SU24485A1 - Instrument for testing magnetic materials for tempering and annealing - Google Patents

Description

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as a result, the generator frequency gets a new value of f. To enable readings (without changing the tension of the string), it is necessary that the frequency f be more than /. In the latter case, the frequency of the string can be brought into resonance with the frequency of the generator / by shortening the length L, moving the filly 6. By designating. A new string length, resonating at the oscillator frequency f, as we know, we get:

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Thus, changes in the value of self-induction due to a change in the magnetic properties introduced into the material coil 3 can be determined from the change in the length of the resonant string. The results of measurements in individual cases will be comparable to each other according to the relative amount of change in self-induction, if the initial frequency of the string is always tuned at a constant initial frequency to the generator for what, and the constant capacitances of 1 are used: naturally with self-induction 3 circuits. The difference between the proposed instrument and the one described in the main patent No. 1768 is reduced to the simplification of the electrical circuit and the whole instrument apparatus, which makes it possible to conduct measurements with greater simplicity and convenience.

The automatic recording of the instrument readings is possible with the inclusion of a generator into the oscillatory circuit through an amplifier of a recording frequency meter 8 (Fig. 2). In this case, the readings are recorded as follows. One of the constant capacitances 1 is introduced into the oscillator circuit of the generator, which, together with self-induction 3, sets the circuit to some initial frequency /, indicated by the frequency meter 8. If the test material is lowered into the roller 3, then the generator frequency will automatically be marked by a frequency meter. In the same way, it is possible to record changes in the magnetic properties of materials during the action of physical and chemical reagents on them. For the latter purpose, the material is introduced into the coil 3 and exposed to the action of the reactants. All material changes associated with changes in its magnetic properties as a result of the action of reagents will be indicated by a frequency meter.

To automatically record the instrument readings with small changes in the magnetic properties of the tested materials, use filter 10 (Fig. 3) included in the circuit of the last stage of the amplifier and tuned to the back frequency /, and relay 9 included in the anode circuit of the last stage. Obviously, any changes in the self-induction of the coil 3 will cause changes in the frequency of the circuit tuned to the frequency of the filter /, which in turn will cause sharp fluctuations of the anode current in the last stage of the amplifier, so that relay 9 will be activated. By including signal or writing devices in the relay circuit, automatic recording can be performed.

The subject matter of the invention.

Claims (2)

1.Vodoizmenenie instrument according to patent number 1768, characterized by the use of a recording frequency meter, included with the help of a cathode amplifier in the oscillatory circuit of the generator and noting the change in the oscillation frequency of the latter when the self-induced magnetic sample is introduced into the coil. 2. The device modification according to claim 1, characterized by the use of a filter included in the grid circuit of the last stage and tuned to a generator frequency corresponding to certain properties of the tested magnetic sample, with the aim that when a resonance occurs, the relay, including the signal, either recording device.