A standard voltage / charge converter calibration device

Abstract

The present invention discloses a standard voltage / charge converter calibration device, which relates to the technical field of charge amplifier measurement and calibration, in order to solve the problem that the existing calibration device cannot ensure the uniformity of its value and the measurement result is unstable. It includes a standard voltage / charge converter, a function generator, a digital multimeter and a capacitance tester; the function generator is connected to the signal input end of the standard voltage / charge converter to provide an excitation signal for the standard voltage / charge converter, the digital multimeter is connected to the DC amplifier module and the attenuator module of the standard voltage / charge converter to calibrate the DC amplifier and the attenuator, and the capacitance tester is connected to the test capacitor module of the standard voltage / charge converter to calibrate the capacitor. The above calibration device is simple to operate, saves hardware costs, effectively solves the problem of standard voltage / charge converter value traceability, and has high practicality.

Description

Technical Field

[0001] The invention relates to the technical field of charge amplifier metrology calibration, and in particular to a standard voltage / charge converter calibration device. Background Art

[0002] The charge amplifier is a preamplifier of the piezoelectric sensor. Its output voltage is proportional to the input charge. The charge amplifier is widely used in non-electrical measurement such as vibration, impact, force, pressure, and sound intensity. According to the requirements of the JJG338-2013 charge amplifier verification procedure, a standard voltage / charge converter is required in the standard instrument for the metrological verification of the charge amplifier to transfer its value. However, there has been no unified method and specification in China for the value traceability of the standard voltage / charge converter itself. At present, the calibration methods of the standard voltage / charge converters produced by various manufacturers are compiled by the manufacturers themselves, and some do not even have corresponding calibration methods. It is impossible to guarantee the uniformity of their values ​​and the stability and reliability of the measurement results. Summary of the invention

[0003] The object of the present invention is to provide a standard voltage / charge converter calibration device, which is used to solve the problem that the existing calibration device cannot ensure the uniformity of its value and the measurement result is unstable.

[0004] In order to achieve the above object, the present invention provides the following technical solutions: a standard voltage / charge converter calibration device is provided, comprising a standard voltage / charge converter, a function generator, a digital multimeter and a capacitance tester;

[0005] The function generator is connected to the signal input terminal of the standard voltage / charge converter to provide an excitation signal for the standard voltage / charge converter. The digital multimeter is connected to the DC amplifier module and the attenuator module of the standard voltage / charge converter to calibrate the DC amplifier and the attenuator. The capacitance tester is connected to the test capacitor module of the standard voltage / charge converter to calibrate the capacitor.

[0006] The standard voltage / charge converter calibration device provided by the present invention can effectively calibrate different parameters of the standard voltage / charge converter through a function generator, a digital multimeter and a capacitance tester. The calibration device is convenient and quick to assemble, has high device stability, small measurement uncertainty, and the measurement result is consistent with the theoretical calculated value. The operation is simple and can be achieved by using a general function generator, a digital multimeter and a capacitance tester, thus saving hardware costs, effectively solving the problem of standard voltage / charge converter value traceability, and having high practicality.

[0007] Preferably, in the above technical solution, when calibrating the standard voltage of the standard voltage / charge converter, the amplifier / calibration capacitor interface of the standard voltage / charge converter is connected to the voltage input terminal of the digital multimeter, the digital multimeter is in DCV test mode, the calibration amplifier switch of the standard voltage / charge converter is in a triggered state, the input-output switch is in the left position, triggering the ground, +1V, -1V buttons to complete the corresponding nominal voltage calibration.

[0008] Preferably, in the above technical solution, when calibrating the nominal DB of the standard voltage / charge converter, the function trigger output is connected to the signal source output port of the standard voltage / charge converter, the voltmeter input / amplifier is connected to the voltage input of the digital multimeter, the calibration amplifier of the standard voltage / charge converter is triggered, the input-output switch is in the left position, the AC switch is in the trigger state, the function generator outputs an excitation signal, and the output signal of the function generator measured by the ACV gear of the digital multimeter is the voltage value of the signal source output of the standard voltage / charge converter.

[0009] Preferably, in the above technical solution, when calibrating the attenuator of the standard voltage / charge converter, the voltage input terminal of the digital multimeter is connected to the amplifier / calibration capacitor interface of the standard voltage / charge converter, the function generator is connected to the signal source output of the standard voltage / charge converter, the function generator provides an excitation signal for the standard voltage / charge converter, and the digital multimeter measures the attenuation voltage values ​​of the standard voltage / charge converter in the switch triggering states of 0dB, -10dB, -20dB, -30dB, and -40dB at different frequencies, and calculates the attenuation value.

[0010] Preferably, in the above technical solution, when calibrating the filter of the standard voltage / charge converter, the output port of the function generator is connected to the signal source output of the standard voltage / charge converter and outputs an excitation signal, the voltage input terminal of the digital multimeter is connected to the voltmeter input / amplifier and amplifier / calibration capacitor of the standard voltage / charge converter, the voltages connected to the voltmeter input terminal and the amplifier / calibration capacitor terminal are detected respectively, the 0dB of the standard voltage / charge converter and the calibration amplifier are triggered, the attenuation value is calculated, the voltages connected to the voltmeter input terminal and the amplifier / calibration capacitor terminal are measured, and the attenuation value is calculated.

[0011] Preferably, in the above technical solution, when calibrating the capacitance of the standard voltage / charge converter, the standard voltage / charge converter is in a power-off state, the H terminal, L terminal and ground wire of the capacitance tester are respectively connected to the amplifier / calibration capacitance, charge amplifier input and ground of the standard voltage / charge converter, the capacitance tester is grounded, and the calibration capacitance switch of the standard voltage / charge converter is triggered, and the 10pF, 100pF, 1nF, 10nF, and 0.1μF keys of the standard voltage / charge converter are triggered to measure each nominal capacitance value. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0013] Figure 1 This is a schematic diagram of the structure of a standard voltage / charge converter according to an embodiment of the present invention;

[0014] Figure 2 Schematic diagram of a standard voltage / charge converter calibration device in an embodiment of the present invention.

[0015] Reference numerals:

[0016] 1-standard voltage / charge converter, 2-calibration amplifier, 3-calibration capacitor, 4-amplifier (out) / calibration capacitor, 5-charge amplifier input, 6-input and output switch, 7-output, 8-connect to voltmeter input, 9-signal source output, 10-0dB, 11--10dB, 12--20dB, 13--30dB, 14--40dB, 15-ground, 16--1V, 17-+1V, 18-AC, 19-10pF, 20-100pF, 21-pF, 22-nF, 23-0.1μF, 24-function generator, 25-capacitance tester, 26-digital multimeter. DETAILED DESCRIPTION

[0017] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0020] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] See Figure 1 and Figure 2 The standard voltage / charge converter calibration device provided by the present invention comprises a standard voltage / charge converter, a function generator, a digital multimeter and a capacitance tester; the function generator is connected to the signal input terminal of the standard voltage / charge converter to provide an excitation signal for the standard voltage / charge converter, the digital multimeter is connected to the DC amplifier module and the attenuator module of the standard voltage / charge converter to calibrate the DC amplifier and the attenuator, and the capacitance tester is connected to the test capacitor module of the standard voltage / charge converter to calibrate the capacitor.

[0023] When implementing:

[0024] The output signal of the function generator is an analog signal, the frequency meets 100Hz~250kHz, and the output amplitude is ≥5mVrms. The measurement range of the digital multimeter meets the frequency of DC~300kHz, and the amplitude is ≤100Vrms. The measurement range of the capacitance tester meets the capacitance measurement range of 10pF~100nF. The cables connecting the input and output interfaces of each standard device and the standard voltage / charge converter are BNC connectors.

[0025] When calibrating a standard voltage / charge converter, it is divided into the following parts:

[0026] When calibrating to "nominal voltage":

[0027] The "amplifier (out) / calibration capacitor" 4 interface of the calibrated standard voltage / charge converter 1 is connected to the voltage input terminal of the digital multimeter 26 through a BNC cable. The digital voltmeter 26 is set to the DCV measurement mode, the "calibration amplifier" 2 switch is pressed, the input and output switch 6 is turned to the left, and the "ground" 15, "+1V" 16, and "-1V" 17 switches are pressed in sequence to use the digital multimeter to measure the "ground", "+1V", and "-1V" voltages respectively, to complete the calibration of the parameter "nominal voltage".

[0028] When calibrating for "Nominal dB (100Hz)":

[0029] The output port of the function generator 24 is connected to the "signal source output" 9 port of the calibrated standard voltage / charge converter 1, and the "voltmeter input / amplifier (in)" 4 port is connected to the voltage input terminal of the digital multimeter 26. The "calibration amplifier" 2 switch of the calibrated standard voltage / charge converter 1 is pressed, the input-output switch 6 is moved to the left, and the "AC" 18 switch is pressed. The function generator 24 is set to square wave, 100Hz, 5Vrms, and high-impedance state to output the signal. The voltage value of the "connected voltmeter input" 8 terminal can be measured in the ACV gear of the digital multimeter 26. The output signal of the function generator 24 directly measured by the digital multimeter 26 is the input signal voltage value of the "signal source output" 9 terminal, and the calibration of the parameter "nominal dB (100Hz)" is completed.

[0030] When calibrating the attenuator:

[0031] Connect the output port of function generator 24 to the "signal source output" 9 port of the calibrated standard voltage / charge converter 1, and connect the "amplifier (out) / calibration capacitor" 4 interface to the voltage input terminal of digital multimeter 26 through a BNC cable. Set function generator 24 to square wave, 100Hz, 5Vrms, high impedance state, output signal, press the "0dB" 10 switch, and measure the current voltage value in the ACV range of digital multimeter 26. Press the "-10dB" 11, "-20dB" 12, "-30dB" 13, and "-40dB" 14 switches respectively to measure the voltage value at each attenuation value, and calculate the measured attenuation value by formula 20*log(V2 / V1) with the measured value at "0dB" 10. Change the frequency of function generator 24 and measure the attenuation values ​​of other frequencies according to the above steps to complete the calibration of parameter "attenuator".

[0032] When calibrating the filter:

[0033] The output port of the function generator 24 is connected to the "signal source output" port 9 of the calibrated standard voltage / charge converter 1, and the function generator 24 is set to square wave, 100Hz, 5Vrms, high impedance state, and output signal. The "voltmeter input / amplifier (in)" port 4 is connected to the digital multimeter voltage 26 input end to measure the voltage of the "connect to voltmeter input" terminal 8, and the "amplifier (out) / calibration capacitor" port 4 is connected to the digital multimeter 26 voltage input end to measure the voltage of the "amplifier (out) / calibration capacitor" terminal 4. The "0dB" 10 and "calibration amplifier" 2 buttons are in the pressed state; the attenuation value is calculated by the formula 20log(V2 / V1), and the output frequency of the function generator 24 is changed to measure the voltage of the "connect to voltmeter input" terminal 8 and the "amplifier (out) / calibration capacitor" terminal 4 at each frequency, and the attenuation value is calculated to complete the calibration of the parameter "filter".

[0034] When calibrating the capacitor:

[0035] Disconnect the power supply of the calibrated standard voltage / charge converter 1, and directly measure the capacitance of the calibration standard voltage / charge converter 1 with the capacitance tester 25. The cores of the "amplifier (out) / calibration capacitance" 4 and "charge amplifier input" 5 interfaces are respectively connected to the H and L ends of the capacitance tester, and the ground wire is connected to the shell ground wire of the capacitance tester 25. Press "calibration capacitance" 3 for the calibration standard voltage / charge converter 1, and set the capacitance tester 25 to 1kHz, 1V; press "10pF" 19, "100pF" 20, "1nF" 21, "10nF" 22, "0.1μF" 23 keys respectively, and measure the values ​​of each nominal capacitance respectively, completing the calibration of the parameter "capacitance".

[0036] The standard voltage / charge converter calibration device provided by the present invention can effectively calibrate different parameters of the standard voltage / charge converter through a function generator, a digital multimeter and a capacitance tester. The calibration device is convenient and quick to assemble, has high device stability, small measurement uncertainty, and the measurement result is consistent with the theoretical calculated value. The operation is simple and can be achieved by using a general function generator, a digital multimeter and a capacitance tester, thus saving hardware costs, effectively solving the problem of standard voltage / charge converter value traceability, and having high practicality.

[0037] As an implementable embodiment, when calibrating the standard voltage of a standard voltage / charge converter, the amplifier (out) / calibration capacitor interface of the standard voltage / charge converter is connected to the voltage input terminal of a digital multimeter, the digital multimeter is in DCV test mode, the calibration amplifier switch of the standard voltage / charge converter is in a triggered state, the input and output switch is in the left position, triggering the ground, +1V, and -1V buttons to complete the corresponding nominal voltage calibration.

[0038] Through the special connection relationship between the digital voltmeter and the standard voltage / charge converter and the switch triggering method, the calibration of the nominal voltage of the standard voltage / charge converter is effectively realized, the calibration operation is convenient, and the result is more accurate.

[0039] As an implementable embodiment, when calibrating the nominal DB (100Hz) of the standard voltage / charge converter, the function trigger output terminal is connected to the signal source output port of the standard voltage / charge converter, the voltmeter input / amplifier (in) is connected to the voltage input terminal of the digital multimeter, the calibration amplifier of the standard voltage / charge converter is triggered, the input and output switch is in the left position, the AC switch is in the trigger state, the function generator outputs an excitation signal, and the output signal of the function generator measured by the ACV gear of the digital multimeter is the voltage value of the output terminal of the signal source of the standard voltage / charge converter.

[0040] Through the special connection relationship between the function trigger and the digital multimeter and the standard voltage / charge converter, as well as the switch triggering method, the voltage value of the output terminal of the standard voltage / charge converter signal source is effectively calibrated.

[0041] As an implementable method, when calibrating the attenuator of a standard voltage / charge converter, the voltage input terminal of a digital multimeter is connected to the amplifier (out) / calibration capacitor interface of the standard voltage / charge converter, and the function generator is connected to the signal source output of the standard voltage / charge converter. The function generator provides an excitation signal for the standard voltage / charge converter. The digital multimeter measures the attenuation voltage values ​​of the standard voltage / charge converter in the 0dB, -10dB, -20dB, -30dB, and -40dB switch trigger states at different frequencies, and calculates the attenuation value.

[0042] Through the special connection relationship between the digital multimeter, the function generator and the standard voltage / charge converter, as well as the switch trigger, the calibration of the standard voltage / charge converter attenuator is effectively achieved, and the calibration is more accurate and direct.

[0043] As an implementable method, when calibrating the filter of a standard voltage / charge converter, the output port of the function generator is connected to the signal source output of the standard voltage / charge converter and outputs an excitation signal. The voltage input terminal of the digital multimeter is connected to the voltmeter input / amplifier (in) and amplifier (out) / calibration capacitor of the standard voltage / charge converter. The voltages at the voltmeter input terminal and the amplifier (out) / calibration capacitor terminal are detected respectively. The 0dB of the standard voltage / charge converter and the calibration amplifier are triggered, the attenuation value is calculated, and the voltages at the voltmeter input terminal and the amplifier (out) / calibration capacitor terminal are measured to calculate the attenuation value.

[0044] Through the connection relationship between the function generator, the digital multimeter and the standard voltage / charge converter, as well as the signal switch triggering method, the filter calibration is effectively realized. The calibration method is more accurate and intuitive, and the accuracy rate is higher.

[0045] As an implementable embodiment, when calibrating the capacitance of a standard voltage / charge converter, the standard voltage / charge converter is in a power-off state, the H terminal, L terminal and ground wire of the capacitance tester are respectively connected to the amplifier (out) / calibration capacitance, charge amplifier input and ground of the standard voltage / charge converter, the capacitance tester is grounded, and the calibration capacitance switch of the standard voltage / charge converter is triggered. By triggering the 10pF, 100pF, 1nF, 10nF, and 0.1μF keys of the standard voltage / charge converter, the nominal capacitance values ​​are measured.

[0046] Through the special connection relationship between the capacitance tester and the standard voltage / charge converter, the measurement of each nominal capacitance value of the standard voltage / charge converter is effectively achieved, and the measurement result is more accurate.

[0047] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0048] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A standard voltage / charge converter calibration device, comprising a standard voltage / charge converter, characterized in that: Also included are a function generator, a digital multimeter, and a capacitance tester; The function generator is connected to the signal input terminal of the standard voltage / charge converter to provide an excitation signal for the standard voltage / charge converter; the digital multimeter is connected to the DC amplifier module and the attenuator module of the standard voltage / charge converter to calibrate the DC amplifier and the attenuator; the capacitance tester is connected to the test capacitor module of the standard voltage / charge converter to calibrate the capacitor; in, When calibrating the capacitance of the standard voltage / charge converter, the standard voltage / charge converter is in a power-off state, the H terminal, L terminal and ground wire of the capacitance tester are respectively connected to the amplifier / calibration capacitance, charge amplifier input and ground of the standard voltage / charge converter, the capacitance tester is grounded, and the calibration capacitance switch of the standard voltage / charge converter is triggered. By triggering the 10pF, 100pF, 1nF, 10nF, and 0.1μF keys of the standard voltage / charge converter, the measured values ​​of each nominal capacitance value are measured.

2. The standard voltage / charge converter calibration device according to claim 1, characterized in that: When calibrating the standard voltage of the standard voltage / charge converter, the amplifier / calibration capacitance interface of the standard voltage / charge converter is connected to the voltage input terminal of the digital multimeter, the digital multimeter is in DCV test mode, the calibration amplifier switch of the standard voltage / charge converter is in a triggered state, the input and output switch is in the left position, triggering the ground, +1V, and -1V buttons to complete the corresponding nominal voltage calibration.

3. The standard voltage / charge converter calibration device according to claim 1, characterized in that: When calibrating the nominal DB of the standard voltage / charge converter, the function trigger output is connected to the signal source output port of the standard voltage / charge converter, the voltmeter input / amplifier is connected to the voltage input of the digital multimeter, the calibration amplifier of the standard voltage / charge converter is triggered, the input and output switches are in the left position, the AC switch is in the trigger state, the function generator outputs an excitation signal, and the output signal of the function generator measured by the ACV gear of the digital multimeter is the voltage value of the signal source output of the standard voltage / charge converter.

4. The standard voltage / charge converter calibration device according to claim 1, characterized in that: When calibrating the attenuator of the standard voltage / charge converter, the voltage input terminal of the digital multimeter is connected to the amplifier / calibration capacitor interface of the standard voltage / charge converter, the function generator is connected to the signal source output of the standard voltage / charge converter, the function generator provides an excitation signal for the standard voltage / charge converter, and the digital multimeter measures the attenuation voltage values ​​of the standard voltage / charge converter in the 0dB, -10dB, -20dB, -30dB, and -40dB switch triggering states at different frequencies, and calculates the attenuation value.

5. The standard voltage / charge converter calibration device according to claim 1, characterized in that: When calibrating the filter of the standard voltage / charge converter, the output port of the function generator is connected to the signal source output of the standard voltage / charge converter and outputs an excitation signal. The voltage input terminal of the digital multimeter is connected to the voltmeter input / amplifier and amplifier / calibration capacitor of the standard voltage / charge converter. The voltages connected to the voltmeter input terminal and the amplifier / calibration capacitor terminal are detected respectively. The 0dB and calibration amplifier of the standard voltage / charge converter are triggered, the attenuation value is calculated, and the voltages connected to the voltmeter input terminal and the amplifier / calibration capacitor terminal are measured to calculate the attenuation value.

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