SU587424A1

SU587424A1 - Method of measuring the coercitive force of ferromagnetic articles

Info

Publication number: SU587424A1
Application number: SU762391968A
Authority: SU
Inventors: Николай Николаевич Зацепин; Николай Онуфриевич Гусак; Алексей Всеволодович Чернышев
Original assignee: Отдел Физики Неразрушающего Контроля Ан Белорусской Сср
Priority date: 1976-08-09
Filing date: 1976-08-09
Publication date: 1978-01-05

Description

Изобретение относитс к магнитным измерени м , и может быть использовано дл контрол качества ферромагнитных изделий по коэрцитивной силе.The invention relates to magnetic measurements, and can be used to control the quality of ferromagnetic products by coercive force.

Известен способ измерени коэрцитивной 5 силы, заключающийс в том, что изделие перемагничивают переменным магнитным полем по предельной петле гистерезиса, регистрируют величину сигнала, пропорциональную изменению намад ниченности материала, пе- ю ремешают переменное магнитное поле в стО poiry положительного или отрицательного намагничивани при помощи посто нного магнитного пол до уменьшени наполовину зарегистрированного сигнала, и коэрцитивную 15 силу определ ют по разнице намагничиваюших палей ij «A known method for measuring the coercive force 5 is that the product is re-magnetized by an alternating magnetic field along the limiting hysteresis loop, a signal is recorded that is proportional to the change in the material opalescence, and the alternating magnetic field is stirred by a positive or negative magnetization using constant the magnetic field to reduce the half-registered signal, and the coercive force 15 is determined by the difference of the magnetized fingers ij "

Этот способ замелл ет контроль.This method locks the control.

Наиболее близок к предлагаемому способ 20 измерени коэрцитивной силы ферромагнитных изделий с помощью накладного- электромагнит ного перобразовател , заключающийс в намагничивании изделий переменным магнитным 1олем, одновременном подмахничиваыии посто нным полем, выделении четных гармоник измеренного сигнала 2J ,Closest to the proposed method 20 is the measurement of the coercive force of ferromagnetic products using an overhead electromagnetic transducer, which consists in magnetizing products with a variable magnetic field, simultaneously under the constant field, extracting even harmonics of the measured signal 2J,

Этот способ обладает недостаточной чувс-рвительностью и разрешающей способностью к изменению коэрцитивной силы.This method has insufficient sensitivity and resolution to change the coercive force.

Цель изобретени - повышение чувствительности и разрешающей способности измерений - достигаетс тем, что при измерении коэрцитивной силы способом, заключающимс в намагничивании изделий переменным магнитным полем, одновременном подмагничи- вании посто нным полем и выделении четных гармоник измеренного сигнала компенсирующее магнитное поле, выделенную вторую гармонику компенсируют до нул , изменение KONпенсирующего магнитного пол преобразуют в электрический сигнал, по величине которого в момент компенсации второй гармоники суд т о коэрцитивной силе.The purpose of the invention is to increase the sensitivity and resolution of measurements - by measuring coercive force in a way consisting in magnetizing products with an alternating magnetic field, simultaneously magnetising a constant field and separating the even harmonics of the measured signal, compensating the magnetic field allocated to the second harmonic to compensate for zero, the change of the condensing magnetic field is converted into an electrical signal, the magnitude of which at the time of compensation of the second harmonic court r about coercive force.

На чертеже приведена схема устройства дл измерени коэрцитивной силы ферромш нитных изделий предлагаемым способом.The drawing shows a diagram of a device for measuring the coercive force of ferrous products by the proposed method.

Claims

The alternating field drive coil 1 is connected to generator 2, measuring 3 and compensating 4 coils are connected to each other and connected to a selective amplifier of the second harmonic 5, the output of which is connected to indicator 6. In addition, the device contains a permanent magnet 7 , compensator 8 from the material of the tested product, installed with the possibility of mixing along the coil axes; transducer 9 of the linear displacement of the compensator in into the electrical signal and signal meter 10. O s is in a container one of the plates is fixedly attached and the other compensator 8, to measure forces koertsitavnoy ferromagnetic articles converter 9 ™ mouth time here to a controlled product. By magnetizing the product by alternating magnetic noi of llamas caused by the excitation current flowing through the excitation coil 1, as well as by a constant-magnet submagnet, magnet 7 | The compensator 8 is placed on a paccToa tion, in which it does not affect the compensation coil 4. As a result, the VIA induces a variable and permanent magnetic field product in the measuring coil 3 to induce a complex signal containing both even and odd harmonic components, In the compensation coil, only the first harmonics are induced. As the measuring 3 and the compensation 4 coils are differentially connected, the selective amplifier 5 selects the second harmonic, which is fixed by the indicator 6, then Mesh Compensator 8 towards the coils. A variable and permanent magnetic field also begins to affect the compensator from the material of the controlled product, and an emf containing the second harmonic is induced in the compo- sition coil. The compensator is shifted until the second harmonic, induced by the compensation coil, is not equalized with the second harmonic of the measuring coil, and at the output of the converter the signal becomes zero. Linear mixing of the compensator 8 to the coils, characterizing the coercive force, is converted into an electrical signal by means of a capacitive transducer 9 and recorded by the meter 10, the coercive force is judged by the magnitude of this signal. The movement of the compensator is measured in the interval when the emf of the second harmonic from the maximum does not reach zero. The method has a high sensitivity and resolution to coercive force. With small changes in the coercive force, considerable mixing of the compensator is required. In addition, the method makes it possible to measure the coercive force of products of more complex shape with ease and with high productivity. Claims The method of measuring the coercive force of ferromagnetic products using superimposed electromagnetic transducers is included in the magnetizations of the product tjen by the belt magnetic field simultaneously magnetising the constant field, highlighting the even harmonics of the measured signal, characterized in that in order to increase the sensitivity and resolving; capabilities, inputting a compensating magnetic field, allocated to the second intercivtoHHKy, compensating to zero, changing the compensating magnetic file into an aerial signal, judging by the magnitude of the signal in the second harmonic compensation Momentum; OTHER FORCE: Sources of information taken into account during the examination: 1 USSR author's certificate No. 428320, G-O1 R 33/12, 1974,

2. USSR author's certificate No. 386354, G 01 R 33/12, 1973,

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