SU868540A1

SU868540A1 - Eddy-current testing device

Info

Publication number: SU868540A1
Application number: SU802870756A
Authority: SU
Inventors: Владимир Ишиевич Франкфурт
Priority date: 1980-01-11
Filing date: 1980-01-11
Publication date: 1981-09-30

Description

Изобретение относится к неразрушающему контролю и может быть использовано для вихретокового контроля электропроводящих ферромагнитных объектов.The invention relates to non-destructive testing and can be used for eddy current testing of electrically conductive ferromagnetic objects.

Известно устройство для вихретокового контроля, содержащее возбуждающую катушку индуктивности и две пары дифференциально включенных измерительных катушек индуктивности разных диаметров, соединенных с двумя соответствующими фазовыми детекторами, подключенными своими выхбдами к детектору отношения сигналов £|A device for eddy current control is known, which contains an exciting inductor and two pairs of differentially connected measuring inductors of different diameters, connected to two corresponding phase detectors, connected by their outputs to the signal ratio detector £ |

Однако такое устройство обладает недостаточной чувствительностью к магнитной проницаемости коротких объектов, что связано с уменьшением магнитного потока, взаимодействующего с контролируемым объектом и измерительными катушками при увеличении размагничивающего фактора.However, such a device has insufficient sensitivity to magnetic permeability of short objects, which is associated with a decrease in magnetic flux interacting with the controlled object and measuring coils with an increase in the demagnetizing factor.

Наиболее близким к предлагаемому является устройство для вихретокового ² контроля, содержащее соосно установленные возбуждающую и’две измерительные катушки разных диаметров, размещенные в параллельных друг другу плоскостях, и детектор отношения сигналов, соединенный одним из своих входов с измерительной катушкой меньшего диаметра [2].Closest to the proposed device is an eddy current ² control, containing coaxially mounted exciting and two measuring coils of different diameters, placed in parallel planes, and a signal ratio detector connected to one of its inputs with a measuring coil of a smaller diameter [2].

Однако и это устройство не обладает необходимой чувствительностью к магнитной проницаемости коротких объектов, что также связано с уменьшением потокосцепления между измерительными катушками и контролируемым объектом при увеличении его размагничивающего фактора.However, this device does not have the necessary sensitivity to the magnetic permeability of short objects, which is also associated with a decrease in flux linkage between the measuring coils and the controlled object with an increase in its demagnetizing factor.

Цель изобретения - повышение чувствительности к магнитной проницаемости коротких объектов.The purpose of the invention is to increase the sensitivity to magnetic permeability of short objects.

Поставленная цель достигается тем, что измерительные катушки размещены коаксиально и выполнены с одинаковым числом витков, а измерительная катушка большего диаметра подключена ко второму входу детектора отношения сигналов через измерительную катушку меньшего диаметра, соединенную с последней дифференциально.This goal is achieved in that the measuring coils are placed coaxially and are made with the same number of turns, and the measuring coil of a larger diameter is connected to the second input of the signal ratio detector through a measuring coil of a smaller diameter, connected to the latter differentially.

На чертеже представлена структурная схема предлагаемого устройства.The drawing shows a structural diagram of the proposed device.

Устройство для вихретоковогоEddy current device

Использование предлагаемого устройства обеспечивает необходимую чувствительность к магнитной проницаемости коротких изделий и может 5 эффективно использоваться для их структороскопии..Using the proposed device provides the necessary sensitivity to magnetic permeability of short products and can 5 be effectively used for their structuraloscopy ..

контроля состоит из соосно установленных возбуждающей катушки Ц измерительной катушки 2 большего диаметра _;; (и измерительной катушки 3 меньшего диаметра, детектора 4 измерения отношения сигналов, соединенного своим первьач входом с измерительной катуркой 3 меньшего диаметра, а вторым входом подключе г к измерительной катушке 2 большего дна метра через измерительную катушку 3 меньшего диаметра, соединенных между собой дифференциально.control consists of coaxially mounted exciting coil Ts measuring coil 2 of a larger diameter _;; (and a measuring coil 3 of smaller diameter, a detector 4 measuring the signal ratio, connected by its first input to a measuring coil 3 of a smaller diameter, and by a second input connecting to a measuring coil 2 of a larger bottom meter through a measuring coil 3 of a smaller diameter, which are connected differentially.

Устройство работает следующим образом. ²⁰ The device operates as follows. ²⁰

В результате взаимодействия измерительных катушек 2 и 3 с изделием 5 в поле возбуждающей катушки 1 сигналы катушек пропорциональны проходящему через них магнитному потоку. ²⁵ As a result of the interaction of the measuring coils 2 and 3 with the product 5 in the field of the exciting coil 1, the signals of the coils are proportional to the magnetic flux passing through them. ²⁵

Поэтому сигнал на втором входе детектора 4 отношения сигналов пропорционален разностному потоку измеритель^·! ных Катушев 2 и 3, а следовательно, и напряженности мапнитного поля Н в ³⁰изделии 5·. В то же время сигнал на первом входе детектора 4 пропорционален магнитной индукции В в изделииTherefore, the signal at the second input of the detector 4 of the signal ratio is proportional to the difference flow meter ^ ·! ny Katushev 2 and 3, and consequently, the strength of the field of the magnetic field H in ³⁰ product 5 ·. At the same time, the signal at the first input of the detector 4 is proportional to the magnetic induction B in the product

5. Поэтому выходной.сигнал пропорционален отношению В к Н. Это обеспечи- 3S вает значительное повышение чувствительности к магнитной проницаемости изделия 5 с размагничивающим фактором, отличным от нуля.5. Therefore, the output signal is proportional to the ratio of B to N. This provides a 3S significant increase in the sensitivity to magnetic permeability of the product 5 with a demagnetizing factor other than zero.

Claims

(54) DEVICE FOR VORTEX CONTROL OF THE INVENTION The invention relates to non-destructive testing and can be used for eddy current testing of electrically conductive ferromagnetic objects. A device dp shhretokogov kontrol is known that contains a carcass of inductance and two pairs of differentially connected measuring inductors of different diameters connected to two corresponding phase detectors connected by their outputs to a signal ratio detector | However, such a device has an inadequate sensitivity to the permeability of short objects, which is associated with a decrease in the magnetic flux, interacting with the object being monitored and the measuring coils with increasing demagnetizing factor. Closest to the present invention, there is a device for eddy current testing, containing coaxially mounted excitation and two measuring coils of different diameters, placed in planes parallel to each other, and a signal ratio detector, connected by one of its inputs to a measuring coil of smaller diameter f2. However, this device does not have the necessary sensitivity to the magnetic permeability of short objects, which is also associated with a decrease in the flux linkage between the measuring coils and the object being monitored with an increase in its demagnetizing factor. The purpose of the invention is to increase the sensitivity to magnetic permeability of short objects. The goal is achieved by the fact that the measuring coils are placed coaxially and are made with the same number of turns, and the measuring coil of a larger diameter is connected to the 3 second input of the signal ratio detector via a measuring coil of smaller diameter connected to the last differential. The drawing shows a block diagram of the proposed device. The device for eddy current testing consists of coaxially mounted excitation coil 1 of measuring coil 2 of larger diameter and measuring coil of 3 smaller diameter, measuring detector 4 related to signals connected with its primary input of measuring 3 of smaller diameter, and the second key input to to the measuring coil 2 of the larger bottom of the meter through the measuring coil 3 of a smaller diameter, connected by a melada differential. The device works as follows. As a result of the interaction of the measuring coils 2 and 3 with the product 5 in the field of the exciting coil, the signals of the coils are proportional to the magnetic flux passing through them. Therefore, the signal at the second input of the detector 4 of the signal ratio is proportional to the difference flow of measuring Katushev 2 and 3, and, consequently, the intensity of the magnetic field H in product 5-. At the same time, the signal at the first input of detector 4 is proportional to the magnetic induction B in product 5. Therefore, the output signal is proportional to the ratio B to N. This provides a significant increase in sensitivity to the magnetic permeability of product 5 with a demagnetizing factor that differs from zero. The use of the proposed device provides the necessary sensitivity to the magnetic permeability of short products and can be effectively used for their structroscope. Claim of the Invention A device for eddy current testing comprising coaxially mounted exciting and two measuring coils of different diameters placed in planes parallel to each other and a signal ratio detector connected to one of its inputs with a measuring coil of a smaller diameter, characterized in that, in order to increase sensitivity to magnetic permeability of short objects the measuring coil are arranged coaxially and are made with the same number of turns, and the measuring coil of larger diameter connected to the second; the input of the detector is a relative signal (through a measuring coil of smaller diameter, connected to the latter differentially. Sources of information taken into account during the examination 1. Author's certificate of the USSR No. 563555, class G 01 B 7/06, 1977.

2. The author's certificate of the USSR 487342, cl. G 01 N 27/86 1975 (prototype).

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