SU815690A1

SU815690A1 - Magnetic field intensity measuring device

Info

Publication number: SU815690A1
Application number: SU792761018A
Authority: SU
Inventors: Николай Иванович Горбатенко; Николай Борисович Тушканов
Original assignee: Новочеркасский Ордена Трудовогокрасного Знамени Политехническийинститут Им. Серго Орджоникидзе
Priority date: 1979-05-03
Filing date: 1979-05-03
Publication date: 1981-03-23

Description

Изобретение относится к магнитным измерениям и предназначено для измерения напряженности магнитного поля.The invention relates to magnetic measurements and is intended to measure magnetic field strength.

Известен следящий магнитометр, содержащий генератор, датчик ядерного магнитного резонанса, усилитель, управитель частоты, преобразователь код-напряжение, приемник сигнала сшибки, дискриминатор уровней, реверсивный счетчик, регистрирующее устройство (11.A known magnetometer comprising a generator, a nuclear magnetic resonance sensor, an amplifier, a frequency controller, a code-voltage converter, an error signal receiver, a level discriminator, a reversible counter, a recording device (11.

Однако вследствие больших размеров датчика ядерного магнитного резонанса, устройство не позволяет измерять магнитные поля в малых объе- '5 мах и на малом расстоянии от поверхности ферромагнитных тел, т.е, данное устройство не используется для испытания образцов из ферромагнитных материалов. 20However, due to the large size of the nuclear magnetic resonance sensor, the device does not allow measuring magnetic fields in small volumes of '5 max and at a small distance from the surface of ferromagnetic bodies, i.e., this device is not used to test samples of ferromagnetic materials. 20

Известно также устройство, содержащее феррозонд, в цепь намагничивающей обмотки которого включен генератор прямоугольных импульсов и последовательно соединенные переменный и эталонный резисторы, параллельно которым включен измерительный прибор, а в цепь выходной обмотки феррозонда включены последовательно соединенные усилитель, интегратор, 30 пороговый блок и индикаторный прибор. Устройство позволяет измерять большие поля у поверхности ферромагнитных тел компенсационным методом (2].A device containing a flux-gate is also known, in the magnetizing winding of which there is a square-wave generator and series-connected alternating and reference resistors, in parallel with which a measuring device is connected, and a series-connected amplifier, integrator, 30 threshold unit and indicator device are included in the output winding of the flux-gate. The device allows you to measure large fields near the surface of ferromagnetic bodies by the compensation method (2].

Недостатками устройства являются большое время процесса измерения и невозможность измерения изменяющихся во времени магнитных полей, обусловленные ручной регулировкой амплитуды компенсирующего поля. Эти недостатки затрудняют использование устройства в автоматических установках для испытания магнитных материалов.The disadvantages of the device are the long time of the measurement process and the inability to measure time-varying magnetic fields, due to manual adjustment of the amplitude of the compensating field. These disadvantages make it difficult to use the device in automatic installations for testing magnetic materials.

Цель изобретения - повышение быстродействия устройства.The purpose of the invention is to increase the speed of the device.

Поставленная цель достигается тем, что устройство для измерения напряженности магнитного поля, содержащее генератор прямоугольных импульсов, феррозонд, к выходной обмотке которого подключен интегратор, выходом соединенный со входом усилителя, выход которого соединен со входом порогового блока, и измерительный прибор, снабжено последовательно соединенными элементом И-НЕ, реверсивным счетчиком импульсов, цифроаналоговым преобразователем, управ ляе№1м источником тока и ключом, причем второй вход реверсивного счетчика импульсов и первый вход логического элемента И-НЕ соединены с выходом порогового блока, второй вход логического элемента И-НЕ соединен с выходом генератора прямоугольных импульсов, выход цифро-аналогового преобразователя И-НЕ соединен со входом измерительного прибора» Второй вход ключа подключен к выходу генератора прямоугольных импульсов, а выход ключа соединен с намагничивающей обмоткой феррозонда.This goal is achieved by the fact that the device for measuring the magnetic field strength containing a rectangular pulse generator, a flux gate, to the output winding of which an integrator is connected, with an output connected to the input of the amplifier, the output of which is connected to the input of the threshold unit, and the measuring device is equipped with series-connected element And -NOT, a reversible pulse counter, a digital-to-analog converter, controlling the # 1m current source and key, with the second input of a reverse pulse counter and first the input of the AND gate is connected to the output of the threshold block, the second input of the gate AND is connected to the output of the rectangular pulse generator, the output of the digital-to-analog converter is NOT connected to the input of the measuring device ”The second key input is connected to the output of the square wave generator and the key output is connected to the magnetizing winding of the flux gate.

На фиг. 1 изображена структурная схема устройства для измерения напряженности магнитного поля; на фиг. 2 и фиг. 3 - временные диаграммы работы устройства.In FIG. 1 shows a block diagram of a device for measuring magnetic field strength; in FIG. 2 and FIG. 3 - time diagrams of the operation of the device.

Устройство для измерения напряжен ности магнитного поля содержит управляемый источник 1 тока, выход которо- 20 го соединен с потенциальным входом . ключа 2, управляющий вход которого соединен с выходом генератора прямоугольных импульсов 3, а выход его соединен с намагничивающей обмоткойферрозонда 4, к выходной обмотке которого подключен интегратор 5, соединенный со входом усилителя 6, выход которого соединен со входом порогового блока 7, выход которого подключен к одному из входов реверсивного счетчика импульсов 8 и к одному из входов логического элемента И-НЕ 9, другой еход которого соединен с выходом генератора 3 прямоугольных импульсов, а выход - с другим входом .A device for measuring the magnetic field strength contains a controllable current source 1, the output of which 20 is connected to a potential input. key 2, the control input of which is connected to the output of the rectangular pulse generator 3, and its output is connected to the magnetizing coil of the probe 4, to the output winding of which is connected an integrator 5, connected to the input of the amplifier 6, the output of which is connected to the input of the threshold unit 7, the output of which is connected to one of the inputs of the reversible pulse counter 8 and to one of the inputs of the AND-NOT 9 logic element, the other path of which is connected to the output of the generator 3 of rectangular pulses, and the output to the other input.

реверсивного счетчика 8 импульсов, выход которого соединен со входом цифроаналогового преобразователя 10, выход которого соединен со входом измерительного прибора 11 и со входом 40 управляемого источника 1 тока.a reverse counter 8 pulses, the output of which is connected to the input of the digital-to-analog converter 10, the output of which is connected to the input of the measuring device 11 and to the input 40 of the controlled current source 1.

Устройство работает следующим образом.The device operates as follows.

Феррозонд 4 помещают в постоянное или изменяющееся во времени измерявмое поле Н_изм (фиг. 2). Состояние сердечника феррозонда определяется величиной поля Н_иу_м и величиной компенсирующего импульсного поля Н_к,создаваемого током намагничивающей обмотки феррозонда 4, Частота следования прямо угольных импульсов компенсирующего поля равна частоте импульсов генератора 3 прямоугольных импульсов, а амплитуда пропорциональна току управляемого источника 1 тока, коммутируе- 55 мого ключом 2. Для нормальной работы устройства измеряемое и компенсирующее поля направлены встречно. Импульсы напряжения, индуцируемые в выходной обмотке феррозонда 4 в процессе ¢0 перемагничивания его сердечника (U uix на фиг. 2), интегрируются интегратором 5, напряжение на выходе интегратора (Ms на фиг. 2) пропорционально изменениям индукции в сердечнике фер- ^5 роэонда 4. Усиленные усилителем 6 импульсы подаются на вход порогового блока 7, настроенного таким образом, что импульсы на его выходе появляются, если изменения индукции в сердечнике феррозонда 4 превышают величину, равную максимальной индукции петли гистерезиса материала сердечника ( и₇на фиг. 2). Сердечник феррозонда выполнен из пермаллоя с петлей гистерезиса с коэффициентом прямоугольности, близким к единице, т.е. величина максимальной индукции материала сердечника практически не зависит от напряженности магнитного поля и равна величине остаточной индукции В_г(фиг. 2). Таким образом, если измеряемое поле Н_изм меньше аютлитуды компенсирующего поля Н_Кт на выходе порогового блока 7 появляется импульс (моменты ц, t₃, t₅, t₆, tg, t?, > ^13’ *451 ^17> t^g _r tg-χ НЙ фИГ. 3 воздействующий на вход вычитание реверсивного счетчика 8. импульсов и на один из входов логического элемента И-НЕ 9, запрещая воздействие импульса с генератора 3 прямоугольных импульсов через логический элемент И-НЕ 9 на вход суммирование реверсивного. счетчика 8 импульсов. В результате уменьшается число, записанное в реверсивном счетчике импульсов 8, напряжение на выходе цифроаналогового преобразователя 10 и ток управляемого источника 1. Если измеряемое поле Н _llJM. больше амплитуды компенсирующего Н _к на выходе порогового блока 7, импульс не появляется (моменты t _г , , t₇ , t₁₀, t_M, t₍₆, t₂o> tzv на фиг. 3). Импульс с генератора 3 прямоугольных импульсов воздействует через логический элемент И-НЕ 9 на вход суммирование реверсивного счетчика 8 импульсов, вследствие чего увеличивается число,.записанное в нем, а также напряжение на выходе цифроаналогового преобразователя 10 и ток L управляемого источника'1 тока.Flux gate 4 is placed in a constant or time-varying field H izmeryavmoe _rev (Fig. 2). The state of the core of the fluxgate is determined by the magnitude of the field H _and _ym and the value of the compensating pulsed field H _k created by the magnetizing current of the fluxgate 4, The repetition rate of rectangular pulses of the compensating field is equal to the frequency of the pulses of the generator 3 of rectangular pulses, and the amplitude is proportional to the current of the controlled current source 1, commuting - 55 key 2. For normal operation of the device, the measured and compensating fields are directed in the opposite direction. The voltage pulses induced in the output winding of the fluxgate 4 in the process ¢ 0 of the magnetization reversal of its core (U uix in Fig. 2) are integrated by the integrator 5, the voltage at the output of the integrator (Ms in Fig. 2) is proportional to the changes in the induction in the core of the fer- ^ 5 rayon 4. The pulses amplified by the amplifier 6 are fed to the input of the threshold block 7, which is configured so that pulses appear at its output if the changes in the induction in the core of the flux-gate 4 exceed a value equal to the maximum induction of the hysteresis loop of the core material (and ₇ in Fig. 2). The core of the fluxgate is made of permalloy with a hysteresis loop with a rectangular coefficient close to unity, i.e. the value of the maximum induction of the core material is practically independent of the magnetic field strength and is equal to the value of the residual induction V _g (Fig. 2). Thus, if the measured field H is _edited less ayutlitudy compensating field H _Rm at the output of the threshold a pulse unit 7 (points p, t _3, t _5, t _6, tg, t ?,> ^ 13 '^ 17 * 451> t ^ g _r tg-χ NY FIG. 3 acting on the input subtraction of the reverse counter 8. pulses and on one of the inputs of the AND-NOT 9 logic element, prohibiting the effect of a pulse from the generator 3 of rectangular pulses through the AND-NOT 9 logic element on the input of the reversal summation. counter 8 pulses. As a result, decreases the number recorded in the reverse counter of pulses 8 voltage output digital to analog converter 10 and a current controlled source 1. If the measured field H _llJM. greater amplitude compensating H _to the output of the threshold unit 7, the pulse does not appear (times t _r,, t _7, t _10, t _M, t _(6, t ₂ o> tzv in Fig. 3). The pulse from the rectangular pulse generator 3 acts through the AND-NOT 9 logic element to the input, the summation of the reversible pulse counter 8, as a result of which the number recorded in it, as well as the voltage at the output of the digital-to-analog converter 10 and current L of the controlled current source'1.

Таким образом, амплитуда компенсирующего поля П_к автоматически следит за величиной напряженности измеряемого поля ,причем показания измерительного прибора ll-прямо пропорциональны величине напряженности' компенсирующего,а значит и измеряемого поля Н_изм»Устройство проградуировано в единицах напряженности магнитного поля.Thus, the amplitude of the compensating field P _k automatically monitors the magnitude of the measured field strength, and the readings of the measuring device are ll-directly proportional to the magnitude of the compensating, and therefore the measured field H _meas . The device is calibrated in units of the magnetic field strength.

Наличие в предлагаемом устройстве системы автоматического регулирования амплитуды импульсного компенсирующего поля полностью автоматизирует процесс измерения напряженности магнитного поля и позволяет измерять напряженность изменяющихся во времени магнитных полей.The presence in the proposed device of a system for automatically controlling the amplitude of a pulsed compensating field fully automates the process of measuring the magnetic field strength and allows you to measure the intensity of time-varying magnetic fields.

Устройство может быть использовано как в качестве отдельного измери5 теля напряженности магнитного поля/ так и в качестве элемента автоматических магнитоизмерительных систем.The device can be used both as a separate magnetic field strength meter / and as an element of automatic magnetic measuring systems.

Claims

The invention relates to magnetic measurements and is intended to measure the magnetic field strength. A magnetometer is known for holding a generator, a nuclear magnetic resonance sensor, an amplifier, a frequency controller, a code-voltage converter, a mistake signal receiver, a level discriminator, a reverse counter registered with the device 11. However, due to the large size of the nuclear magnetic resonance sensor, the device does not allow magnetic fields to be measured in small volumes and at small distances from the surface of ferromagnetic bodies, i.e. This device is not used to test specimens and: s ferromagnetic materials. It is also known a device containing a flux probe, in the magnetizing winding circuit of which a rectangular pulse generator is connected and series-connected alternating and reference resistors, in parallel with which a measuring device is connected, and a series-connected amplifier, integrator are included in the output winding circuit. threshold unit and indicator device. The device makes it possible to measure large fields near the surface of ferromagnetic bodies by the compensation method 12. The disadvantages of the device are the large time of the measurement process and the impossibility of measuring time-varying magnetic fields due to the manual adjustment of the amplitude of the compensating field. These drawbacks make it difficult to use the device in automatic installations for testing magnetic materials. The purpose of the invention is to increase the speed of the device. This goal is achieved by the fact that a device for measuring the intensity of a magnetic field, containing a square pulse generator, a ferrosonde probe, to the output winding of which an integrator is connected, an output connected to the input of an amplifier, an output of which is connected to the input of a threshold unit, and a measuring device, are equipped with each other connected the NAND element, a reversible pulse counter, a digital-to-analog converter, a current source control and a key, the second input of the reversible pulse counter and The first input of the logical element AND-NOT is connected to the output of the threshold unit, the second input of the logical element AND-NOT is connected to the output of the generator of rectangular pulses, the output of the digital-to-analog converter AND-NOT soy, is connected to the input of the measuring device The second input of the key is connected to the output of the generator pulses are connected to the magnetizing winding of the fluxgate. FIG. 1 shows a block diagram of a device for measuring the strength of a magnetic field; FIG. 2 and FIG. 3 - timing charts of the device. A device for measuring the intensity of a magnetic field contains a control: .1st current source 1, the output of which is connected to a potential input. key 2, the control input of which is connected to the output of the generator of rectangular pulses 3, and its output is connected to the magnetizing winding of the ferro probe 4, an integrator 5 connected to the output winding of KotojJoro, connected to the input of the amplifier 6, whose output is connected to the input of the threshold unit 7, the output of which is connected to one of the inputs of the reversible pulse counter 8 and to one of the inputs of the logical element AND-NOT 9, the other input of which is connected to the output of the generator 3 rectangular pulses, and the output to another input, a reversible counter In Single pulses you turn is connected to the input transducer 10 tsifrranalogoBOGo you turn is connected to the input of the measuring device 11 and to the input of the controllable current source 1. The device works as follows. Ferrosonde 4 is placed in a constant or time varying measured field H, Jm (Fig. 2). The state of the core of the ferrozones is determined by the field H and the magnitude of the compensating pulsed field Hj, which is determined by the current of the magnetizing winding of the ferrosonde 4, the frequency of the right angle pulses of the field of the field is equal to the frequency of the generator pulses of 3 right angle pulses, and the second field is equal to the frequency of the generator pulses of 3 right angle impulses, and the second field is equal to the frequency of the generator pulses 3 right angle impulses, and the second field is equal to the frequency of the generator pulses 3 right angle impulses, and the second field is equal to the frequency of the impulses of the generator 3 right angle impulses, and the second field is equal to the frequency of the impulses of the generator 3 right angle impulses, and one second field is equal to the frequency of the impulses of the generator 3 right angle impulses, and one second field equal to the frequency of the impulses of the generator 3 right angle impulses, and one second field equal to the frequency of the impulses of the generator 3 right angle impulses, and one second field equal to the frequency of the impulses of the generator 3 right angle impulses; source 1 of the current, commuting with key 2. For normal operation of the device, the measurable and compensating floor sent: counter. The voltage pulses induced in the output winding of the fluxgate 4 during the remagnetization of its core (U titi in FIG. 2) are integrated by integrator 5, the voltage at the output of the integrator (1 / S in Fig. 2) is proportional to the change in induction in the core headlights ozonde 4. Pulses amplified by amplifier b are fed to the input of threshold unit 7, which is configured so that pulses appear at its output if changes in induction in core 4 of the fluxgate 4 exceed the value of the maximum induction of the core material hysteresis loop Fig. 2). The core of the fluxgate is made of permallo with a hysteresis loop with a square coefficient close to unity, i.e. the magnitude of the maximum induction of the core material is practically independent of the magnetic field strength and is equal to the residual induction value B (Fig. 2). Thus, if the measured field Nssm is smaller than the aggliplitude of the compensating field Hst at the output of the threshold block 7, a pulse appears (moments t. Ta. 5: 2 13 Ch t ti9 Chg and fig 3) affecting the input subtraction of the reversible counter 8. pulses and one of the inputs of the logical element AND-NOT 9, prohibiting the impact of a pulse from the generator 3 rectangular pulses through the logical element AND-NOT 9 to the input of the summation of the reversing counter 8 pulses. As a result, the number recorded in the reversible pulse counter 8 decreases, the output voltage of the digital-to-analog converter 10 and the current of the controlled source 1 decrease. 1, tj, t, t, 4, tjo, tj, in Fig. 3). A pulse from a generator of 3 rectangular pulses acts through the logical element I-HE 9 on the input, the summation of the reversible counter of 8 pulses, resulting in an increase in the number recorded in it, as well as the output voltage of the D / A converter 10 and the current L of the controlled current source. Thus, the amplitude of the compensating field H automatically monitors the intensity of the measured field HKJM., And the meter readings are 11 directly proportional to the magnitude of the Generation :) compensated and therefore the measured field HUJMV The device is calibrated in units of the intensity of the magnetic field. The presence in the proposed device of a system for automatically controlling the amplitude of the pulse compensation field completely automates the process of measuring the intensity of the magnetic field and makes it possible to measure the intensity of the magnetic fields changing during the time. The device can be used both as a separate measuring device of the magnetic field strength and as an element of automatic magnetometerization systems. The invention The device for measuring the intensity of a magnetic field containing a square pulse generator, a ferro probe, to the output winding of which an integrator is connected, output connected to an amplifier input, the output of which is connected to the input of a threshold unit, and a measuring device that has that, in order to improve the speed of the device, it is equipped with a series AND NAND logic element, a reversible pulse counter, a digital analog converter controlled by the source then with a key, the second input of the reversible pulse counter and the first input of the I-HE logic element are connected to the output of the threshold block, the second input of the I-NOT logic element is connected to the output of the rectangular pulses, the output of the digital-to-analog 17 transformer is connected to the input of a smart device, the second input the key is connected to the generator output of rectangular pulses, and the key output is connected to the magnetizing winding of the fluxgate. Sources of information taken into account during the examination 1. USSR author's certificate No. 580536, cl. G 01 R 33/08, 1977,

2. Authors certificate of the USSR 525902, cl. G 01 R 33/02, 1976.

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