SU84572A2 - Device for determining the magnetic properties of various materials - Google Patents

Description

BASIC Auth. St. No. 67548 describes a device for measuring magnetic and electrical quantities, which is a bridge, created solely from Magnetic circuits, on one diagonal that has a winding applied, creating a magnetic flux in the system. In this structure, a mobile electrical measuring device is used as an indicator, located in the gap of the magnetic circuit, which is the second diagonal of the magnetic bridge.

By using this device, magnetic permeability, residual magnetization and coercive force can be determined. It is also possible to determine the magnetic properties at different magnetisation values (the magnitude of the flux magnetizing the core changes).

This device has the disadvantage that it has a low sensitivity, as a result of which its use is limited to substances with strong magnetic properties. The desire to increase the sensitivity leads to a significant increase and increase in the desire of the magnetic system.

In order to increase the sensitivity, in the proposed device, a diagonal of a magnetic bridge is applied to a saturation choke. A measuring device is included in the power supply circuit, graduated in units of magnitude measured by the magnetic bridge.

FIG. Figures 1, 2 and 3 show three possible diagrams of a device for determining the magnetic properties of various materials.

The device of FIG. 1 consists of a permanent magnet / (or electromagnet) with 1-POLE tips 2 between which there are two magnetic conductors 3 forming the shoulders of a magnetic bridge. Between the magnetic cores 3 is the core 4 of permallo

No. 84572-2 (or similar material) with windings. The core forms the diagonal of the magnetic bridge and is driven by a magnetic system of saturation throttles.

A substance having constant magnetic properties is introduced into two gaps 5 of the magnetic circuit. The test substance is introduced into the opposite gaps 6.

In the absence of the test substance in the gaps, their resistance is chosen so that through the diagonal (core) some initial magnetic bias flow can be seen. Its value should ensure the operation of saturation droplets on the steepest part of the characteristic.

With the introduction of the test substance into the gaps, the flow rate will change and cause a change in inductance of 7 drossel; current in the circuit, change what will be marked by the device.

To increase the sensitivity, it is advisable to feed the choke with an increased frequency current.

In order to reduce the dependence of the readings of the device on external magnetic fields and to increase the sensitivity, measuring circuits with a double magnetic bridge can be used.

In the diagram in FIG. The 2 windings of the saturation throttles are connected, like shoulders, to an electrical bridge for measuring inductance fed from an AC source. The initial magnetization of chokes is made so that when passing a test substance through gaps in one choke, the magnetization decreases, while in the other it increases. As a result, the inductance of one throttle will increase, and the other will decrease. The balancing of the bridge is broken, and device 7 will give a deflection. The advantage of this scheme is the constructive ease of arranging the chokes in such a way that a uniform external magnetic field leads to an unambiguous change in the magnitude of the initial biasing in both throttle systems, i.e. not reflected on the readings of the device 7. Similarly, the aging of the magnet within certain limits, does not affect the accuracy of the readings.

In the diagram in FIG. The 3 windings of the chokes, together with the capacitors 8 and 9, are the circuits of the two lamp generators 10 and 11.

Frequencies (I and / 2 generators) are inversely proportional to inductors of chokes and are fed to transformer 12, and the frequency of the beats after detection and amplification is measured by an arrow frequency meter 13. This frequency is proportional to the magnetic properties of the investigated substances. With an increase in. The magnitude of the initial frequencies fi and / 2 and reducing their difference, you can get a very high sensitivity of the device.

Subject invention

Claims (3)

1. A device for determining the magnetic properties of various materials according to the author. St. No. 67548, characterized in that, in order to increase its sensitivity, a saturation throttle forming a diagonal of a bridge is applied as a measuring system, the measuring circuit of which includes a measuring instrument graduated in units of a magnetically bled magnetic magnet. 2. The form of the device according to claim 1, characterized by the use of a double magnetic bridge, the chokes of which are included in the shoulders of an electric measuring bridge. 3. The form of the device according to claim 1, characterized by the use of a double magnetic bridge, the chokes of which are included as inductances in the oscillating circuits of two high-frequency generators, in order to make measurements using the beating method. t Ы, Ч, Н t-rY-H:. if / f -rr, 1 h. 7 7 6 g # il2.2