Method for calibrating a pressure determination process in a vacuum interrupter and for determining the pressure in a measuring vacuum interrupter
Patent Information
- Application Number
- PCT/EP2026/052309
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-28
- Filing Date
- 2026-01-29
- Publication Date
- 2026-09-03
Smart Images
Figure EP2026052309_03092026_PF_FP_ABST
Abstract
Description
[0001] 2024PF00130
[0002] Method for calibrating a pressure measurement in a vacuum switching tube and for determining a pressure in a measuring vacuum switching tube
[0003] The invention relates to a method for calibrating a pressure determination in a vacuum switching tube and for determining a pressure in a measuring vacuum switching tube.
[0004] A vacuum interrupter is designed to perform electrical switching operations under a vacuum. To interrupt an electric current, the two electrodes in the vacuum interrupter are moved from a contact state, in which the two electrodes are in contact, to a spaced state, in which the two electrodes are separated. In the spaced state, the vacuum electrically isolates the two electrodes from each other. To ensure the vacuum interrupter functions correctly, the vacuum pressure must be low. Conventionally, the vacuum pressure is determined using the magnetron method. In this method, electrons are accelerated in an electric field and forced by a magnetic field onto spiral paths, so that the electrons have to travel a significantly longer path to the anode.Gas molecules struck by these electrons can be ionized, allowing a gas discharge to build up in the vacuum. The current of the gas discharge correlates with the vacuum pressure. To deduce the vacuum pressure from the current, a calibration is required in which a variety of known pressures are set in the vacuum switching tube, a gas discharge is generated at each pressure, and the current of the gas discharge is measured. However, this is disadvantageously complex.
[0005] The object of the invention is therefore to provide a method for calibrating a pressure measurement in a vacuum switching tube and a method for determining a pressure in a 2024PF00130
[0006] 2
[0007] to create measuring vacuum switching tubes that are easy to implement.
[0008] The inventive method for calibrating a pressure measurement in a vacuum switching tube comprises the steps of: a) providing a calibration device with a vacuum switching tube having a first electrode and a second electrode, which have a contact state in which the first electrode and the second electrode are in contact with each other, and a separation state in which the first electrode and the second electrode are separated from each other, as well as a housing that defines an interior space in which the first electrode and the second electrode are arranged and which is configured to maintain a vacuum in the interior space so that, in the separation state, the first electrode and the second electrode can be electrically isolated from each other by the vacuum, a vacuum system comprising a tube and a pressure sensor by means of which the pressure in the tube can be measured, wherein the vacuum switching tube has a through-hole,that connects the interior to the pipe via a fluid-conducting connection; b) Applying a magnetic field and an electric field to the interior so that a gas discharge is generated in the interior, wherein the magnetic field in the interior has an orientation different from the electric field; c) Measuring a time-resolved current of the gas discharge and simultaneously measuring a time-resolved pressure in the pipe using the pressure sensor; d) Determining a time offset between the onset of an increase in the time-resolved current and the onset of a decrease in the time-resolved pressure; e) Correcting the offset by shifting the time-resolved current and / or the time-resolved pressure in time; f) Assigning a plurality of currents occurring after a maximum of the time-resolved current to the simultaneously arranged pressure, thereby forming a calibration function. 2024PF00130
[0009] 3
[0010] The invention is based on the understanding that in a gas discharge, gas particles in the vacuum are ionized and subsequently removed from the interior by the electric field. This reduces the vacuum pressure.
[0011] According to the invention, in step f), a plurality of value pairs are determined from the current and the pressure, wherein each of the value pairs can form a support point of the calibration function. This allows several of the value pairs to be determined by means of a single measurement, thereby making it easier to determine the calibration function than in a conventional method in which only a single value pair can be determined in each gas discharge.
[0012] The through-hole and the pipe preferably have an inner cross-section of at least 1 cm at their narrowest point. 2This is . This allows the pressure to be transferred particularly quickly from the interior to the pipe, which means that a change in pressure can be measured particularly quickly by the pressure sensor.
[0013] It is preferred that the through-hole is provided in the housing. Alternatively, it is preferred that the through-hole is provided in the first electrode.
[0014] The vacuum system preferably includes a pump configured to evacuate the interior via the pipe. This allows any desired vacuum pressure to be set before step b). It is preferred that the vacuum system includes a shut-off device located in a flow path extending from the pressure sensor to the pump, which keeps the flow path closed during step c). This prevents gas from entering the interior via the pipe during step c). Gas ingress would distort the calibration curve. 2024PF00130
[0015] 4
[0016] The inventive method for determining a pressure in a measuring vacuum switching tube comprises the steps: g) Providing the measuring vacuum switching tube, which has a first electrode and a second electrode, which has a
[0017] a contact state in which the first electrode and the second electrode are in contact with each other, and a separation state in which the first electrode and the second electrode are separated from each other, and a housing that delimits an interior space in which the first electrode and the second electrode are arranged, and that maintains a vacuum in the interior space so that in the separation state the first electrode and the second electrode are electrically isolated from each other by the vacuum; h) providing the calibration function; i) applying a magnetic field and an electric field to the interior space of the measuring vacuum switching tube so that a measuring gas discharge is generated in the interior space of the measuring vacuum switching tube, wherein the magnetic field in the interior space has an orientation different from the electric field; j) measuring a time-resolved current of the measuring gas discharge and determining a maximum of the time-resolved current of the measuring gas discharge;k) Determining the pressure of the vacuum of the measuring vacuum switching tube based on the maximum of the time-resolved current of the measuring gas discharge and based on the calibration function .;
[0018] It is preferred that the interior of the vacuum switching tube is identical in construction to the interior of the measuring vacuum switching tube, except for the presence of the through-hole. This allows the vacuum pressure of the measuring vacuum switching tube to be determined with high accuracy. The walls that delimit the interior of the vacuum switching tube preferably have the same material(s) as the walls that delimit the interior of the measuring vacuum switching tube. This allows the vacuum pressure of the measuring vacuum switching tube to be determined with particularly high accuracy. 2024PF00130
[0019] The invention will be explained in more detail below with reference to the attached schematic drawings. These show
[0020] Figure 1 shows a section through a vacuum switching tube,
[0021] Figure 2 shows a section through a calibration device,
[0022] Figure 3 shows an example of a time-resolved current and an example of a time-resolved pressure and
[0023] Figure 4 shows an example calibration curve.
[0024] With reference to Figures 1 to 4, a method for calibrating a pressure reading in a vacuum switching tube 1 comprises the steps of: a) providing a calibration device 52, which includes a vacuum switching tube 1 and a vacuum system 40. The calibration device 52 has a first electrode 3 and a second electrode 4, which have a contact state in which the first electrode 3 and the second electrode 4 are in contact with each other, and a spaced-away state in which the first electrode 3 and the second electrode 4 are spaced apart from each other. Furthermore, the vacuum switching tube 1 has a housing 2, which defines an interior space 26 in which the first electrode 3 and the second electrode 4 are arranged. The housing 2 is configured to maintain a vacuum in the interior space 26, so that in the spaced-away state the first electrode 3 and the second electrode 4 can be electrically isolated from each other by the vacuum.The vacuum system 40 has a tube 41 and a pressure sensor 42 by means of which the pressure p in the tube 41 can be measured. The vacuum switching tube 1 has a through-hole 27 that connects the interior 26 to the tube 41 in a fluid-conducting manner; b) Applying a magnetic field 24 and an electric field 23 to the interior 26 (see Figure 1) so that a gas discharge is generated in the interior 26, wherein the magnetic field 24 in the interior 26 has an orientation that differs from the orientation of the electric field 23; c) Measuring a 2024PF00130.
[0025] d) Determining a time-resolved current I(t) of the gas discharge and simultaneously measuring a time-resolved pressure p(t) in the tube 41 using the pressure sensor 42 (see Figure 3); d) Determining a time offset At between the start ti of an increase in the time-resolved current I(t) and the start t2 of a decrease in the time-resolved pressure p(t); e) Correcting the offset At by shifting the time-resolved current I(t) and / or the time-resolved pressure p(t); f) Assigning a plurality of values according to a time-resolved maximum I ma x of the time-resolved current I(t) corresponding to the simultaneously arranged pressure p, thereby forming a calibration function 55 (see Figure 4). The through-hole 27 and the tube 41 can have an internal cross-section at their narrowest point of at least 1 cm². 2Figure 2 shows that in one example the through-hole 27 can be provided in the housing 2. In another example, the through-hole 27 can be provided in the first electrode 3.
[0026] Figure 1 shows that the vacuum switching tube 1 provided in step a) can have an axial direction 31, a radial direction 32 related to the axial direction 31, and a circumferential direction 33 related to the axial direction 31. The first electrode 3 can be fixed relative to the housing 2, and the second electrode 4 can be longitudinally displaceable in the axial direction 31 relative to the housing 2. For this purpose, the vacuum switching tube 1 can have a bearing 9 on which the second electrode 4 can slide in and against the axial direction 31. It is conceivable to displace the second electrode 4 mechanically, in particular by using a spring mechanism. Starting from the contact state shown in Figures 1 and 2, the first electrode 3 and the second electrode 4 can be brought into a spaced-away state by displacing the second electrode 4 away from the first electrode 4 in the axial direction 31.The first electrode 3 can have a first contact surface 7 and the second electrode 4 can 2024PF00130.
[0027] The electrodes have a second contact surface 8, wherein the first contact surface 7 and the second contact surface 8 are arranged in the interior 26. The first electrode 3 can be formed with a thickening at its longitudinal end facing the second electrode 4, and the second electrode 4 can also be formed with a thickening at its longitudinal end facing the first electrode 3. The first contact surface 7 and the second contact surface 8 are in contact in the contact state, allowing a current to flow from the first electrode 3 to the second electrode 4, and are spaced apart from each other in the separation state, preventing the current from flowing from the first electrode 3 to the second electrode 4.
[0028] The first electrode 3 can have a first terminal 5 located outside the housing 2, and the second electrode 4 can have a second terminal 6 located outside the housing 2. Electrical conductors can be connected to the first terminal 5 and the second terminal 6 in an electrically conductive manner. The vacuum switching tube 1 can have a bellows 10 which is attached to the bearing 9 and to the first electrode 3, in particular to an electrode projection 25 extending radially 32 from the remaining first electrode 3, enclosing the first electrode 3 and sealing the interior 26 against a vacuum.
[0029] As can be seen from Figures 1 and 2, the housing 2 can be formed from several sub-housings. The housing 2 can, for example, have a switching chamber housing 14, which is made of or consists of a metal or alloy. The switching chamber housing 14 can completely enclose a switching chamber 13 in the circumferential direction 33, which is part of the interior 26. The first contact surface 7 and the second contact surface 8 are arranged in the switching chamber 13.
[0030] The housing 2 can, for example, comprise a first ceramic housing 17 arranged opposite the axial direction 31 of the switching chamber housing 14, and / or a second ceramic housing 18 arranged in the axial direction 31 of the switching chamber housing 14. The switching chamber housing 14 can be electrically isolated from other components of the vacuum switching tube 1 by means of the first ceramic housing 17 and / or the second ceramic housing 18. It is conceivable that the first ceramic housing 17 and / or the second ceramic housing 18 are formed in one piece or are formed from a plurality of partial ceramic housings 19 arranged side by side in the axial direction 31.
[0031] The housing 2 can, for example, comprise a first flange housing 15, arranged opposite the axial direction 31 to the first ceramic housing 17 and attached to the first electrode 3, and a second flange housing 16, arranged in the axial direction 31 to the second ceramic housing 18 and attached to the bearing 19. The first flange housing 15 and the first ceramic housing 17 can fully delimit a first flange chamber 11 in the circumferential direction 33, which is part of the interior 26. The second flange housing 16 and the second ceramic housing 18 can fully delimit a second flange chamber 12 in the circumferential direction 33, which is part of the interior 26. The first flange chamber 11 and the second flange chamber 12 can have a smaller cross-section than the switching chamber 13, with the cross-section having a normal parallel to the axial direction 31.
[0032] The vacuum switching tube 1 can have two chamber shields 20 attached to the switching chamber housing 14 and projecting into the interior 26, one of the two chamber shields 20 electrically shielding the first flange chamber 11 from the switching chamber 13 and against metal vapor, and the other of the two chamber shields 20 electrically shielding the second flange chamber 12 from the switching chamber 13 and against metal vapor. The chamber shields 20 can be electrically conductive.
[0033] to be connected to the switching chamber housing 14. Furthermore, for electrical shielding and shielding against metal vapor, a flange shield 21 can be attached to the first flange housing 15, which projects into the interior 26, and another flange shield 21 can be attached to the second flange housing 16, which also projects into the interior 26. In the area where the partial ceramic housings 19 abut each other, an intermediate shield 22 can be arranged for electrical shielding and shielding against metal vapor, with the intermediate shield 22 projecting into the interior 26.
[0034] Figure 1 shows that the electric field 23 applied in step b) can extend from the first electrode 3 and / or the second electrode 4 to the housing 2. Both polarities are conceivable, i.e., the anode can be formed by the housing 2 as well as by the first electrode 3 and / or the second electrode 4. The first electrode 3 and the second electrode 4 can be in contact or separated state. In particular, the electric field 23 can extend to the switching chamber housing 14. The electric field 23 and the magnetic field 24 can enclose an angle in the interior 26, which lies, for example, in the range of 70° to 90°, in particular 80° to 90° or 85° to 90°. The electric field 23 can, for example, enclose an angle with the radial direction 32 which lies in a range of 0° to 30°, in particular in a range of 0° to 15° or of 0° to 5°.The magnetic field 24 can, for example, enclose an angle with the axial direction 31 which lies in a range of 0° to 30°, in particular in a range of 0° to 15° or from 0° to 5°, cf. Figure 1.
[0035] Alternatively, instead of the electric field 23 applied in step b) extending from the first electrode 3 and / or the second electrode 4 to the housing 2, the first electrode 3 and the second electrode 4 can be arranged in the spaced-away state and the electric field 2024PF00130
[0036] 10
[0037] The electric field 23 can extend from the first electrode 3 to the second electrode 4. Both polarities are conceivable, i.e., the anode can be formed by the first electrode 3 or the second electrode 4. The electric field 23 and the magnetic field 24 can form an angle within the interior 26, for example, in a range of 70° to 90°, in particular 80° to 90° or 85° to 90°. The electric field 23 can, for example, form an angle with the axial direction 31, in a range of 0° to 30°, in particular 0° to 15° or 0° to 5°. The magnetic field 24 can, for example, enclose an angle with the radial direction 32 which lies in a range of 0° to 30°, in particular in a range of 0° to 15° or of 0° to 5°.
[0038] Figure 2 shows that the calibration device 52 can have a voltage source 53 configured to generate the electric field 23. The calibration device 52 can also have a magnet 54 configured to generate the magnetic field 24. The magnet 54 can be, for example, a permanent magnet and / or a coil. It is conceivable that the magnetic field 24 is switched on first, followed by the electric field 23.
[0039] Alternatively, it is conceivable that the electric field 23 and the magnetic field 24 are switched on simultaneously. The calibration device 52 can include an ammeter 56 configured to measure the current I of the gas discharge.
[0040] Figure 2 shows that the pressure sensor 42 can be arranged outside the condensing switching tube 1. It is conceivable that the pressure sensor 42 uses a different measuring principle than the magnetron method to determine the pressure p. Alternatively, it is conceivable that the pressure sensor 42 is based on the magnetron method and that the pressure sensor 42 is used for this purpose.
[0041] 11
[0042] The first electrode has 3 different electrodes and the second electrode has 4 different electrodes.
[0043] As can be seen from Figure 1, the vacuum system 40 can include a pump configured to evacuate the interior 26 via the pipe 41. Furthermore, the vacuum system 40 can include a shut-off device 44 located in a flow path extending from the pressure sensor 42 to the pump, the shut-off device 44 keeping the flow path closed while step c) is performed. The pump can be a turbomolecular pump 47. The vacuum system 40 can also include a diaphragm pump 48.
[0044] The interior space 26 is connected to the pipe 41 in a fluid-conducting manner, in particular by means of a flange connection.
[0045] For example, the pipe 41 can have a first flange 49, and the vacuum switching tube 1 can have a second flange 50 that completely encloses the through-hole 27. The first flange 49 and the second flange 50 can form the flange connection. A flange gasket 51 can be provided between the first flange 49 and the second flange 50, contacting both the first flange 49 and the second flange 50 and thus sealing the through-hole 27 and the pipe 41 to the outside. For example, the flange gasket 51 can be made of or consist of an epoxy resin, or it can be made of or consist of a Viton O-ring.
[0046] The vacuum system 40 can include an additional pressure sensor 43 configured to determine the pressure in a flow path extending from the shut-off device 44 to the pump. This additional pressure sensor 43 can be based on a different measuring principle than the magnetron method. The vacuum system 40 can include a gas reservoir 46 containing a gas that can flow into the interior 26 via the pipe 41. The vacuum system 2024PF00130
[0047] 12
[0048] 40 can have a further shut-off device 45, via which the gas reservoir 46 can be opened and closed.
[0049] Figure 3 shows a graph plotting current I and pressure p against time p. It illustrates an example of time-resolved current I(t) and pressure p(t). The time-resolved current I(t) is characterized by a steep initial rise in current I, with a maximum I ma x is reached and then falls less steeply. The pressure profile p(t) is characterized by the fact that at times earlier than the onset ti of the rise in the time-resolved current I(t), the pressure p is essentially constant. It is conceivable that a pressure p is established before the onset of the gas discharge (i.e., before ti), which lies within a range of IO. -9 mbar up to 10 -3The pressure p before the onset of the gas discharge can be set, for example, using the pump and / or the gas reservoir 46. The time interval after the start ti of the increase in the time-resolved current I(t) is the start t2 of the decrease in the time-resolved pressure p(t). The delay At is therefore calculated according to At = t2 - ti.
[0050] It is conceivable to smooth the time-resolved current I(t), in particular by means of a low-pass filter. The low-pass filter can, for example, have a cutoff frequency in the range of 1 Hz to 500 Hz, in particular from 1 Hz to 20 Hz. It is additionally or alternatively conceivable to adjust the time-resolved current I(t), at least in a temporal sub-range, with a matching function in order to smooth the time-resolved current I(t). Similarly, it is conceivable to smooth the time-resolved pressure p(t), in particular by means of a low-pass filter and / or by fitting with a matching function. The low-pass filter can, for example, have a cutoff frequency in the range of 1 Hz to 500 Hz, in particular from 1 Hz to 20 Hz. Additionally or alternatively, it is conceivable to smooth a plurality of the 2024PF00130
[0051] 13
[0052] to measure time-resolved currents I (t) and a majority of time-resolved pressures p (t) and then to average the majority of time-resolved currents I (t) and the majority of time-resolved pressures p (t).
[0053] To correct the offset in step e), it is conceivable, for example, to shift the time-resolved current profile I (t) and / or the time-resolved pressure p (t) in time so that the beginning ti of the increase of the time-resolved current I (t) and the beginning t2 of the decrease of the time-resolved pressure p (t) are simultaneous.
[0054] For example, it is conceivable that the time-resolved current I (t) is shifted by At or that the time-resolved pressure p (t) is shifted by -At.
[0055] Several methods are conceivable for determining the start ti of the increase in the time-resolved current I(t) and the start t2 of the decrease in the time-resolved pressure p(t). For example, the start ti of the increase in the time-resolved current I(t) can be determined as the time at which the current I first exceeds a threshold current. Similarly, the start t2 of the decrease in the time-resolved pressure p(t) can be determined as the time at which the pressure first falls below a threshold value.
[0056] From the time-resolved current I(t) and the time-resolved pressure p(t), in which, after step e), the beginning ti of the increase in the time-resolved current I(t) and the beginning t2 of the decrease in the time-resolved pressure p(t) are simultaneous, a plurality of value pairs can be determined. These pairs are formed by a current I and a pressure p that occur simultaneously. The calibration function 55 can be created from these value pairs (see Figure 4). Figure 4 shows a plot of pressure p against current I, in which the value pairs can be entered. These value pairs can, for example, serve as support points for the calibration function 55. The calibration function 552024PF00130
[0057] 14
[0058] may be in the form of a lookup table and / or in the form of an adjustment function (as shown in Figure 4).
[0059] A method for determining a pressure in a measuring vacuum switching tube 30 comprises the steps: g) Providing the measuring vacuum switching tube 30, which has a first electrode 3 and a second electrode 4, which has a
[0060] a contact state in which the first electrode 3 and the second electrode 4 are in contact with each other, and a separation state in which the first electrode 3 and the second electrode 4 are separated from each other, and a housing 2 which defines an interior space 26 in which the first electrode 3 and the second electrode 4 are arranged, and which maintains a vacuum in the interior space 26, such that in the separation state the first electrode 3 and the second electrode 4 are electrically isolated from each other by the vacuum; h) providing the calibration function 55; i) applying a magnetic field 24 and an electric field 23 to the interior space 26 of the measuring vacuum switching tube 30, such that a measuring gas discharge is generated in the interior space 26 of the measuring vacuum switching tube 30, wherein the magnetic field 24 in the interior space 26 has an orientation different from the electric field 23;j) Measuring a time-resolved current I (t) of the measuring gas discharge and determining a maximum I; max the time-resolved current I (t) of the measuring gas discharge; k) Determining the pressure p of the vacuum of the measuring vacuum switching tube 30 based on the maximum I max the time-resolved current I(t) of the measuring gas discharge and based on the calibration function 55. The interior 26 of the vacuum switching tube 1 can be identical in construction to the interior 26 of the measuring vacuum switching tube 30, except for the presence of the through-hole 27. The walls that delimit the interior 26 of the vacuum switching tube 1 can be made of the same material or materials as the walls that delimit the interior 26 of the measuring vacuum switching tube 1. 2024PF00130
[0061] 15
[0062] Reference symbol list
[0063] 1 vacuum switching tube
[0064] 2 cases
[0065] 3 first electrode
[0066] 4 second electrode
[0067] 5 first connection
[0068] 6 second connection
[0069] 7 first contact surface
[0070] 8 second contact surface
[0071] 9 warehouses
[0072] 10 bellows
[0073] 11 First flange chamber 12 Second flange chamber 13 Switching chamber
[0074] 14 Switch chamber housing 15 First flange housing 16 Second flange housing 17 First ceramic housing 18 Second ceramic housing 19 Partial ceramic housing
[0075] 20-chamber screen
[0076] 21 Flange screen
[0077] 22 Intermediate screen
[0078] 23 electric field
[0079] 24 Magnetic field
[0080] 25 Electrode protrusion 26 Interior
[0081] 27 Through hole
[0082] 30 Measuring vacuum switching tube 31 Axial direction
[0083] 32 Radial direction
[0084] 33 Circumferential direction
[0085] 40 vacuum system
[0086] 41 pipe
[0087] 42 Pressure sensor
[0088] 43 Additional pressure sensor 44 Shut-off device 2024PF00130
[0089] 16
[0090] 45 additional shut-off device
[0091] 46 Gas reservoir
[0092] 47 Turbomolecular pump
[0093] 48 Diaphragm pump
[0094] 49 first flange
[0095] 50 second flange
[0096] 51 Flange gasket
[0097] 52 Calibration device
[0098] 53 Voltage source
[0099] 54 Magnet
[0100] 55 Calibration function
[0101] 56 ammeters
[0102] I electric current
[0103] p print
[0104] t time
[0105] I (t) time-resolved current
[0106] p(t) time-resolved pressure
[0107] ti Beginning of an increase in the time-resolved current I (t) t2 Beginning of a decrease in the time-resolved pressure p (t) At offset
[0108] Imax Maximum of I (t)
Claims
2024PF00130 17 Patent claims 1. Method for calibrating a pressure measurement in a vacuum switching tube ( 1 ) , comprising the steps : a) Providing a calibration device (52) with a vacuum switching tube (1) comprising a first electrode (3) and a second electrode (4) having a contact state in which the first electrode (3) and the second electrode (4) are in contact with each other, and a separation state in which the first electrode (3) and the second electrode (4) are separated from each other, and a housing (2) comprising an interior space (26) in which the first electrode (3) and the second electrode (4) are arranged, and which is configured to maintain a vacuum in the interior space (26) so that in the separation state the first electrode (3) and the second electrode (4) can be electrically isolated from each other by the vacuum, a vacuum system (40) comprising a tube (41) and a pressure sensor ( 42) has, by means of which the pressure (p) in the pipe (41) can be measured,wherein the vacuum switching tube ( 1 ) has a through-hole ( 27 ) which connects the interior ( 26 ) fluid-conductingly to the tube ( 41 ); b) Applying a magnetic field ( 24 ) and an electric field ( 23 ) to the interior ( 26 ) such that a gas discharge is generated in the interior ( 26 ), wherein the magnetic field ( 24 ) in the interior ( 26 ) has an orientation different from the electric field ( 23 ); c) Measuring a time-resolved current (I(t)) of the gas discharge and simultaneously measuring a time-resolved pressure (p(t)) in the tube (41) using the pressure sensor (42); d) Determining a time offset (At) between the start (ti) of an increase in the time-resolved current (I(t)) and the start (t2) of a decrease in the time-resolved pressure (p(t)); e) Correcting the offset (At) by shifting the time-resolved current (I(t)) and / or the time-resolved pressure (p(t)); 2024PF00130 18 f) Assigning a plurality of temporally according to a maximum ( I ma x) the time-resolved current ( I (t) ) currents ( I ) to the pressure (p) arranged at the same time , thereby forming a calibration function (55).
2. Method according to claim 1, wherein the through hole (27) and the tube (41) have an inner cross-section at their narrowest point of at least 1 cm². 2 amounts .
3. Method according to claim 1 or 2, wherein the through-hole (27 ) is provided in the housing (2 ).
4. Method according to claim 1 or 2, wherein the through hole (27 ) is provided in the first electrode (3 ).
5. Method according to any one of claims 1 to 4, wherein the vacuum system (40) comprises a pump configured to evacuate the interior (26) via the tube (41).
6. Method according to claim 5, wherein the vacuum system (40) has a shut-off device (44) which is arranged in a flow path extending from the pressure sensor (42) to the pump and by means of which the flow path is kept closed while step c) is carried out.
7. Method for determining a pressure in a measuring vacuum switching tube (30) , comprising the steps: g) Providing the measuring vacuum switching tube (30) which has a first electrode (3) and a second electrode (4) which has a contact state in which the first electrode (3) and the second electrode (4) are in contact with each other, and a spaced-away state in which the first electrode (3) and the second electrode (4) are spaced apart from each other, and a housing (2) which defines an interior space (26) in which the first electrode (3) and the second electrode (4) are arranged, and which is located in the interior space (26)2024PF00130 19 a vacuum is maintained, so that in the separation state the first electrode (3) and the second electrode (4) are electrically isolated from each other by the vacuum; h) Providing a calibration function (55) according to any one of claims 1 to 6; i) Applying a magnetic field (24 ) and an electric field (23) to the interior (26) of the measuring vacuum switching tube (30) such that a measuring gas discharge is generated in the interior (26) of the measuring vacuum switching tube (30), wherein the magnetic field (24 ) in the interior (26) has an orientation different from the electric field (23); j) Measuring a time-resolved current (I(t)) of the measuring gas discharge and determining a maximum (I ma x) of the time-resolved current (I(t)) of the measuring gas discharge; k) Determining the pressure (p) of the vacuum of the measuring vacuum switching tube (30) based on the maximum (Imax) of the time-resolved current (I(t)) of the measuring gas discharge and based on the calibration function (55) .
8. Method according to claim 7, wherein the interior (26) of the vacuum switching tube (1) is identical in construction to the interior (26) of the measuring vacuum switching tube (30) except for the presence of the through-hole (27).
9. Method according to claim 8, wherein the walls that define the interior (26) of the vacuum switching tube (1) are made of the same material or materials as the walls that define the interior (26) of the measuring vacuum switching tube (1).