UF is allocated, which is amplified by the amplifier 10 and fixed by a frequency meter 11

  () + (: in-app)

AF

Thus, this device due to the presence of the component gz n allows to eliminate the ambiguity of fixing the values of the strain rate of the product 2.

Claims (1)

Invention Formula A device for electromagnetic measurement of the strain rate according to the auth. No. 741038, that is, in order to improve measurement accuracy, it is equipped with two intermediate mixers, to the inputs of which each antenna is connected, the outputs of the intermediate mixers are connected to the inputs of the main mixer, as well as two heterodyne, each of which is connected to other inputs of intermediate mixers. Sources of information taken into account in the examination , ,one. USSR Author's Certificate No. 741038, cl. G 01 B 7/16, 1978 prototype).