Apparatus for measurement of strong magnetic fields

Description:

The invention relates to the measurement technique, in particular to devices for measuring magnetic quantities.

It is already known the magnetoresistor, which represents a transducer that can be used in devices for measuring the magnetic field and which includes a magnetoresistive element, made of a magnetic film [1].

It is also known the sensitive element used in the process of measuring the magnetic field, where as a sensitive element is used a conductive wire, powered by alternating current [2]. The value of the magnetic field is determined by the size of the conductor's own inductance, which appears in the magnetic field or by the value of its electrical resistance.

The closest to the proposed element is the sensitive element of the device for measuring the low magnetic fields [3]. The sensing element is made of a strip of ferromagnetic material, which is wrapped on a cylindrical spiral-shaped housing. The construction is completed with output terminals, made of aluminum alloy. The use of such a sensitive element provides the device with high thermal stability in the process of measuring the magnetic field.

The common disadvantage of these sensors is their ability to record only low magnetic fields (up to 5T), ie a small working range.

The problem that the invention solves is the widening of the field of magnetic field registration.

The essence of the invention is that the device for measuring the powerful magnetic fields includes a sensitive element, located on a textolite support and executed in the form of metallic wire from bismuth in glass insulation. The ends of the wire are fixed to the copper strips, deposited on the opposite edges of the support. Two electrical contacts are welded on the copper strips.

The invention is explained by figures.

The device, according to the invention, consists of a metallic wire from Bi (1) in glass insulation with a diameter of 1.5 ... 3.0 pm and a length of 4 mm, the electrical resistance of which changes at its location in the magnetic field, fastened to a support made of textolite (2), at the two ends of which four electrical contacts are welded on the copper strips: two (3) and (4) for supplying the electric current element (0.1 ... 10.0 pA) and other two (5) and (6) - for recording the potential difference from the sensitive element or the resistance, which changes at the variation of the magnetic field.

The device works as follows. When the DC current passes through the Bi wire (through the contacts (3) and (4), the initial resistance of the element (from the contacts (5) and (6)) is recorded in the absence of the magnetic field. it changes according to the variation of the magnetic field.

The calibration curve of the sensitive element is expressed by the dependence of the resistance on the magnetic field R = f (H) and is obtained by changing the magnetic field in two directions (increasing and decreasing). The calibration curve is valid for a set of elements, made of wires of the same size (diameter and length).

The advantages of using such a sensitive element are:

- quasi-linear dependence of the resistance of the magnetic field in a wide range of values ​​of the magnetic field: from 0 to 32 T;

- the small dimensions of the sensitive element (4.0 x 2.0 mm), which can be adjusted in microsensors with different destinations;

- high initial resistance of the element (of order 10²... 10⁴ Ω) provides о high value of the output signal, which does not require amplification and simplification of the electrical circuit.

MD 2270 C2 2003.09.30