SU608111A1 - Permeameter - Google Patents

Description

(54) PERMEAMETER

one

The invention relates to the field of electrical measuring equipment and can be used to measure the magnetic characteristics of ferromagnetic materials.

Permeameters are known for determining the characteristics of ferromagnetic materials, containing a magnetic conductor, coils for magnetizing and demagnetizing the sample, and measuring the field strength and induction {).

The disadvantage of these permeameters is low accuracy at high frequencies.

The closest to the proposed device to the technical essence is a permeameter containing a ferromagnetic core with a primary winding wound on it, and a secondary coil made in the form of a coaxial cylinder with a lid. The cavity of the coaxial cylinder serves as a container into which the measured sample is placed (2).

However, when using such a permeameter, it is not possible to measure the insertion resistances at a frequency of 1 MHz that are smaller than 6-10 ohms by the active component and ohms by the reactive component.

To increase sensitivity in a permeameter containing a ferromagnetic core; primary winding wound on it, and

2

A secondary coil, made in the form of a coaxial cylinder with a lid, introduces a choke with variable inductance and a variable resistor, and the outer and inner electrodes of the cylinder are connected to each other through serially connected primary windings, a choke with a variable inductance and a variable resistor.

FIG. i shows the proposed permeameter; in fig. 2 - his electrical circuit.

The permeameter consists of a ferromagnetic core I. on which winding 2 is located. A core with a winding is mounted on the central electrode 3 of a coaxial cable, the outer electrode 4 of which is made in the form of a hollow cylinder. The coaxial cable is shorted from above by a flap 5, and from below the electrodes 3 and 4 are connected via a variable resistor 6, a choke 7 with a variable inductance and a winding 8, and a coiled core. The permeameter is covered by a common housing 9. The coaxial cable shown in FIG. 2, is made in the form of a winding 10.

The described construction and the elements included in it are a diagram of an asymmetrical transformer bridge (see Fig. 2), in which the elements of the comparison are a variable transistor 6 and a choke 7 with variable inductance.

The device works as follows. Determination of the magical characteristics of ferromagnetic materials with the help of the proposed device is carried out by connecting the scientific research institute to the terminals P and the balance indicator (voltmeter) to terminals 12. The circuit is twice in a state of balance (without a measured sample and sample, which is placed in the cylinder cavity serving as the measuring container). After each balance of the circuit, a chain consisting of a variable resistor 6 and variable inductance throttles 7 is disconnected from the circuit and connected to an impedance meter (cumeter), which is used to divide the complex resistance of the chain into active and reactive parts. The measured value is determined by the calculated formulas for the permeameters taking into account the transfer coefficient of the bridge circuit.

The proposed permeameter is distinguished by the fact that its bridge circuit increases by 1-2 per ./

The sensitivity of the permeameter is compared with known constructions.

Claims (1)

1. Fevraleva V.E. Magneto-solid materials and permanent magnets. “Naukova Duma, Kiev, 1969, p. 132-134. 2 USSR Author's Certificate No. 168376, cl. G 01 R 38/12, 1965. BUT" /