RU2705747C1 - Complex of devices for measuring parameters of mechanical oscillations of high-temperature objects - Google Patents

Abstract

FIELD: instrument engineering.

SUBSTANCE: set of devices relates to instrument-making and can be used for remote monitoring of operability of means of measuring parameters of mechanical oscillations, mainly high-temperature objects. System comprises two devices – a measuring-amplifying unit and a recording unit. Measuring and amplifying unit includes a piezoelectric vibration transducer mounted on the object, a cable communication line with an end connector, as well as an amplifying-converting unit, a reference voltage source and a low-pass filter placed on the board installed in the end connector. Cable communication line connects the output of the piezoelectric vibration transducer through the input resistor with the inverting input of the differential operational amplifier, which forms the basis of the amplifying-converting unit. Recording unit includes a power supply, an output voltage divider, an AC voltage recorder, a three-channel two-position switch, a storage unit, a comparator unit, a fault indicator and a test signal source. Test signal source in the operability test mode of the complex is connected through the third output terminal of the end connector and the low-pass filter capacitor to the non-inverting input of the differential operational amplifier. Placing in the end connector at a considerable distance from the measurement object sensitive to high (low) temperature radioelectronic elements of the measuring-amplifying unit leads to exclusion of their thermal contact with the measurement object and, respectively, to expansion of operating temperature range when measuring vibration parameters, which in this case is determined only by operating characteristics of used piezoelectric vibration transducer.

EFFECT: technical result consists in providing the possibility of remote verification by determining compliance of output parameters of the piezoelectric vibration transducer and amplifier-converting unit to the set values when exposed to a test electric signal.

1 cl, 1 tbl, 3 dwg

Description

A set of devices relates to the field of instrumentation and can be used to remotely monitor the health of measuring instruments for measuring the parameters of mechanical vibrations, mainly of high-temperature objects.

Piezoelectric vibration transducers are widely used in measuring instruments for the parameters of mechanical vibrations (vibrations), which are designed to operate for long periods of time with minimal maintenance in harsh operating conditions (elevated temperature, humidity, aggressive environment, etc.). For this reason, it may cause malfunctions or deviations from the characteristics of piezoelectric vibration transducers normalized in regulatory documents and, as a result, the measurement of vibration parameters will be carried out with significant errors (exceeding the permissible limits) or there will be no information about them at all. In such cases, failure of the object is possible, the vibrational parameters of which are intended to measure a set of devices with a piezoelectric vibration transducer. Replacing a failed piezoelectric vibration transducer is often an expensive operation (and sometimes it is simply not possible without lengthy and costly work), therefore, periodic monitoring of the performance of measuring instruments with a piezoelectric vibration transducer installed at the measuring object with elevated temperature is an urgent task.

Known technical solution for measuring the parameters of mechanical vibrations of objects with high temperature ("Piezoelectric accelerometer" RU 2097772, G01P 15/09, 1997.11.27).

The known technical solution comprises a piezoelectric vibration transducer, a preamplifier with a matching circuit, bipolar and field-effect transistors, a cable communication line with an end connector, a power source and a recorder. The preamplifier is divided into two parts, one of which with the matching circuit and bipolar and field-effect transistors is located together with the piezoelectric transducer in its case, and the other part of the preliminary amplifier, with the matching resistor, is located outside the piezoelectric vibration transducer and connected to its first part with a communication line with end connector.

Placing the second part of the pre-amplifier with a matching resistor that determines the operation mode and gain of the pre-amplifier in normal temperature conditions allows the known technical solution to be operational in the temperature range of the object from -40 to + 125 ° C.

The disadvantage of the known technical solution is the lack of the ability to remotely monitor its performance.

There is also known a technical solution for measuring the parameters of mechanical vibrations of high-temperature objects ("Piezoelectric accelerometer" RU 140046 U1, G01P 15/09, 10/17/2013), which allows you to measure the parameters of mechanical vibrations of objects with high temperature (from -60 to + 250 ° C, and when using high-temperature piezoceramics - up to + 400 ° C), which, in combination with the essential features, is the closest analogue of the claimed invention.

The known technical solution (Fig. 1) contains a measuring amplifier unit 1 and a recording unit 2. The measuring amplifier unit 1 includes a piezoelectric vibration transducer 3, in the housing of which a piezo transducer 3 ₁ is placed. The piezoelectric vibration transducer 3 is installed on the object 4, the vibration acceleration of which is measured during operation. A cable communication line 5 with an end connector 6 is connected to the signal output terminal 3 _{2 of the} piezoelectric transducer 3 ₁ , in which a board 10 with an amplifying-converting unit 9, a low-pass filter 15 and a reference voltage source 16 is installed. Output contacts 6 ₁ and 6 _{2 of the} terminal connector 6, which are the current output of the amplifier-converting unit 9, are connected respectively to the power bus 12 and the common bus 13. The second common output contact 3 _{3 of the} piezoelectric transducer 3 _{1 is} connected to the housing of the vibration transducer 3 and the common bus 13.

The amplifying and converting unit 9 is made on the basis of a differential operational amplifier 8 (the negative feedback circuits in Fig. 1 are not shown), the inverting input 8 _{1 of} which is connected via a cable communication line 5 through an input resistor 7 to a signal output contact 3 _{2 of the} piezo transducer 3 ₁ and the output 8 _{2 of the} differential operational amplifier 8 is connected to the base 11 _{1 of the} transistor 11 structure pn-p. The emitter 11 ₂ and the collector 11 _{3 of the} transistor 11, as well as the power leads 8 ₃ and 8 _{4 of the} differential operational amplifier 8 through the outputs 9 ₁ and 9 _{2 of the} amplifier-converting unit 9 are connected respectively to the power bus 12 and to the common bus 13.

To the non-inverting input 8 _{5 of the} differential operational amplifier 8 is connected through a resistor 14 of the low-pass filter 15, the reference voltage source 16 and the first output 17 _{1 of the} capacitor 17 of the low-pass filter 15, which is connected to the common bus 13 by the second output 17 ₂ .

In the registration unit 2, a DC source 18, an AC output divider 19, and an AC voltage recorder 22 are located. The first terminal 18 _{1 of the} DC power source 18 is connected to the power bus 12, and the second terminal 18 ₂ to the common bus 13.

The output voltage divider 19 contains a series-connected capacitor 20 and a resistor 21, while the midpoint between them 19 _{1 is} connected to the input of the AC voltage recorder 22, the output 20 _{1 of the} capacitor 20 is connected to the power bus 12, and the output 21 _{1 of the} resistor 21 is connected to the common bus 13.

The power supply of the reference voltage source 16 is provided from a direct current source 18 through a limiting resistor 29 connected to a power bus 12.

Known technical solution works as follows.

The impact on the body of the piezoelectric vibration transducer 3 of external vibration from the side of the object 4 causes the appearance on the piezoelectric transducer 3 _{1 of an} electric charge proportional to the vibration acceleration acting on the body of the piezoelectric vibration transducer 3. An electric charge is transmitted through the cable resistor 7 through the input resistor 7 to the inverting input 8 _{1 of the} differential operating an amplifier 8 of an amplifier-converting unit 9 located on the board 10 in the end connector 6. The electric charge of the conversion It is connected to an electric voltage, which is amplified in the differential operational amplifier 8 of the amplifying-converting unit 9 and arrives at the base 11 _{1 of the} transistor 11 of the pn-p structure.

Changing the internal resistance of transistor 11 under the influence of voltage at base 11 ₁ causes the voltage drop to be modulated at the junction of “emitter 11 ₁ - collector 11 ₂ ” of transistor 11. The amplified modulated signal in the form of the sum of constant and variable voltage components is supplied through terminals 6 ₁ and 6 _{2 of the} terminal connector 6 to an output AC voltage divider 19, which, using a capacitor 20 and a resistor 21 of the output AC voltage divider 19, isolates the AC voltage component from the midpoint ki 19 _{1 of the} output AC voltage divider 19 to the AC voltage recorder 22. The amplitude (or RMS value) of the voltage measured by the AC voltage recorder 22 is proportional to the amplitude (or RMS value) of the vibration acceleration acting on the piezoelectric vibration transducer 3.

To select the operating point of the differential operational amplifier 8 of the amplifier-converting unit 9, a non-inverting input 8 ₅ is supplied with a constant voltage from the reference voltage source 16 through the resistor 14 and the low-pass filter capacitor 17. The power of the entire amplifier-converting unit 9 and the reference voltage source 16 is carried out from a direct current source 18, which ensures stabilization of the current consumption at a given level (for example, 4 mA).

The placement of temperature-sensitive electronic elements of a known technical solution (board 10) in the end connector 6 eliminates their thermal contact with the measurement object and, accordingly, expands the operating temperature range when measuring vibration parameters.

The disadvantage of the known technical solution is the lack of the ability to remotely monitor its performance.

The task to be solved by the claimed complex of devices for measuring the parameters of mechanical vibrations of high-temperature objects is to expand the functionality of the complex through the implementation of the ability to remotely verify its performance.

The technical result obtained by the implementation of the inventive complex of devices for measuring the parameters of mechanical vibrations of high-temperature objects, consists in remotely checking the correspondence of the output parameters of the piezoelectric vibration transducer and the amplifying transducer block to the established values when exposed to a test electric signal.

The specified technical result is achieved by the fact that in the claimed complex of devices for measuring the parameters of mechanical vibrations of high-temperature objects, containing a measuring and amplifying unit and a recording unit, while the measuring and amplifying unit contains a piezoelectric vibration transducer, in the body of which a piezoelectric transducer is located, the common output contact of which is connected with a vibro-converter housing and a common bus, a cable communication line with an end connector and a regis unit connected to it traction through two output contacts of the end connector, one of which is connected to the power bus, and the second to the common bus, located on the board installed in the end connector, an amplifier-converting unit based on a differential operational amplifier, the inlet input of which is connected through the input a resistor with a signal output contact of the piezoelectric transducer via a cable communication line, and the output - with the base of a transistor of the pnp structure, the emitter and collector of which, as well as the power leads of the differential opera of the amplifier through the first and second outputs of the amplifier-converter unit are connected respectively to the power bus and the common bus, a low-pass filter and a reference voltage source, the first output of which is connected through a low-pass filter resistor to a non-inverting input of the differential operational amplifier, and through a limiting resistor to power bus, the second output of the reference voltage source is connected to a common bus, the non-inverting input of the differential operational amplifier is also connected to the first output the low-pass filter capacitor house, the recording unit contains a direct current source, the terminals of which are connected through the two output contacts of the terminal connector to the power bus and the common bus of the measuring and amplifying unit, an alternating voltage output divider, including an output divider capacitor and an output divider resistor, at In this case, the first terminal of the output divider capacitor is connected to the power bus, the second terminal of the output divider resistor is connected to the common bus, and the midpoint between and connected to the input of the AC voltage recorder, in contrast to the known technical solution in the claimed complex, the end connector of the measuring and amplifying unit is equipped with an additional third output contact, an additional resistor is placed on the board installed in the end connector, and the recording unit is additionally equipped with a three-channel on / off switch, the source of the test signal, the storage unit, the comparison unit and the fault indicator, while the second output of the capacitor a low-frequency filter is connected to an additional third output contact of the end connector, and through an additional resistor to a common bus, the output of the AC voltage recorder is connected to the first and second channels of the three-channel on-off switch, the third channel of the three-channel on-off switch is connected to the additional third output contact of the end connector, the first and the second contacts of the first channel of the three-channel on-off switch are connected to the input of the storage unit, the output of which is connected to the first input of the comparison unit, the second contact of the second channel of the three-channel on-off switch is connected to the second input of the comparison unit, the first contact of the third channel of the three-channel on-off switch is connected to the common bus, and the second contact is to the output of the test signal source, moreover, the output of the comparison unit connected to the input of the malfunction indicator.

In FIG. 1 shows a block diagram of a prototype of the claimed complex of devices for measuring the parameters of mechanical vibrations of high-temperature objects.

In FIG. 2 shows a schematic diagram of a measuring and amplifying unit of the claimed complex.

In FIG. 3 shows a block diagram of a registration unit of the claimed complex.

The complex of devices for measuring the parameters of mechanical vibrations of high-temperature objects (Fig. 2 and Fig. 3) contains the first device - measuring and amplifying unit 1 and the second device - registration unit 2.

The measuring and amplifying unit 1 is a piezoelectric vibrator 3, which is placed in the housing _1, a piezoelectric transducer 3. The piezoelectric vibration transducer 3 is installed on the object 4, the vibration acceleration of which is measured during operation. The signal output pin 3 _{2 of the} piezoelectric transducer 3 _{1 is} connected by a cable communication line 5 with an end connector 6, connecting the output pin 3 _{2 of the} piezoelectric vibro-transducer 3 through the input resistor 7 with the inverting input 8 _{1 of the} differential operational amplifier 8 (the negative feedback circuit in Fig. 2 is not shown) amplifying and converting unit 9 placed on the board 10 installed in the connector terminal 6. The output ₈ February differential operational amplifier 8 amplifying and converting unit 9 Cpd ene with a base 11 of transistor ₁₁ January pn-p structure. The emitter 11 ₂ and the collector 11 _{3 of the} transistor 11 and the terminals 8 ₃ and 8 _{4 of the} differential operational amplifier 8 through the outputs 9 ₁ and 9 _{2 of the} amplifier-converter unit 9 are connected respectively to the power bus 12 and to the common bus 13, to which the contacts are also connected 6 ₁ and 6 _{2 of} end connector 6.

The common output contact 3 _{3 of the} piezoelectric transducer 3 _{1 is} connected to the housing of the vibration transducer 3 and a common bus 13.

The non-inverting input 8 _{5 of the} differential operational amplifier 8 is connected via a low-pass filter resistor 14 to a reference voltage source 16 and a first output 17 _{1 of} a low-pass filter capacitor 17. Elements of a low-pass filter 15 and a reference voltage source 16 are located on the board 10.

The power source of the complex blocks devices 1 and 2 serves as a constant current source 18, which terminal 18 ₁ is connected to power bus 12 through the output terminal 6 ₁ terminal connector 6, and the terminal 18 ₂ - to the common bus 13 through the output terminal 6 ₂ terminal connector 6.

The output AC voltage divider 19, contains a capacitor 20 and a resistor 21 connected in series, the midpoint between them - 19 _{1 is} connected to the input of the AC voltage recorder 22. The output 20 _{1 of the} capacitor 20 is connected to the power bus 12, and the output 21 _{1 of the} resistor 21 is connected to the common the bus 13. The output of the AC voltage recorder 22 is connected to two channels 23 ₁ and 23 _{2 of a} three-channel _on -off switch 23.

The contacts 23 _1-1 and 23 _{1-2 of the} first channel 23 _{1 of the} three-channel _on -off switch 23 are connected to the input of the storage unit 24, the output of which is connected to the first input 25 ₁ of the comparison unit 25, the contact 23 _{2-2 of the} second channel 23 _{2 of the} three-channel on-off switch 23 connected to the second input 25 ₂ of the comparison unit 25, the output of which is connected to the input of the fault indicator 26.

The second terminal 27 _{1 of the} additional resistor 27 is connected to the second terminal 17 _{2 of the} low-pass filter capacitor 15 and, through the output pin 6 of the ₃ end connector 6, the third channel 23 _{3 of the} three-channel on-off switch 23. The second terminal 27 _{2 of the} additional resistor 27 is connected to the common bus 13 .

Contact 23 _{3-1 of the} third channel 23 _{3 of the} three-channel on-off switch 23 is connected to a common bus 13, and contact 23 _3-2 to the output of the test signal source 28.

The power supply of the reference voltage source 16 is provided from a direct current source 18 through a limiting resistor 29 connected to a power bus 12.

A set of devices for measuring the parameters of mechanical vibrations of high-temperature objects works as follows.

The piezoelectric vibration transducer 3 is installed on the object 4, the vibration acceleration of which is measured during operation. Using a cable communication line 5, the end connector 6 with the board 10 is installed at a considerable distance from the object 4, which significantly reduces the influence of the temperature of the object 4 on the electronic elements placed on the board 10.

In the vibration acceleration measurement mode, the three-channel on-off switch 23 is set to the first position (the channels of the three-channel on-off switch 23 are connected to the first contacts: 23 _1-1 , 23 _2-1 , 23 _3-1 ; the switch position shown in Fig. 3). The impact on the piezoelectric vibration transducer 3 of external vibration from the side of the object 4 causes the appearance of an electric charge on the piezoelectric transducer 3 ₁ proportional to the vibration acceleration acting on it from the side of the object 4. On a cable communication line 5, the electric charge from the piezoelectric transducer 3 ₁ enters through the input resistor 7 to the inverting input 8 _{1 of the} differential operational amplifier 8 of the amplifier-conversion unit 9, located on the board 10 in the end connector 6. The electric charge is amplified in the differential operational amplifier 8, is converted into electrical voltage and enters the base 11 _{1 of the} transistor 11 structure pn-p.

A change in the internal resistance of transistor 11 under the influence of voltage at the base 11 ₁ causes modulation of the voltage drop at the junction "emitter 11 ₁ - collector 11 ₂ " of the transistor 11.

The amplified modulated signal in the form of the sum of the constant and variable voltage components is supplied through the contacts 6 ₁ and 6 _{2 of the} end connector 6 to the AC output divider 19. The capacitor 20 with the resistor 21 of the output divider 19 isolated the alternating voltage component, which from the midpoint 19 _{1 of the} output divider 19 is supplied to the recorder alternating voltage 22, the output of which through contacts 23, _1-1 and _1-2 of the first channel 23, January ₂₃ three-way toggle switch 23 - to the input of the storage unit 24. Amplias yes (or RMS) voltage measured registrar alternating voltage 22, proportional to the amplitude (or RMS) vibration acceleration acting on the piezoelectric vibrator 3.

The choice of the operating point of the differential operational amplifier 8 is made using the reference voltage source 16 connected through a resistor 14 of the low-pass filter 15 with a non-inverting input 8 _{5 of the} differential operational amplifier 8 of the amplifier-converting unit 9.

Power amplifier-converting unit 9 and the reference voltage source 16 is provided from a constant current source 18, which ensures stabilization of the current consumption at a given level (for example, 4 mA).

The health check of a set of devices for measuring the parameters of mechanical vibrations of high-temperature objects is carried out as follows.

). Измеренное регистратором переменного напряжения 22 значение амплитуды (или среднего квадратического значения) переменного напряжения, которое пропорционально действующему на пьезоэлектрический вибропреобразователь 3 эталонному виброускорению, поступает на первый 23₁ и второй 23₂ каналы трехканального двухпозиционного переключателя 23. С первого канала 23₁ трехканального двухпозиционного переключателя 23 напряжение поступает на контакт 23_1-1 и на вход запоминающего блока 24, где определяется, а затем и фиксируется в паспорте комплекса действительное значение коэффициента преобразования (пКл/мс^-2) пьезоэлектрического вибропреобразователя 3 на базовой частоте (например, 160 Гц), определяемое по формуле, пКл/мс^-2,During the initial calibration, in accordance with GOST 8.669-2009, the piezoelectric vibration transducer 3 of the complex is installed on the vibration table of the working standard of units of vibration parameters. All units of the device complex in accordance with FIG. 2 and FIG. 3. The channels of the three-channel on-off switch 23 are switched to the first position. On the vibration table of the working standard of units of vibration parameters, the reference value of the amplitude (or root mean square value) of vibration acceleration (for example,

) Measured by the alternating voltage recorder 22, the amplitude (or root mean square value) of the alternating voltage, which is proportional to the reference vibration acceleration acting on the piezoelectric vibration transducer 3, is supplied to the first 23 ₁ and second 23 ₂ channels of the three-channel on-off switch 23. From the first channel 23 _{1 on the} three-channel _on -off switch 23 voltage is supplied to contact 23 _1-1 and to the input of the storage unit 24, where it is determined and then fixed in the passport of the complex the positive value of the conversion coefficient (pCl / ms ^-2 ) of the piezoelectric vibration transducer 3 at the base frequency (for example, 160 Hz), determined by the formula, pCl / ms ^-2 ,

- амплитудное значение (или среднее квадратическое значение) напряжения в средней точке 19₁ выходного делителя переменного напряжения 19, измеренное с помощью регистратора переменного напряжения 22, мВ;Where

- the amplitude value (or root mean square value) of the voltage at the midpoint 19 _{1 of the} output AC voltage divider 19, measured using an AC voltage recorder 22, mV;

- амплитудное значение (или среднее квадратическое значение) виброускорения, задаваемого с помощью рабочего эталона единиц параметров вибрации, мс^-2;

- the amplitude value (or root mean square value) of vibration acceleration, set using the working standard units of vibration parameters, ms ^-2 ;

- значение емкости конденсатора в цепи отрицательной обратной связи дифференциального операционного усилителя 8 усилительно-преобразующего блока 9 (на фиг. 1 и фиг. 2 конденсатор не показан, значение емкости этого конденсатора указывается в паспорте на комплекс устройств), нФ.

- the value of the capacitor in the negative feedback circuit of the differential operational amplifier 8 of the amplifier-converting unit 9 (the capacitor is not shown in Fig. 1 and Fig. 2, the capacitance value of this capacitor is indicated in the passport for the set of devices), nF.

в средней точке 19₁ выходного делителя переменного напряжения 19, измеренное регистратором переменного напряжения 22.In the storage unit 24 is also recorded the amplitude value (or root mean square value) of the voltage

at the midpoint 19 _{1 of the} output AC voltage divider 19, measured by the AC voltage recorder 22.

на выходе источника тестового сигнала 28, соответствующее действующему на пьезоэлектрический вибропреобразователь значению амплитуды (или среднему квадратическому значению) виброускорения, при котором во время первичной поверки определялось действительное значение коэффициента преобразования пьезоэлектрического вибропреобразователя 3 (например,

).After installation of the piezoelectric vibration transducer 3 at the place of operation, all units of the device complex are connected in accordance with FIG. 2 and FIG. 3, transfer the three-channel on-off switch 23 to the second position (the contacts of the channels 23 _1-2 , 23 _2-2 and 23 _{3-2 are} connected), feed from the source of the test signal 28 at the base frequency through the capacitor 17 of the low-pass filter 15 an alternating voltage to a non-inverting input 8 _{5 of the} differential operational amplifier 8 of the amplifier-transforming unit 9 and select the initial amplitude (or root mean square) voltage value

at the output of the source of the test signal 28, corresponding to the value of the amplitude (or root mean square value) of the vibration acceleration acting on the piezoelectric vibration transducer, during which the actual value of the conversion coefficient of the piezoelectric vibration transducer 3 (for example,

)

(допустимо при незначительном превышении шумового порога напряжением

увеличивать

таким образом, чтобы амплитудное значение (или среднее квадратическое значение) напряжения в средней точке 19₁ выходного делителя переменного напряжения 19 было кратно значению

(например,

или

). Частота сигнала на выходе источника тестового сигнала 28 должна быть равна частоте сигнала, при которой определялось действительное значение коэффициента преобразования пьезоэлектрического вибропреобразователя 3 (например, 160 Гц).In this case, the amplitude value (or root mean square value) of the voltage at the midpoint 19 _{1 of the} output voltage divider AC 19 should be equal

(permissible when the voltage threshold is slightly exceeded

increase

so that the amplitude value (or root mean square value) of the voltage at the midpoint 19 _{1 of the} output voltage divider of the alternating voltage 19 is a multiple of the value

(eg,

or

) The frequency of the signal at the output of the source of the test signal 28 should be equal to the frequency of the signal at which the actual value of the conversion coefficient of the piezoelectric vibration transducer 3 (for example, 160 Hz) was determined.

(и кратность напряжения

если оно применялось) сохраняется в запоминающем устройстве 24 и фиксируется в паспорте комплекса. При фиксированном значении

изменяют частоту источника тестового сигнала 28 от базового значения до величины 1,2 F_Уст, где F_Уст - значение частоты установочного резонанса, которое должно соответствовать указанному в паспорте

на пьезоэлектрический вибропреобразователь 3 (отличие не должно превышать, например, 10%). В запоминающем блоке 24 фиксируют значение F_Уст и амплитуду сигнала на выходе регистратора переменного напряжения 22 на частоте F_Уст (или среднее квадратическое значение).Voltage value

(and voltage multiplicity

if it was used) is stored in the storage device 24 and is recorded in the passport of the complex. At a fixed value

change the frequency of the source of the test signal 28 from the base value to a value of 1.2 F _Ust , where F _Ust is the value of the frequency of the installation resonance, which must correspond to that specified in the passport

to a piezoelectric vibration transducer 3 (the difference should not exceed, for example, 10%). In the memory unit 24 the value F is fixed and _Set amplitude at the output AC voltage recorder 22 at frequency F _Set (or RMS value).

The three-channel on-off switch 23 is moved to the first position, after which the complex of devices is ready for operation in the vibration acceleration measurement mode.

Information about the current amplitude value (or mean square value) of vibration acceleration acting on the piezoelectric vibration transducer 3 from the side of the object 4, is obtained from the voltage measured by the variable voltage recorder 22, according to the formula,

- текущее амплитудное значение (или среднее квадратическое значение) напряжения в средней точке 19₁ выходного делителя переменного напряжения 19, измеренное с помощью регистратора переменного напряжения 22, мВ;Where

- the current amplitude value (or root mean square value) of the voltage at the midpoint 19 _{1 of the} output AC voltage divider 19, measured using an AC voltage recorder 22, mV;

- текущее амплитудное значение (или среднее квадратическое значение) виброускорения, действующего на пьезоэлектрический вибропреобразователь 3 со стороны объекта 4, мс^-2.

- the current amplitude value (or root mean square value) of vibration acceleration acting on the piezoelectric vibration transducer 3 from the side of the object 4, ms ^-2 .

В средней точке 19₁ выходного делителя переменного напряжения 19 текущее амплитудное значение (или среднее квадратическое значение) сигнала

измеряется регистратором переменного напряжения 22 и передается через контакт 23_2-2 трехканального двухпозиционного переключателя 23 на второй вход 25₂ блока сравнения 25, в котором текущее амплитудное значение (или среднее квадратическое значение) сигнала

сравнивается с сохраненным в запоминающем блоке 24 значением

При сравнении измеренных и сохраненных в запоминающем блоке 24 значений напряжения возможны несколько вариантов.Through the time interval regulated in the normative documentation for a set of devices for measuring the parameters of mechanical vibrations of high-temperature objects, they will check its operability. For this converted three-way two-position switch 23 to a second position and through a capacitor 17 the low pass filter is fed to the non-inverting input ₈ May differential operational amplifier 8 amplifying and converting unit 9 an electrical signal at the base frequency output from the test signal source 28, an amplitude value (or RMS value) which is equal to the value recorded in the passport of the complex

At the midpoint 19 _{1 of the} output voltage divider 19, the current amplitude value (or root mean square value) of the signal

measured by an alternating voltage recorder 22 and transmitted through contact 23 of a _2-2 three-channel on-off switch 23 to a second input 25 ₂ of a comparison unit 25 in which the current amplitude value (or mean square value) of the signal

compared with the value stored in the storage unit 24

When comparing the voltage values measured and stored in the memory unit 24, several options are possible.

1. If in the block comparison 25

(the deviation should not exceed the value specified, for example, for a complex of devices, for example, 5%), then the malfunction indicator 26 receives a command about the working condition of the complex of devices for measuring the parameters of mechanical vibrations of high-temperature objects.

2. If in the block comparison 25 condition

and the deviation exceeds the value regulated in the regulatory documents for the device complex, then the malfunction indicator 26 receives a command about the malfunctioning state of the device complex.

3. If in the block comparison 25 conditions are met:

then the output contacts 3 ₂ and / or 3 _{3 of the} piezoelectric transducer 3 ₁ were disconnected from the cable communication line 5 or the cable communication line 5 itself was broken. The malfunction indicator 26 receives a command about the malfunctioning state of the device complex.

пьезоэлектрического вибропреобразователя 3. Для этого при фиксированном значении

изменяют частоту источника тестового сигнала 28 от базового значения (например, 160 Гц) до величины 1,2 F_Уст, где

- значение частоты установочного резонанса, сохраненное в запоминающем блоке 24 (отличие

не должно превышать заданного значения, например, 10%). При отсутствии отклонений, превышающих заданные значения, в индикатор неисправности 26 поступает команда об исправном состоянии комплекса устройств для измерения параметров механических колебаний высокотемпературных объектов.4. If the condition of paragraph 1 is satisfied, then using the source of the test signal 28, the current value of the frequency of the installation resonance is checked

piezoelectric vibration transducer 3. For this, at a fixed value

change the frequency of the source of the test signal 28 from the base value (for example, 160 Hz) to a value of 1.2 F _Set where

- the value of the frequency of the installation resonance stored in the storage unit 24 (difference

must not exceed a predetermined value, e.g. 10%). In the absence of deviations exceeding the specified values, the fault indicator 26 receives a command about the working condition of a set of devices for measuring the parameters of mechanical vibrations of high-temperature objects.

When registering a malfunction of the complex, further actions by the operator are associated with determining the source of the malfunction.

At our enterprise, 3 prototypes (No. 17114, 17117 and 17118) of the claimed complex of devices for measuring the parameters of mechanical vibrations of high-temperature objects with the following elements were manufactured:

- piezoelectric vibration transducers with shear deformation of piezoelectric elements (according to patent RU 143487 U1), in which

- the piezoelectric transducer (pos. 3 ₁ , see Fig. 2 and Fig. 3) has:

a piezo package containing 4 rectangular piezoceramic plates,

made of material TsTS-26, TNAV - 1;

sizes of rectangular piezoceramic plates - 8.5 × 8 mm ² ;

thickness - 0.72 mm; inertial mass - 15 g;

- differential operational amplifier - AD8627 (item 8):

- voltage reference source - AD1580BRT (item 16);

- transistor - ВС860С (pos. 11);

- DC power supply - LM334Z (pos. 18);

- AC voltage recorder - Agilent 34401A voltmeter (pos. 22);

- resistor - P1-33-1-1 (200 Ohms) (item 7);

- resistor - P1-33-1-1 (10 MOhm) (pos. 14);

- resistor - P1-33-1 (1 MOhm) (pos. 21);

- resistor - P1-33-1-1 (1 kOhm) (pos. 27);

- resistor - P1-33-1-1 (30 kOhm) (pos. 29);

- capacitor - K10-43 (0.33 μF); (item 17)

- capacitor - K10-43 (10 μF) (item 20).

Electronic elements with an amplifying-converting unit 9, a low-pass filter 15 and a reference voltage source 16 are mounted on a double-sided printed circuit board 10 with dimensions 10 × 11 mm ² using surface-mounted chip elements and placed in the end connector 6 (cable length from the piezoelectric vibration transducer 3 to board 10 from 0.6 to 1 m). Board 10 is placed between the contacts of the end connector 6 type 2RMDT18KPE4G5V1V. To ensure the tightness of the end connector 6 is used sealant "VIKSINT." The design of the end connector 6 with the board 10 located in it allows measurements at temperatures whose boundaries are determined only by the operational characteristics of the used piezoelectric transducer 3 ₁ (see, for example, the piezoelectric vibration transducer MV-44 number in the State Register of Measuring Instruments of the Russian Federation 21349-06 dated 15.03. 2012, in which the temperature operating conditions, ° C from minus 60 to plus 400).

The sequence of experiments with each sample of the device complex is as follows.

и значение частоты установочного резонанса

которые фиксируются в запоминающем блоке 24 вместе со средним квадратическим значением напряжения на выходе регистратора переменного напряжения

In accordance with the recommendations of GOST R 8.669 - 2009, the actual value of the conversion coefficient of the piezoelectric vibration transducer is determined

and the frequency of the installation resonance

which are fixed in the storage unit 24 together with the root mean square voltage value at the output of the AC voltage recorder

The piezoelectric vibration transducer 3 was installed on the simulator of object 4 (the inertial mass of which is 10 times the mass of the piezoelectric vibration transducer 3) and all units of the device complex were connected in accordance with FIG. 2 and FIG. 3.

The procedure described above was determined

при котором среднее квадратическое значение напряжения в средней точке 19₁ выходного делителя переменного напряжения 19 равно сохраненному в запоминающем блоке 24 напряжению

(в эксперименте

),- the mean square value of the voltage at the output of the source of the test signal 28

at which the mean square value of the voltage at the midpoint 19 _{1 of the} output divider of the alternating voltage 19 is equal to the voltage stored in the storage unit 24

(in experiment

),

(отличие не должно превышать 5%).- the value of the frequency of the installation resonance F _Set , which should be equal

(difference should not exceed 5%).

и

(при

) и влияние обрыва соединения в линии передачи электрического сигнала от пьезоэлектрического вибропреобразователя 3 к расположенной в концевом соединителе 6 плате 10.At the next stage, the experimental samples of the piezoelectric vibration transducer 3, which is part of the device complex, were subjected to the polarization procedure (they were subjected to a constant voltage of 500 to 1000 V), after which the current values were determined

and

(at

) and the effect of a broken connection in the transmission line of an electric signal from a piezoelectric vibration transducer 3 to a board 10 located in the end connector 6.

The experimental results are shown in the table.

It follows from the table that, after exposure to experimental samples of piezoelectric vibration transducers with a constant voltage of 500 to 1000 V (after polarization), the alternating voltage at the output of the amplifier-converting unit 9 and measured by the alternating voltage recorder 22 at the midpoint 19 ₁ of the alternating voltage output divider 19 changed ~ -8% when applying a voltage of 100 mV (root mean square value) to the non-inverting input 8 of the ₅ differential operational amplifier 8 from the output of the test signal source 28. Since the conversion coefficient of the amplifier-transforming unit 9 has not changed, a change in the voltage at the output of the amplifier-transforming unit 9 confirms the change in the conversion coefficients of the piezoelectric vibration transducers, which indicates their malfunctioning state.

При этом, напряжение, измеренное регистратором напряжения 22 в средней точке 19₁ выходного делителя переменного напряжения 19,When simulating a broken connection in the transmission line of an electric signal from a piezoelectric vibration transducer 3 to a board 10 located in the end connector 6 with an amplifier-converter unit 9, the voltage at the output of the amplifier-converter unit 9 was within

Moreover, the voltage measured by the voltage recorder 22 at the midpoint 19 _{1 of the} output voltage divider AC voltage 19,

но

but

This indicates that the output contacts 3 ₂ and / or 3 _{3 of the} piezoelectric transducer 3 ₁ disconnected from the cable communication line 5 or an open circuit of the cable communication line 5 itself.

Thus, it is seen that the above information confirms the possibility of implementing the invention, achieving the specified technical result and solving the problem.

Claims (1)

A set of devices for measuring the parameters of mechanical vibrations of high-temperature objects, comprising a measuring and amplifying unit and a recording unit, while the measuring and amplifying unit contains a piezoelectric vibration transducer, in the housing of which there is a piezoelectric transducer, the common output contact of which is connected to the vibration transducer housing and a common bus, a cable communication line with an end connector and a registration unit connected to it through two output contacts of an end connector, one of which of which is connected to the power bus, and the second to the common bus, located on the board installed in the end connector, an amplifier-converter unit based on a differential operational amplifier, the inlet input of which is connected through the input resistor to the signal output contact of the piezoelectric transducer via a cable communication line , and the output is with the base of a transistor of the pn-p structure, the emitter and collector of which, as well as the power leads of the differential operational amplifier through the first and second outputs of the amplifier-transformer of the connecting unit are connected respectively to the power bus and the common bus, a low-pass filter and a reference voltage source, the first output of which is connected through a low-pass filter resistor to a non-inverting input of a differential operational amplifier, and through a limiting resistor - to a power bus, the second output of the reference voltage source is connected with a common bus, the non-inverting input of the differential operational amplifier is also connected to the first output of the low-pass filter capacitor, the recording unit contains and a DC current source, the terminals of which through two output contacts of the terminal connector are connected to the power bus and the common bus of the measuring and amplifying unit, an alternating voltage output divider including a series-connected capacitor of the output divider and a resistor of the output divider, while the first output of the capacitor of the output divider is connected to power supply bus, the second output of the output divider resistor is connected to the common bus, and the middle point between them is connected to the input of the AC voltage recorder, excellent in that the end connector of the measuring and amplifying unit is equipped with an additional third output contact, an additional resistor is placed on the board installed in the end connector, and the recording unit is additionally equipped with a three-channel on / off switch, a test signal source, a memory unit, a comparison unit and a fault indicator, the second output of the low-pass filter capacitor is connected to an additional third output contact of the end connector, and through the resistor is with a common bus, the output of the AC voltage recorder is connected to the first and second channels of the three-channel on-off switch, the third channel of the three-channel on-off switch is connected to an additional third output contact of the end connector, the first and second contacts of the first channel of the three-channel on-off switch are connected to the input of the storage unit, the output of which is connected to the first input of the comparison unit, the second contact of the second channel of the three-channel two-position This switch is connected to the second input of the comparison unit, the first contact of the third channel of the three-channel on / off switch is connected to the common bus, and the second contact is connected to the output of the test signal source, and the output of the comparison unit is connected to the input of the malfunction indicator.

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