PL106221B1 - SYSTEM FOR THE MEASUREMENT OF MAGNETIC COERTION, ESPECIALLY IN MAGNETIC ELEMENTS OF TELETECHNICAL RELAYS - Google Patents

Description

The subject of the invention is a system for measuring magnetic coercivity, especially in magnetic elements of teletechnical transmitters.

In the hitherto known system for measuring magnetic coercivity, the tested element is introduced into a homogeneous magnetic field of a horizontally placed coil through which direct current flows and magnetizes element until magnetic saturation is achieved. Then the field of the coil is brought to zero and reversed the direction of the current slowly increases the field until the magnetization of the tested element disappears. Intensity the coercivity can then be calculated on the basis of the knowledge of the coil constant and the magnetizing current, or also read directly on the marked ammeter. The essence of the method is to determine the value of the field strength opposite, where the magnetization of the tested element disappears. Accuracy with which this can be determine depends on the sensitivity of the probe to measure the field. The most widely known solution is the converter transducer operating on the principle of even harmonics, the so-called Forster probe. The probe is placed outside the coil perpendicular to its field. System inconvenience when measuring soft magnetic materials it is necessary to compensate for the Earth's magnetic field. Some disturbances are introduced by close presence metal objects, as well as changing their position during the measurement. It also turned out to be local inclusions of other materials or local deformation of the structure can significantly alter the measurement the mean for the entire sample of the coercive intensity. This system has been used in precision units laboratory measurements.

In another arrangement, the fact that the intensity of the residual field magnetized to the state is used saturation of ferromagnetic elements is linearly dependent on the coercive intensity. Factor the numerical link of these quantities depends on the geometry of the tested element and on the distance between the element a measuring probe. The measuring probe is a hall effect transducer, or more commonly a transducer you. In this system, in order to make the measurement result independent of the differences in the distances of the examined person2 106 221 element from the measuring probe and to compensate for the influence of the Earth's field, an astatic system of four is used probes. At the time of measurement, the test piece is moved with a constant speed between the probe pairs. This arrangement it is characterized by a higher speed of testing elements and it is used in production measurements.

The aim of the invention is to develop a new system for measuring magnetic coercivity in small elements made of soft magnetic materials, especially in magnetic core elements of transmitters telecommunication.

The essence of the invention consists in measuring the residual field of magnetized elements a stationary system of two identical, push-in-place closed inductors was used those in the magnetic screen through which, at the time of the measurement, the tested elements fly free-flowing a constant height in the supporting pipe to which the release system is attached at the top. Such the solution is characterized by great simplicity, therefore - high reliability and ensures the measurement of the average for of the entire coercive intensity element.

The subject of the invention is illustrated in an exemplary embodiment in the drawing, which shows a system for lateral coercivity measurement.

The upper part of the release system 2 is attached to the downpipe 1, to which it is suspended the tested element 3, in the lower part of the downpipe 1, a system of measuring coils 4 is mounted in a double magnetic shield 5, the voltage pulse from the system of measuring coils 4 being it is fed to the input of the electronic measuring system 6. The measuring coils are fixed in the lower part a downpipe in which the magnetized, tested elements fall freely during the measurement. Pipe diameter it is selected in such a way that the falling elements do not hit the wall. The size is induced in the coils the resultant voltage impulse depends on the geometry of the tested element, its residual field and speed when passing through the measuring coils. Housing the measuring coil system with a double screen magnetic field eliminates the influence of variable external fields. In order to provide the elements and the same geometry, the same speed of passage through the measuring coils, they are always run from the same height, with a release device mounted on the top of the downpipe. Maximum value of the pulse voltage obtained from the system of measuring coils is directly proportional to the coercivity intensity.

The method of measurement according to the invention is distinguished by the ease of automating the entire measurement cycle and can be used in large-scale production measurements, for example for the selection of magnetic core elements teletechnical devices due to the value of the coercive intensity. f I klbd 120 + 18

Claims (1)

1. Patent claim. A system for measuring magnetic correction, especially in magnetic core elements of teletechnical transmitters, characterized in that for measuring the residual field of magnetized elements a stationary system of two identical push-pull induction coils (4), closed in the magnetic screen (5) by which, at the time of measurement, the tested elements (3) fly freely falling from a constant height in the resistance pipe (1) to which the release system (2) is attached in the upper part. «M« about Praol READING ROOM Poligraf. UP PRL NAL Urzedu eemft & A ^ o I * -> *