Ion flow measuring method and measuring circuit for extremely high thermal cathode ionization gauge

Abstract

The invention discloses an ion flow measurement method and a measurement circuit for an extremely-high thermal cathode ionization gauge, and relates to the technical field of ion flow measurement, and the method comprises the steps: obtaining a demand range of ion flow measurement, and dividing the demand range into a first ion flow range and a second ion flow range; the ion flow measurement in the first ion flow range is completed through a preset first measurement mode, and the ion flow measurement in the second ion flow range is completed through a preset second measurement mode; measurement of electron currents of different measurement sections is achieved through the measurement circuit arranged based on the measurement method, the problem that in high vacuum measurement, a traditional ion current measurement circuit is poor in precision in ultrahigh measurement is solved, and the blank in ultrahigh vacuum measurement is filled.

Description

Technical Field

[0001] This invention relates to the field of ion current measurement technology, and more specifically, to a method and circuit for measuring ion current using an extremely high-thermal-cathode ionization gauge. Background Technology

[0002] In the measurement circuit of a thermionic cathode ionization gauge, ion current measurement is a real-time reflection of the vacuum level. The accuracy and stability of the vacuum, as well as the accuracy and stability of the measurement circuit, are crucial. In high vacuum measurements, ion current measurement circuits are mostly high-impedance amplifiers, but in ultra-high vacuum measurements, high-impedance amplifiers are somewhat inadequate. Therefore, it is necessary to provide an ion current measurement method in an ultra-high vacuum thermionic cathode ionization gauge. Summary of the Invention

[0003] The purpose of this invention is to provide an ion current measurement method and measurement circuit for an ultra-high thermal cathode ionization gauge, so as to solve the problem that conventional ion current measurement circuits currently have poor accuracy and stability in ultra-high measurements.

[0004] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0005] In a first aspect, this application provides a method for measuring ion current using an extremely high-temperature cathode ionization gauge, comprising the following specific steps:

[0006] The required range for ion current measurement is obtained, and the required range is divided into a first ion current range and a second ion current range.

[0007] Ion current measurements within the first ion current range are performed using a preset first measurement method, while ion current measurements within the second ion current range are performed using a preset second measurement method.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, the range of the aforementioned first ion current is 1.6 × 10⁻⁶. -6 A-1.6×10 -12 A; The second ion current range is 1.6 × 10⁻⁶. -12 A-1.6×10 -15 A.

[0010] Furthermore, the first measurement method is a high-impedance amplification method, and the second measurement method is an integral amplification method.

[0011] In a second aspect, this application provides an ion current measurement circuit for an ultra-high thermal cathode ionization gauge, used to implement an ion current measurement method for an ultra-high thermal cathode ionization gauge according to any one of the first aspects, including operational amplifiers U2, U3A, analog switch chip U4, voltage reference chip U6, operational amplifier U8, reed relays RELAY1, RELAY2, and RELAY3 connected together.

[0012] Furthermore, the aforementioned reed relay RELAY1 is connected to a resistor R1, a capacitor C1, and a diode D1, wherein:

[0013] Resistor R1 and capacitor C1 are connected in parallel. One end of the parallel connection is connected to pin 2 of reed relay RELAY1, and the other end is connected to reed relay RELAY2. The output of diode D1 is connected to pin 3 of reed relay RELAY1.

[0014] The reed relay RELAY3 is connected to a resistor R3, a capacitor C9, and a diode D3, wherein:

[0015] Resistor R3 and capacitor C9 are connected in parallel. One end of the parallel connection is connected to pin 2 of reed relay RELAY3, and the other end is connected to the other end of resistor R1 and capacitor C1 connected in parallel. The output of diode D3 is connected to pin 3 of reed relay RELAY3.

[0016] Furthermore, the aforementioned reed relay RELAY2 is connected to diode D2, capacitor C11, resistor R4, resistor R6, and resistor R7, wherein:

[0017] The output of diode D2 is connected to pin 3 of reed relay RELAY2. Pins 1 of reed relay RELAY1, pin 1 of reed relay RELAY2, and pin 1 of reed relay RELAY3 are interconnected. Pin 1 of reed relay RELAY2 is also connected to one end of resistor R4. The other end of resistor R4 is connected to the other end of the parallel connection of resistor R1 and capacitor C1, and one end of resistor R7. The other end of resistor R7 is connected to one end of resistor R6 and pin 8 of analog switch chip U4. The other end of resistor R6 is connected to one end of capacitor C11, pin 2 of reed relay RELAY2, and pin 2 of analog switch chip U4.

[0018] Furthermore, the aforementioned operational amplifier U2 is connected to resistor R9, polarized capacitor C13, capacitor C14, capacitor C16, diode D5, and diode D6, wherein:

[0019] Pin 6 of operational amplifier U2 is connected to one end of resistor R9, the input terminal of diode D6, and one end of capacitor C16. The other end of resistor R9 is connected to the other end of capacitor C11. The output terminal of diode D6 is connected to the output terminal of diode D5. The input terminal of diode D5 and the other end of capacitor C16 are connected to pin 3 of operational amplifier U3A.

[0020] Pin 2 of operational amplifier U2 is connected to pin 1 of analog switch chip U4. Pin 7 of operational amplifier U2 is connected in sequence to one end of capacitor C14, the positive terminal of polarized capacitor C13, and pin 6 of voltage reference chip U6. Pin 4 of operational amplifier U2 is connected in sequence to the other end of capacitor C14, the negative terminal of polarized capacitor C13, and pin 4 of voltage reference chip U6. Pin 2 of voltage reference chip U6 is connected to one end of capacitor C20, and the other end of capacitor C20 is grounded.

[0021] Furthermore, the aforementioned operational amplifier U3A is connected to resistors R14, R21, R28, R29, R33, capacitors C22, C23, and C27, wherein:

[0022] The first pin of operational amplifier U3A is connected to the junction of resistors R6 and R7. The first pin of operational amplifier U3A is also connected in sequence to one end of resistor R21, one end of resistor R28, and one end of resistor R33. The other end of resistor R33 is connected to one end of capacitor C27; the other end of resistor R21 is connected to one end of capacitor C23.

[0023] Pin 2 of operational amplifier U3A is connected to the other end of capacitor C23, the other end of resistor R28, and one end of resistor R29, respectively; pin 4 of operational amplifier U3A is connected to one end of capacitor C22, and the other end of capacitor C22 and the other end of resistor R29 are grounded.

[0024] Furthermore, the aforementioned operational amplifier U8 is connected to resistor R31, capacitor C26, capacitor C32, resistor R36, resistor R24, resistor R32, capacitor C24, capacitor C25, resistor R34, capacitor C33, capacitor C28, and diode D8, wherein:

[0025] Pins 2 and 6 of operational amplifier U8 are connected to the two ends of capacitor C24, respectively. Pin 2 of operational amplifier U8 is also connected to one end of resistor R32. The other end of resistor R32 is connected to one end of resistor R24, one end of capacitor C26 and one end of resistor R31, respectively. The other end of resistor R31 is connected to pin 1 of operational amplifier U3A.

[0026] Pin 3 of operational amplifier U8 is connected to one end of resistor R36 and one end of capacitor C32, while the other ends of resistor R36 and capacitor C32 are grounded.

[0027] Pin 4 of operational amplifier U8 is connected to one end of capacitor C33, and the other end of capacitor C33 is grounded.

[0028] Pin 6 of operational amplifier U8 is also connected to one end of resistor R34. The other end of resistor R34 is connected to the other end of resistor R24, the output of diode D8, and one end of capacitor C28. The input of diode D8 and the other end of capacitor C28 are grounded.

[0029] Pin 7 of operational amplifier U8 is connected to one end of capacitor C25, and the other end of capacitor C25 is grounded.

[0030] Furthermore, the aforementioned ion current measurement circuit also includes a temperature sensor U1, which is connected to a resistor R2 and a capacitor C7, wherein:

[0031] The second pin of the temperature sensor U1 is connected to one end of the resistor R2 and one end of the capacitor C7. The other end of the resistor R2 is connected to the positive terminal of the power supply, and the other end of the capacitor C7 is grounded.

[0032] Thirdly, this application provides an electronic device, including: at least one processor, at least one memory, and a data bus;

[0033] In this system, the processor and memory communicate with each other via a data bus; the memory stores program instructions that can be executed by the processor, and the processor calls the program instructions to execute the method as described in any of the first aspects.

[0034] Fourthly, this application provides a non-transitory computer-readable storage medium that stores computer instructions that cause a computer to perform any of the methods in the first aspect.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] In this application, the measurement range is divided into two measurement segments. The first ion current range, which is the conventional range, is used to measure the electron current through a high-impedance amplification method. In the other range of ultra-high vacuum measurement, the electron current is measured through an integral amplification method. The measurement circuit based on the measurement method is used to measure the electron current in different measurement segments, which solves the problem of poor accuracy of traditional ion current measurement circuits in ultra-high vacuum measurement and fills the gap in ultra-high vacuum measurement. Attached Figure Description

[0037] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0038] Figure 1 This is a partial connection diagram of the measurement circuit in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of another part of the measurement circuit in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of another part of the measurement circuit in an embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram of another part of the measurement circuit in an embodiment of the present invention;

[0042] Figure 5 This is a flowchart of the measurement method in an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0045] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0046] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, they are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0047] Furthermore, the use of terms such as "horizontal," "vertical," and "sag" does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0048] In the description of the embodiments of the present invention, "multiple" means at least two.

[0049] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0050] Example 1: To address the issue of poor accuracy of traditional ion current measurement circuits in ultra-high vacuum measurements and to fill the gap in extremely high vacuum measurements, this example provides an ion current measurement method using an extremely high thermionic cathode ionization gauge, such as... Figure 5 As shown, the specific steps include the following:

[0051] S1, obtain the required range for ion current measurement, and divide the required range into a first ion current range and a second ion current range.

[0052] The first ion current ranges from 1.6 × 10⁻⁶. -6 A-1.6×10 -12 A; The second ion current range is 1.6 × 10⁻⁶. -12 A-1.6×10 -15 A.

[0053] S2, the ion current measurement within the first ion current range is completed by a preset first measurement method, and the ion current measurement within the second ion current range is completed by a preset second measurement method.

[0054] The first measurement method is a high-impedance amplification method, and the second measurement method is an integral amplification method.

[0055] Example 2: This application provides an ion current measurement circuit for an extremely high thermal cathode ionization gauge, used to implement the ion current measurement method for an extremely high thermal cathode ionization gauge in Example 1, such as... Figures 1-4 As shown, the measurement circuit includes components that are connected in the following ways:

[0056] Operational amplifier U2, operational amplifier U3A, analog switch chip U4, voltage reference chip U6, operational amplifier U8, reed relay RELAY1, reed relay RELAY2, and reed relay RELAY3.

[0057] In the above, the reed relay RELAY1 is connected to a resistor R1, a capacitor C1, and a diode D1, as follows: Figure 1 As shown, where:

[0058] Resistor R1 and capacitor C1 are connected in parallel. One end of the parallel connection is connected to pin 2 of reed relay RELAY1, and the other end is connected to reed relay RELAY2. The output of diode D1 is connected to pin 3 of reed relay RELAY1.

[0059] In the above, the reed relay RELAY3 is connected to a resistor R3, a capacitor C9, and a diode D3, as follows: Figure 1 As shown, where:

[0060] Resistor R3 and capacitor C9 are connected in parallel. One end of the parallel connection is connected to pin 2 of reed relay RELAY3, and the other end is connected to the other end of resistor R1 and capacitor C1 connected in parallel. The output of diode D3 is connected to pin 3 of reed relay RELAY3.

[0061] In the above, the reed relay RELAY2 is connected to diode D2, capacitor C11, resistor R4, resistor R6, and resistor R7, as follows: Figure 2 As shown, where:

[0062] The output of diode D2 is connected to pin 3 of reed relay RELAY2. Pins 1 of reed relay RELAY1, pin 1 of reed relay RELAY2, and pin 1 of reed relay RELAY3 are interconnected. Pin 1 of reed relay RELAY2 is also connected to one end of resistor R4. The other end of resistor R4 is connected to the other end of the parallel connection of resistor R1 and capacitor C1, and one end of resistor R7. The other end of resistor R7 is connected to one end of resistor R6 and pin 8 of analog switch chip U4. The other end of resistor R6 is connected to one end of capacitor C11, pin 2 of reed relay RELAY2, and pin 2 of analog switch chip U4.

[0063] In the above, operational amplifier U2 is connected to resistor R9, polarized capacitor C13, capacitor C14, capacitor C16, diode D5, and diode D6, as follows: Figure 2 As shown, where:

[0064] Pin 6 of operational amplifier U2 is connected to one end of resistor R9, the input terminal of diode D6, and one end of capacitor C16. The other end of resistor R9 is connected to the other end of capacitor C11. The output terminal of diode D6 is connected to the output terminal of diode D5. The input terminal of diode D5 and the other end of capacitor C16 are connected to pin 3 of operational amplifier U3A.

[0065] Pin 2 of operational amplifier U2 is connected to pin 1 of analog switch chip U4. Pin 7 of operational amplifier U2 is connected in sequence to one end of capacitor C14, the positive terminal of polarized capacitor C13, and pin 6 of voltage reference chip U6. Pin 4 of operational amplifier U2 is connected in sequence to the other end of capacitor C14, the negative terminal of polarized capacitor C13, and pin 4 of voltage reference chip U6. Pin 2 of voltage reference chip U6 is connected to one end of capacitor C20, and the other end of capacitor C20 is grounded.

[0066] In the above description, operational amplifier U3A is connected to resistors R14, R21, R28, R29, R33, capacitors C22, C23, and C27, as follows: Figure 3 As shown, where:

[0067] The first pin of operational amplifier U3A is connected to the junction of resistors R6 and R7. The first pin of operational amplifier U3A is also connected in sequence to one end of resistor R21, one end of resistor R28, and one end of resistor R33. The other end of resistor R33 is connected to one end of capacitor C27; the other end of resistor R21 is connected to one end of capacitor C23.

[0068] Pin 2 of operational amplifier U3A is connected to the other end of capacitor C23, the other end of resistor R28, and one end of resistor R29, respectively; pin 4 of operational amplifier U3A is connected to one end of capacitor C22, and the other end of capacitor C22 and the other end of resistor R29 are grounded.

[0069] In the above, operational amplifier U8 is connected to resistor R31, capacitor C26, capacitor C32, resistor R36, resistor R24, resistor R32, capacitor C24, capacitor C25, resistor R34, capacitor C33, capacitor C28, and diode D8, as follows. Figure 4 As shown, where:

[0070] Pins 2 and 6 of operational amplifier U8 are connected to the two ends of capacitor C24, respectively. Pin 2 of operational amplifier U8 is also connected to one end of resistor R32. The other end of resistor R32 is connected to one end of resistor R24, one end of capacitor C26 and one end of resistor R31, respectively. The other end of resistor R31 is connected to pin 1 of operational amplifier U3A.

[0071] Pin 3 of operational amplifier U8 is connected to one end of resistor R36 and one end of capacitor C32, while the other ends of resistor R36 and capacitor C32 are grounded.

[0072] Pin 4 of operational amplifier U8 is connected to one end of capacitor C33, and the other end of capacitor C33 is grounded.

[0073] Pin 6 of operational amplifier U8 is also connected to one end of resistor R34. The other end of resistor R34 is connected to the other end of resistor R24, the output of diode D8, and one end of capacitor C28. The input of diode D8 and the other end of capacitor C28 are grounded.

[0074] Pin 7 of operational amplifier U8 is connected to one end of capacitor C25, and the other end of capacitor C25 is grounded.

[0075] The aforementioned ion current measurement circuit also includes a temperature sensor U1, which is connected to a resistor R2 and a capacitor C7, wherein:

[0076] The second pin of the temperature sensor U1 is connected to one end of the resistor R2 and one end of the capacitor C7. The other end of the resistor R2 is connected to the positive terminal of the power supply, and the other end of the capacitor C7 is grounded.

[0077] Specifically, through Figures 1-4 The various circuits in the circuit constitute the overall measurement circuit in this embodiment. Figures 1-4 The connections in the diagram are made using labels; that is, those with the same label are connected. For example: Figure 1 The "1" in the text is related to... Figure 2 The "1" in the first part connects the others, and so on, which will not be repeated here; see also Figures 1-4 In the diagram, U3A is an operational amplifier for increasing slew rate. Its voltage will suddenly increase during signal transitions. The LMC6041 has a slew rate of 0.02V / s, while the TL062 has a slew rate of 3.5V / µs, meeting the requirements for voltage surge. D5 and D6 are Zener diodes, providing a 3V voltage limit. U8, R31, R24, C26, and C26 form a second-order filter circuit. U6 (MAX6176) is a reference source chip with a 10V reference voltage and a 6-pin output, providing power to U2.

[0078] The entire circuit is divided into two measurement segments: for values ​​greater than 160 FA, high-impedance amplification is used; for values ​​less than 160 FA, integrating amplification is employed. The high-impedance amplification is achieved at 1.6 nA (1.6 × 10⁻⁶). -9 A) to 1.6pA (1.6×10 -12 A), using a high-resistivity method, less than 1.6 pA (1.6 × 10⁻⁶). -12 A) Using integral amplification; in Figure 2In the diagram, U2: The minimum offset current of the LMC6041 is ±2FA. In this circuit, it is used as a current-to-voltage converter: the formula is: U = R × I; where U is the op-amp output voltage; I is the ion current; R is the op-amp voltage; the resistance on the feedback arm of U2 is divided into 3 levels, switched by a reed relay; combined with... Figures 1-4 :

[0079] When the input ion current is between 1.6 μA and 160 nA (1.6 × 10⁻⁶), -7 A-1.6×10 -6 A) When reed relays RELAY1 and RELAY2 are working and in the closed state, resistor R1 is active, and the range of U is 0.4-0.04V.

[0080] When the ion current is between 160 nA and 1.6 nA (1.6 × 10⁻⁶), -9 A-1.6×10 -7 A) Reed relays RELAY3 and RELAY2 are working, while reed relay RELAY1 is off. At this time, resistor R3 is active, and the voltage U varies from 0.8 to 0.008V.

[0081] When the ion current is between 1.6 nA and 16 PA (1.6 × 10⁻⁶), -11 A-1.6×10 -9 A) Reed relays RELAY3, RELAY2, and RELAY1 are disconnected; at this time, resistor R3 is active, and the range of U is 0.8 to 0.008V.

[0082] When the ion current is between 16 pA and 160 FA (1.6 × 10⁻⁶), -13 A-1.6×10 -11 A) Reed relays RELAY3, RELAY2, and RELAY1 are disconnected; at this time, resistor R3 is active, and the range of U is 0.8 to 0.008V.

[0083] When using integral amplification, the integral amplification formula is: In the formula, I C For capacitor current, ΔV C Let Δt be the voltage change across the capacitor, Δt be the time change (the time interval corresponding to the voltage change), and C be the capacitance value. The voltage output is: U = I×T / C, where U represents the output voltage (the final output voltage value of the integrating amplifier circuit), I represents the input current (the current signal input to the integrating amplifier circuit), T represents the integration time (the duration of the integration operation on the input current), and C represents the capacitance value.

[0084] Among them, such as Figure 2 As shown, U4 is an analog switch controlled by a microcontroller on pin 6. When pin 6 is at ground level (0), pins 1-2 are on, and pins 1-8 are off. When pin 6 is high, pins 1-2 are off, and pins 1-8 are on. This allows control of the input ion current at 1.6 × 10⁻⁶. -15 A-1.6×10 -12 When A is working, the integration time is set to 3 seconds, at which point the integrating capacitor C11 is involved; where...

[0085] When the output voltage is 160FA: U=(160×10 -15 ×3) / 4×10 -12 =0.12 volts;

[0086] At the minimum ion current of 1.6 FA: U = 0.0012 V.

[0087] The above-mentioned measurement circuit has high measurement accuracy and can obtain FA-level current very stably. In ultra-high vacuum measurement, it adds strength to the domestic substitution and fills the gap in ultra-high vacuum measurement.

[0088] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0089] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0090] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0091] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0092] Those skilled in the art will understand that all or part of the steps in the above facts and methods can be implemented by a program instructing related hardware. The program or the program described therein can be stored in a computer-readable storage medium. When the program is executed, it includes the following steps: at this time, the corresponding method steps are introduced. The storage medium can be ROM / RAM, magnetic disk, optical disk, etc.

[0093] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for measuring ion current using an extremely high-temperature cathode ionization gauge, characterized in that, The specific steps include the following: Obtain the required range for ion current measurement, and divide the required range into a first ion current range and a second ion current range; Ion current measurements within the first ion current range are performed using a preset first measurement method, while ion current measurements within the second ion current range are performed using a preset second measurement method.

2. The method for measuring ion current using an ultra-high thermal cathode ionization gauge according to claim 1, characterized in that, The first ion current range is 1.6 × 10⁻⁶. -6 A-1.6×10 -12 A; The second ion current range is 1.6 × 10⁻⁶. -12 A-1.6×10 - 15 A.

3. The method for measuring ion current using an ultra-high thermal cathode ionization gauge according to claim 1, characterized in that, The first measurement method is a high-impedance amplification method, and the second measurement method is an integral amplification method.

4. An ion current measurement circuit for an ultra-high thermal cathode ionization gauge, used to implement the ion current measurement method for an ultra-high thermal cathode ionization gauge according to any one of claims 1-3, characterized in that, This includes operational amplifiers U2, U3A, analog switch chip U4, voltage reference chip U6, operational amplifier U8, reed relays RELAY1, RELAY2, and RELAY3, which are interconnected.

5. The ion current measurement circuit of an ultra-high thermal cathode ionization gauge according to claim 4, characterized in that, The reed relay RELAY1 is connected to a resistor R1, a capacitor C1, and a diode D1, wherein: The resistor R1 and the capacitor C1 are connected in parallel. One end of the parallel connection is connected to the second pin of the reed relay RELAY1, and the other end is connected to the reed relay RELAY2. The output of the diode D1 is connected to the third pin of the reed relay RELAY1. The reed relay RELAY3 is connected to a resistor R3, a capacitor C9, and a diode D3, wherein: The resistor R3 and the capacitor C9 are connected in parallel. One end of the parallel connection is connected to the second pin of the reed relay RELAY3, and the other end is connected to the other end of the parallel connection of the resistor R1 and the capacitor C1. The output of the diode D3 is connected to the third pin of the reed relay RELAY3.

6. The ion current measurement circuit of an ultra-high thermal cathode ionization gauge according to claim 5, characterized in that, The reed relay RELAY2 is connected to diode D2, capacitor C11, resistor R4, resistor R6, and resistor R7, wherein: The output terminal of diode D2 is connected to pin 3 of reed relay RELAY2. Pins 1 of reed relay RELAY1, pin 1 of reed relay RELAY2, and pin 1 of reed relay RELAY3 are interconnected. Pin 1 of reed relay RELAY2 is also connected to one end of resistor R4. The other end of resistor R4 is connected to the other end of the parallel connection of resistor R1 and capacitor C1, and one end of resistor R7. The other end of resistor R7 is connected to one end of resistor R6 and pin 8 of analog switch chip U4. The other end of resistor R6 is connected to one end of capacitor C11, pin 2 of reed relay RELAY2, and pin 2 of analog switch chip U4.

7. The ion current measurement circuit of an ultra-high thermal cathode ionization gauge according to claim 6, characterized in that, The operational amplifier U2 is connected to a resistor R9, a polarized capacitor C13, a capacitor C14, a capacitor C16, a diode D5, and a diode D6, wherein: The 6th pin of the operational amplifier U2 is connected to one end of the resistor R9, the input terminal of the diode D6, and one end of the capacitor C16. The other end of the resistor R9 is connected to the other end of the capacitor C11. The output terminal of the diode D6 is connected to the output terminal of the diode D5. The input terminal of the diode D5 and the other end of the capacitor C16 are connected to the 3rd pin of the operational amplifier U3A. The second pin of the operational amplifier U2 is connected to the first pin of the analog switch chip U4. The seventh pin of the operational amplifier U2 is connected in sequence to one end of the capacitor C14, the positive terminal of the polarized capacitor C13, and the sixth pin of the voltage reference chip U6. The fourth pin of the operational amplifier U2 is connected in sequence to the other end of the capacitor C14, the negative terminal of the polarized capacitor C13, and the fourth pin of the voltage reference chip U6. The second pin of the voltage reference chip U6 is connected to one end of the capacitor C20, and the other end of the capacitor C20 is grounded.

8. The ion current measurement circuit of an ultra-high thermal cathode ionization gauge according to claim 7, characterized in that, The operational amplifier U3A is connected to resistors R14, R21, R28, R29, R33, capacitors C22, C23, and C27, wherein: The first pin of the operational amplifier U3A is connected to the junction of the resistors R6 and R7. The first pin of the operational amplifier U3A is also connected in sequence to one end of the resistor R21, one end of the resistor R28, and one end of the resistor R33. The other end of the resistor R33 is connected to one end of the capacitor C27. The other end of the resistor R21 is connected to one end of the capacitor C23. The second pin of the operational amplifier U3A is connected to the other end of the capacitor C23, the other end of the resistor R28, and one end of the resistor R29, respectively; the fourth pin of the operational amplifier U3A is connected to one end of the capacitor C22, and the other end of the capacitor C22 and the other end of the resistor R29 are grounded.

9. The ion current measurement circuit of an ultra-high thermal cathode ionization gauge according to claim 8, characterized in that, The operational amplifier U8 is connected to resistor R31, capacitor C26, capacitor C32, resistor R36, resistor R24, resistor R32, capacitor C24, capacitor C25, resistor R34, capacitor C33, capacitor C28, and diode D8, wherein: The second and sixth pins of the operational amplifier U8 are respectively connected to the two ends of the capacitor C24. The second pin of the operational amplifier U8 is also connected to one end of the resistor R32. The other end of the resistor R32 is connected to one end of the resistor R24, one end of the capacitor C26 and one end of the resistor R31. The other end of the resistor R31 is connected to the first pin of the operational amplifier U3A. The third pin of the operational amplifier U8 is connected to one end of the resistor R36 and one end of the capacitor C32, respectively, and the other end of the resistor R36 and the other end of the capacitor C32 are grounded. The fourth pin of the operational amplifier U8 is connected to one end of the capacitor C33, and the other end of the capacitor C33 is grounded. The 6th pin of the operational amplifier U8 is also connected to one end of the resistor R34. The other end of the resistor R34 is connected to the other end of the resistor R24, the output terminal of the diode D8, and one end of the capacitor C28. The input terminal of the diode D8 and the other end of the capacitor C28 are grounded. The 7th pin of the operational amplifier U8 is connected to one end of the capacitor C25, and the other end of the capacitor C25 is grounded.

10. The ion current measurement circuit of an ultra-high thermal cathode ionization gauge according to claim 8, characterized in that, The ion current measurement circuit also includes a temperature sensor U1, which is connected to a resistor R2 and a capacitor C7, wherein: The second pin of the temperature sensor U1 is connected to one end of resistor R2 and one end of capacitor C7, respectively. The other end of resistor R2 is connected to the positive terminal of the power supply, and the other end of capacitor C7 is grounded.

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