A high-precision temperature test system for optical fiber ring and its use method

Abstract

The invention discloses a temperature testing system for a high-precision optical fiber ring and a method for using the same. The system comprises an optical fiber ring testing device arranged in a temperature box, and an optical path signal processing device, a circuit signal processing device and a data acquisition and processing device arranged outside the temperature box; the optical fiber ring testing device comprises a lower cover, a lower gasket, an upper gasket, an upper cover, a Y-waveguide optical integrator and a temperature sensor; the optical path signal processing device comprises an optical fiber coupler, a light source and a detector; the circuit signal processing device comprises a temperature sensor power supply module, a temperature sensor temperature signal acquisition module, an optical fiber ring signal processing module and a data transmission module; the data acquisition and processing device comprises a data acquisition module, a data storage module and a data processing module; the system can meet the needs of various temperature environments and can shield electromagnetic interference, and reflects the influence of the thermal design of the optical fiber gyroscope shell itself on the temperature performance of the high-precision optical fiber ring, and the method for using the system is simple and easy to implement, and the optical fiber ring is not easily damaged.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature testing of optical fiber rings of optical fiber gyroscopes, and in particular to a temperature testing system for high-precision optical fiber rings and a method for using the system. Background Art

[0002] The high-precision fiber ring is the core component of the high-precision fiber gyroscope, and its accuracy directly determines the final accuracy of the high-precision fiber gyroscope. In actual use, any interference to the high-precision fiber ring will cause the non-reciprocity of the forward and reverse transmission light in the high-precision fiber ring, causing the high-precision fiber gyroscope to produce bias drift and reduce the accuracy of the high-precision fiber gyroscope.

[0003] The main interferences to high-precision fiber optic rings include: ambient temperature interference, ambient magnetic field interference and vibration interference. Among them, ambient temperature has the most obvious impact on the measurement accuracy of high-precision fiber optic gyroscopes. In order to ensure the full temperature accuracy of high-precision fiber optic gyroscopes and improve the qualified rate of high-precision fiber optic gyroscopes, it is an important link in the production of high-precision fiber optic rings to conduct temperature test evaluation on high-precision fiber optic rings and obtain the temperature index of high-precision fiber optic rings before assembling high-precision fiber optic gyroscopes. Regarding the temperature test of the fiber optic ring of a fiber optic gyroscope, the published patent CN100538309C discloses an online modular test device for the fiber optic ring in a fiber optic gyroscope, and the published patent CN111964659A discloses a temperature test and evaluation system for the fiber optic ring of a fiber optic gyroscope. Although these prior arts provide solutions and standards for the temperature test of the fiber optic ring of a fiber optic gyroscope, they are limited to the solution of the temperature test of the fiber optic ring of a fiber optic gyroscope, and do not mention a device for the temperature test of a high-precision fiber optic ring, resulting in the inability to implement a specific high-precision fiber optic ring temperature test. At the same time, these prior arts do not consider the effect of shielding the environmental magnetic field and vibration on the high-precision fiber optic ring. When directly applied to the temperature test and evaluation of the high-precision fiber optic ring, the effect of the magnetic field and vibration on the high-precision fiber optic ring will be brought into the temperature test and evaluation of the high-precision fiber optic ring, thereby causing a deviation in the temperature test and evaluation of the high-precision fiber optic ring. Therefore, it is necessary to design a device for the temperature test of the high-precision fiber optic ring.

[0004] Based on the above description, as the core component of the high-precision fiber ring temperature test, the high-precision fiber ring temperature test system needs to meet the following requirements in terms of structural design:

[0005] 1) The test system can meet the settings of various temperature environment simulations to achieve consistency with actual usage conditions. At the same time, the test system should also be able to reflect the impact of the thermal design of the fiber optic gyroscope housing itself on the temperature performance of the high-precision fiber optic ring;

[0006] 2) The structural design for fixing the high-precision optical fiber ring in the test system should be easy to install and disassemble, and the impact of the shielding magnetic field and the vibration during the test on the high-precision optical fiber ring should be considered to avoid damage to the high-precision optical fiber ring during use;

[0007] 3) The test system should consider the smooth routing when the high-precision fiber ring pigtail is connected to the test module to avoid pigtail breakage. Summary of the invention

[0008] The object of the present invention is to provide a high-precision fiber optic ring temperature testing system that meets various requirements for the device in the fiber optic gyroscope fiber optic ring temperature test.

[0009] Another object of the present invention is to provide a method for using the high-precision fiber optic ring temperature testing system to implement temperature testing of a fiber optic gyroscope fiber optic ring.

[0010] To this end, the technical solution of the present invention is as follows:

[0011] A high-precision temperature test system for an optical fiber ring, comprising an optical fiber ring test device arranged in a temperature box, and an optical path signal processing device, a circuit signal processing device and a data acquisition and processing device arranged outside the temperature box;

[0012] The optical fiber ring testing device comprises a lower cover, a lower gasket, an upper gasket and an upper cover which are arranged in sequence from bottom to top, as well as a Y-waveguide optical integrator and a temperature sensor; an open cylinder is arranged at the top of the lower cover, a circular upper cover mounting groove is arranged at the center of the cylinder, and an annular optical fiber ring mounting groove is formed in the circumference; the upper cover is composed of a lower cylindrical body, an annular cylindrical body extending axially upward from the edge of the top surface of the lower cylindrical body, and an upper annular plate whose inner edge is fixed to the top of the annular cylindrical body, so that when the lower cylindrical body of the upper cover is inserted into the upper cover mounting groove of the lower cover, the upper annular plate cover is installed at the top opening of the optical fiber ring mounting groove, so that the optical fiber ring mounting groove forms a closed annular space; the lower gasket and the upper The gaskets are two annular gaskets with the same structure and size, and the two are built into the optical fiber ring installation groove; the Y-waveguide optical integrator includes a Y-waveguide optical integrator body embedded in the upper cover, on which are provided a first pigtail input terminal for connecting to the first pigtail of the optical fiber ring under test, a second pigtail input terminal connected to the second pigtail of the optical fiber ring under test, and an optical signal output terminal; the temperature sensor includes a temperature sensor body embedded in the upper cover, on which are provided a power ground input terminal connected to a power ground input electrical signal line, a power input terminal connected to a power input electrical signal line, and a temperature signal output terminal connected to a temperature signal output electrical signal line;

[0013] The optical path signal processing device is connected to the optical signal output terminal to input the optical signal provided by the light source to the Y-waveguide optical integrator, and receive the optical signal of two beams of light transmitted in opposite directions in the optical fiber ring under test fed back by the Y-waveguide optical integrator;

[0014] The circuit signal processing device is respectively connected to the power ground input electrical signal line, the power +V input electrical signal line and the temperature signal output electrical signal line to supply power to the temperature sensor and collect the temperature signal. At the same time, the circuit signal processing device is connected to the optical path signal processing device to collect the optical signal output by the optical path signal processing device and convert it into an electrical signal.

[0015] The data acquisition and processing device is connected to the circuit signal processing device to acquire, store and process the output optical signal and temperature signal to obtain the temperature characteristic index of the measured optical fiber ring.

[0016] The optical path signal processing device includes a fiber optic coupler, a light source and a detector; one end of the fiber optic coupler is connected to the optical signal output terminal in the fiber optic ring test device through an optical signal transmission optical fiber, and the other end is connected to the light source and the detector respectively through an optical signal transmission optical fiber.

[0017] Furthermore, the circuit signal processing device includes a temperature sensor power supply module, a temperature sensor temperature signal acquisition module, an optical fiber ring signal processing module and a data transmission module; the negative pole and the positive pole of the temperature sensor power supply module are respectively connected to the power ground input electrical signal line and the other end of the power input electrical signal line to power the temperature sensor; the temperature sensor temperature signal acquisition module is connected to the temperature signal output electrical signal line of the temperature sensor to collect the temperature signal from the temperature sensor; the optical fiber ring signal processing module is connected to the detector through the optical signal output electrical signal line to collect the optical signal output by the optical fiber ring and convert it into an electrical signal; the data transmission module is respectively connected to the temperature sensor temperature signal acquisition module and the optical fiber ring signal processing module through the signal transmission line to output the optical signal and temperature signal converted into electrical signals to the outside.

[0018] Furthermore, the data acquisition and processing device includes a data acquisition module, a data storage module and a data processing module; the data acquisition module is connected to the data transmission module through a signal transmission line to receive the optical signal and temperature signal converted into electrical signals; the data storage module is connected to the data acquisition module through a signal transmission line to store the optical signal and temperature signal converted into electrical signals on a storage medium; the data processing module is connected to the data storage module through a signal transmission line to process the optical signal and temperature signal converted into electrical signals and obtain the temperature characteristic index of the optical fiber ring under test.

[0019] Furthermore, an outer annular convex strip and an inner annular convex strip are respectively provided at the outer edge and inner edge of the top surface of the upper annular plate of the upper cover, so that an annular pigtail groove is formed therebetween, and a pigtail outlet notch I connected with the optical fiber ring mounting groove is provided on the outer annular convex strip, a pigtail outlet notch II is provided on the inner annular convex strip which is farthest from the pigtail outlet notch I, and a first narrow pigtail fixing groove and a second narrow pigtail fixing groove connected with the upper cover mounting groove are respectively provided on both sides of the pigtail outlet notch II; a fiber outlet notch is provided on the upper gasket located below the pigtail outlet notch.

[0020] Furthermore, two cylindrical bosses are symmetrically arranged at the bottom of the upper cover mounting groove of the upper cover, and a threaded blind hole is opened axially downward from the top surface of each cylindrical boss to screw in a screw as a handle of the upper cover.

[0021] Furthermore, the sizes of the upper gasket and the lower gasket are adapted to the sizes of the optical fiber ring mounting groove, and the thicknesses of the upper gasket and the lower gasket satisfy the following conditions: when the lower gasket, the optical fiber ring to be measured and the upper gasket are stacked in sequence from bottom to top, the thickness of the whole is slightly greater than the distance from the bottom of the optical fiber ring mounting groove to the bottom surface of the upper annular plate of the upper cover, so that the optical fiber ring to be measured can be pressed and fixed in the optical fiber ring mounting groove; the outer diameter of the optical fiber ring to be measured is slightly smaller than the outer diameters of the upper gasket and the lower gasket; and the inner diameters of the upper gasket and the lower gasket are both slightly smaller than the inner diameter of the optical fiber ring to be measured.

[0022] Furthermore, three cylindrical bosses are evenly distributed along the circumferential direction on the bottom surface of the lower cover, and a threaded blind hole is opened axially upward from the bottom surface of each cylindrical boss, so that the optical fiber ring test device can be fixed on the mounting plate of the temperature box and leave a wiring space between the lower cover and the mounting plate; an arc-shaped through hole is opened from the upper cover to penetrate the upper cover and the lower cover.

[0023] Furthermore, the upper cover and the lower cover are both made of magnetic shielding material 1J79, and are subjected to high-temperature vacuum annealing after processing to improve magnetic permeability; the upper gasket and the lower gasket are annular gaskets made of silicone rubber.

[0024] A method for using the high-precision optical fiber ring temperature test system to perform temperature testing, the steps are as follows:

[0025] S1. Assemble the fiber ring test device:

[0026] Place the lower gasket, the optical fiber ring to be tested and the upper gasket into the optical fiber ring installation groove of the lower cover in sequence, and then install and fix the upper cover so that the lower cover, the lower gasket, the optical fiber ring to be tested, the upper gasket and the upper cover are coaxially arranged and fixed as a whole; fix the Y-waveguide optical integrator and the temperature sensor on the upper cover;

[0027] S2. Fusing the lines of the Y-waveguide optical integrator, including:

[0028] The first pigtail of the optical fiber ring to be tested is led out through the fiber outlet notch of the upper gasket and the pigtail outlet notch I of the upper cover in sequence, and then runs along the left side of the annular pigtail groove opened in the upper cover until it passes through the pigtail outlet notch II and enters the first narrow pigtail groove entrance and is fixed in the first narrow pigtail groove, and the end of the first pigtail extends into the circular groove of the upper cover and is connected to the first pigtail input terminal of the Y-waveguide optical integrator;

[0029] The second pigtail of the optical fiber ring to be tested is led out through the fiber outlet notch of the upper gasket and the pigtail outlet notch I of the upper cover in sequence, and then runs along the right side of the annular pigtail groove opened in the upper cover until it passes through the pigtail outlet notch II and enters the entrance of the second narrow pigtail groove and is fixed in the second narrow pigtail groove, and the end of the second pigtail extends into the circular groove of the upper cover and is connected to the second pigtail input terminal of the Y-waveguide optical integrator;

[0030] One end of the optical signal transmission fiber is fused to the optical signal output terminal of the Y-waveguide optical integrator, and the other end of the optical signal transmission fiber is fused to the single pigtail end of the optical fiber coupler of the optical path signal processing device;

[0031] S3. Solder the circuit of the temperature sensor:

[0032] The power ground input electric signal line is welded to the power ground input terminal, the power input electric signal line is welded to the power input terminal, and the temperature signal output electric signal line is welded to the temperature signal output terminal; then the power ground input electric signal line, the power input electric signal line and the temperature signal output electric signal line are parallelly passed through the circular through hole opened on the circular groove of the upper cover and the arc-shaped through hole opened on the upper cover mounting groove of the lower cover to reach the space formed by the support of the three cylindrical bosses of the lower cover, and then connected to the external circuit signal processing device;

[0033] S4. Perform temperature test on the optical fiber ring under test;

[0034] The optical fiber ring test device is fixed in a temperature box; the optical signal transmission optical fiber, the power ground input electrical signal line, the power input electrical signal line and the temperature signal output electrical signal line are passed through the wire holes provided on the temperature box, and then, the optical signal transmission optical fiber is fused with the optical fiber coupler, the power ground input electrical signal line and the power input electrical signal line are respectively welded and connected with the negative electrode and the positive electrode of the temperature sensor power supply module, and the temperature signal output electrical signal line is welded and connected with the temperature signal acquisition module of the temperature sensor; then, the temperature of the temperature box is set according to the temperature setting requirements of the temperature test, and during the test, the sensitive angular velocity signal fed back by the tested optical fiber ring and the temperature signal measured by the temperature sensor are synchronously collected, so as to obtain the temperature characteristics of the tested optical fiber ring through analysis after the temperature test;

[0035] S5. After the test is completed, disconnect the fiber optic ring test device from the optical path signal processing device and the circuit signal processing device; then, take the fiber optic ring test device out of the temperature chamber; then, disconnect the fusion joint between the two pigtails of the fiber optic ring under test and the Y-waveguide optical integrated device in the fiber optic ring test device; then, remove the upper cover, and then you can take out the upper gasket, the fiber optic ring under test, and the lower gasket respectively.

[0036] Compared with the prior art, the high-precision temperature test system for optical fiber ring and the method of using the same have the following beneficial effects:

[0037] (1) The high-precision fiber optic ring temperature test system and method of use of the present application fill the gap in the fiber optic gyroscope fiber optic ring temperature test device in the art, and can well simulate the temperature environment of the fiber optic ring under test in the actual fiber optic gyroscope, and propose a temperature test system that can meet the needs of various temperature environments, and at the same time can reflect the impact of the thermal design of the fiber optic gyroscope housing itself on the temperature performance of the fiber optic ring under test;

[0038] (2) In the high-precision temperature test system for optical fiber rings of the present application, the material used to set the upper cover and the lower cover of the optical fiber ring is the magnetic shielding material 1J79, and after processing, a high-temperature vacuum annealing treatment is performed to improve the magnetic permeability so as to shield the influence of the external magnetic field on the optical fiber ring under test; by designing an upper gasket and a lower gasket between the upper cover and the lower cover to press the optical fiber ring under test in the optical fiber ring test device, not only the influence of environmental vibration on the optical fiber ring under test is avoided, but also the difficulty of installation and disassembly of the optical fiber ring under test is greatly reduced; at the same time, by providing the optical fiber ring pigtail outlet notch, the annular pigtail groove and the narrow pigtail groove on the upper cover and the upper gasket, the smooth routing of the optical fiber ring pigtail is achieved to avoid the pigtail breakage;

[0039] (3) The high-precision fiber optic ring temperature test system of the present application has a reasonable structural design, and the method of implementing temperature testing is simple and easy to use, and it is not easy to damage the fiber optic ring. It has high practical value in the field of fiber optic gyroscope fiber optic ring temperature testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the split structure of the optical fiber ring testing device of the high-precision optical fiber ring temperature testing system of the present invention;

[0041] Figure 2 It is a schematic cross-sectional structure diagram of an optical fiber ring testing device of a high-precision optical fiber ring temperature testing system of the present invention;

[0042] Figure 3 It is a schematic structural diagram of a Y-waveguide optical integrator in an optical fiber ring testing device of a high-precision optical fiber ring temperature testing system of the present invention;

[0043] Figure 4It is a schematic diagram of the routing of the first pigtail of the optical fiber ring to be tested in the optical fiber ring testing device of the high-precision temperature testing system for the optical fiber ring of the present invention;

[0044] Figure 5 It is a schematic diagram of the routing of the second pigtail of the optical fiber ring to be tested in the optical fiber ring testing device of the high-precision temperature testing system for the optical fiber ring of the present invention;

[0045] Figure 6 It is a schematic structural diagram of a temperature sensor in an optical fiber ring testing device of a high-precision optical fiber ring temperature testing system of the present invention;

[0046] Figure 7 It is a structural schematic diagram of a lower cover in a fiber optic ring testing device of a high-precision fiber optic ring temperature testing system of the present invention;

[0047] Figure 8 It is a structural schematic diagram of an upper cover in a fiber optic ring testing device of a high-precision fiber optic ring temperature testing system of the present invention;

[0048] Fig. 9 A flow chart of a method for using the optical fiber ring testing device of the high-precision optical fiber ring temperature testing system of the present invention;

[0049] Fig.10 A schematic diagram of the mechanical assembly process of the optical fiber ring testing device of the high-precision optical fiber ring temperature testing system of the present invention;

[0050] Fig.11 It is a structural schematic diagram of the temperature testing system for the high-precision optical fiber ring of the present invention.

[0051] Among them, 1. Y-waveguide optical integrator, 101. Y-waveguide optical integrator body, 102. first pigtail input terminal, 103. second pigtail input terminal, 104. optical signal output terminal, 2. temperature sensor, 201. temperature sensor body, 202. power ground input terminal, 203. power input terminal, 204. temperature signal output terminal, 3. upper cover, 4. upper gasket, 5. optical fiber ring to be tested, 6. lower gasket, 7. lower cover, 8. first pigtail, 9. second pigtail, 10. optical fiber ring test device, 11. temperature box, 12. optical signal transmission optical fiber, 13. optical path signal processing device, 1301. Fiber optic coupler; 1302. Light source; 1303. Detector; 14. Power ground input electrical signal line of temperature sensor; 15. Power input electrical signal line of temperature sensor; 16. Temperature signal output electrical signal line of temperature sensor; 17. Circuit signal processing device; 1701. Power supply module of temperature sensor; 1702. Temperature signal acquisition module of temperature sensor; 1703. Fiber optic ring signal processing module; 1704. Data output module; 18. Data acquisition storage and processing device; 1801. Data acquisition module; 1802. Data storage module; 1803. Data processing module. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention in any way.

[0053] like Fig.11 As shown, the high-precision temperature test system for optical fiber rings includes an optical fiber ring test device 10 arranged in a temperature box 11 , and an optical path signal processing device 13 , a circuit signal processing device 17 and a data acquisition and processing device 18 arranged outside the temperature box 11 .

[0054] like Figure 1 As shown, the optical fiber ring testing device 10 includes a Y-waveguide optical integrator 1, a temperature sensor 2, an upper cover 3, an upper gasket 4, a lower gasket 6 and a lower cover 7; wherein the lower cover 7, the lower gasket 6, the upper gasket 4 and the upper cover 3 are arranged in sequence from bottom to top, and the Y-waveguide optical integrator 1 and the temperature sensor 2 are arranged on the upper cover 3.

[0055] like Figure 2 As shown, the lower cover 7 is a cylindrical structure with an opening at the top, and an annular partition is fixed inside the cylindrical body. The annular partition is coaxially arranged with the cylindrical body, so that a circular upper cover mounting groove is formed at the center of the cylindrical body, and an annular optical fiber ring mounting groove is formed in the circumference, and the size of the annular optical fiber ring mounting groove is slightly larger than the size of the optical fiber ring 5 to be tested;

[0056] Among them, three cylindrical bosses are evenly distributed along the circumferential direction on the bottom surface of the lower cover 7, and a threaded blind hole is opened on the bottom surface of each cylindrical boss, which is used to fix the high-precision optical fiber ring temperature testing system on the mounting plate in the temperature box by reverse screwing, so as to perform temperature testing; at the same time, the three cylindrical bosses provide routing space for each signal line between the bottom surface of the lower cover 7 and the mounting plate.

[0057] The upper cover 3 is composed of a lower cylindrical body, an annular cylinder extending axially upward from the edge of the top surface of the lower cylindrical body, and an upper annular plate with an inner edge fixed to the top end of the annular cylinder, so that when the lower cylindrical body of the upper cover 3 is inserted into the upper cover mounting groove of the lower cover 7, its upper annular plate cover is installed at the top end opening of the optical fiber ring mounting groove, so that the optical fiber ring mounting groove forms a closed annular space; wherein, the upper cover 3 and the lower cover 7 are detachably fixed as a whole by three countersunk screws evenly installed from the top surface of the lower cylindrical body, and at the same time, the optical fiber ring mounting groove forms a closed space; the closed space is used to simulate the thermal environment of the optical fiber ring 5 under test in the actual optical fiber gyroscope, so that the device can not only serve as a test container to allow the optical fiber ring 5 under test to work in various temperature environments set in the temperature test, but also reflect the effect of the thermal design of the optical fiber gyroscope shell itself on the temperature performance of the optical fiber ring 5 under test.

[0058] In order to ensure that the optical fiber ring 5 under test is always in a test environment shielding the external magnetic field during the test process, the upper cover 3 and the lower cover 7 are made of magnetic shielding material 1J79, and after processing, high-temperature vacuum annealing treatment is performed to improve the magnetic permeability to shield the influence of the external magnetic field on the optical fiber ring under test.

[0059] An outer annular convex strip and an inner annular convex strip are respectively provided at the outer edge and the inner edge of the top surface of the upper annular plate of the upper cover 3, so that an annular pigtail groove is formed therebetween, and a pigtail outlet notch I connected to the optical fiber ring mounting groove is provided on the outer annular convex strip, and a pigtail outlet notch II is provided on the inner annular convex strip which is farthest away from the pigtail outlet notch I, and a first narrow pigtail fixing groove and a second narrow pigtail fixing groove connected to the upper cover mounting groove are respectively provided on both sides of the pigtail outlet notch II, which are used for routing and fixing the two pigtails of the optical fiber ring 5 to be tested when connected to the Y-waveguide optical integrator 1.

[0060] As a preferred technical solution of this application, Figure 8 As shown, two cylindrical bosses are symmetrically provided at the bottom of the upper cover mounting groove of the upper cover 3, and a threaded blind hole is opened axially downward from the top surface of each cylindrical boss, which can be used to screw in screws as a handle for the upper cover 3, so as to improve the convenience of installation and disassembly of the device and the convenience of pigtail routing.

[0061] In order to facilitate the installation and disassembly of the optical fiber ring 5 to be tested, and to keep the optical fiber 5 to be tested in a stable state without vibration during the test, an upper gasket 4 and a lower gasket 6 are arranged in the optical fiber ring installation groove; specifically, the lower gasket 6 is a silicone rubber annular gasket, and its inner diameter and outer diameter are adapted to the size of the optical fiber ring installation groove; the upper gasket 4 is a silicone rubber annular gasket that is completely the same as the lower gasket 6, and a fiber outlet notch for the first pigtail 8 and the second pigtail 9 is opened on one side of the upper gasket 4, which is used for the high-precision fiber pigtail routing of the optical fiber ring 5; the upper gasket 4 and the lower gasket The thickness of 6 satisfies: when the lower gasket 6, the optical fiber ring 5 to be tested and the upper gasket 4 are sequentially stacked from bottom to top as a whole, the thickness is slightly greater than the distance from the bottom of the optical fiber ring mounting groove to the bottom surface of the upper annular plate of the upper cover 3, so that when the upper cover 3 is covered and fixed on the lower cover 6, the optical fiber ring 5 to be tested is tightly pressed between the upper gasket 4 and the lower gasket 6. As a preferred technical solution of the present application, the thickness of the lower gasket 6, the optical fiber ring 5 to be tested and the upper gasket 4 are sequentially stacked from bottom to top as a whole, which is greater than the distance from the bottom of the optical fiber ring mounting groove to the bottom surface of the upper annular plate of the upper cover 3: 1mm;

[0062] In addition, the outer diameters of the upper gasket 4 and the lower gasket 6 are slightly larger than the outer diameter of the optical fiber ring 5 under test, and the inner diameters of the upper gasket 4 and the lower gasket 6 are slightly smaller than the inner diameter of the optical fiber ring 5 under test to ensure that the optical fiber ring 5 under test can be tightly pressed into the sealing groove.

[0063] The Y-waveguide optical integrator 1 is a multifunctional integrated optical device of model YBD-14-2-M produced by Wuhan Changyingtong Optoelectronics Technology Co., Ltd., which is embedded in the Y-waveguide optical integrator installation groove opened at the center of the top surface of the lower cylindrical body of the upper cover 3; Figure 3 As shown, the Y-waveguide optical integrator 1 includes a Y-waveguide optical integrator body 101, on which a first pigtail input terminal 102, a second pigtail input terminal 103 and an optical signal output terminal 104 are arranged; specifically,

[0064] Two screw holes are provided on the Y-waveguide optical integrator body 101, so that two flat head screws are threadedly connected with the threaded holes provided on the upper cover 3 through the screw holes of the Y-waveguide optical integrator 1, thereby fixing the Y-waveguide optical integrator 1 on the upper cover 3;

[0065] The first pigtail input terminal 102 is connected to the first pigtail 8 of the optical fiber ring 5 under test, and the second pigtail input terminal 103 is connected to the second pigtail 9 of the optical fiber ring 5 under test; when in use, Figure 4As shown, the first pigtail 8 of the optical fiber ring 5 to be tested, which is arranged in the optical fiber ring installation groove of the lower cover 7, is led out through the fiber outlet notch of the upper gasket 4 and the pigtail outlet notch I of the upper cover 3 in sequence, and is routed along the left side of the annular pigtail groove opened in the upper cover 3, until it enters and is fixed in the first narrow pigtail fixing groove from the pigtail outlet notch II of the upper cover 3, and its end is connected to the first pigtail input terminal 102 of the Y-waveguide optical integrator 1; then, as shown in FIG. Figure 5 As shown, the second pigtail 9 of the optical fiber ring 5 to be tested is led out through the fiber outlet notch of the upper gasket 4 and the pigtail outlet notch I of the upper cover 3 in sequence, and runs along the right side of the annular pigtail groove opened in the upper cover 3, until it enters and is fixed in the second narrow pigtail fixing groove from the pigtail outlet notch II of the upper cover 3, and its end is connected to the second pigtail input terminal 103 of the Y-waveguide optical integrator 1; the optical signal output terminal 104 is connected to the optical signal transmission optical fiber 12, which is used for light input from an external light source on the one hand, and for outputting interference light generated in the Y-waveguide by two beams of light in opposite directions in the optical fiber ring on the other hand.

[0066] The temperature sensor 2 is a DS18B20 temperature sensor, which is embedded in a temperature sensor installation groove on the top surface of the lower cylindrical body of the upper cover 3, and the lower plane of the temperature sensor 2 is glued to the bottom surface of the temperature sensor installation groove by glue to connect them as a whole;

[0067] like Figure 6 As shown, the temperature sensor 2 includes a temperature sensor body 201, on which a power ground input terminal 202, a power +5V input terminal 203 and a temperature signal output terminal 204 are provided; specifically, the power ground input terminal 202 is connected to a power ground input electrical signal line 14, the power +5V input terminal 203 is connected to a power +5V input electrical signal line 15, and the temperature signal output terminal 204 is connected to a temperature signal output electrical signal line 16; Figure 7 As shown, the three electrical signal lines respectively pass through the arc-shaped through holes opened from the top surface of the upper cover mounting groove of the upper cover 3 and penetrate to the bottom surface of the lower cover 7, and then are output to the external circuit signal processing device 17 through the wiring space.

[0068] The optical path signal processing device 13 includes an optical fiber coupler 1301, a light source 1302 and a detector 1303; specifically, one end of the optical fiber coupler 1301 is connected to the optical signal output terminal 104 in the optical fiber ring test device 10 through the optical signal transmission optical fiber 12, and the other end is connected to the light source 1302 and the detector 1303 respectively through the optical signal transmission optical fiber;

[0069] The specific process is as follows: the light source 1302 provides a light source for the optical fiber ring 5 to be tested in the optical fiber ring testing device 10; the optical fiber coupler 1301 is used for light transmission and splitting, and one end of the optical fiber coupler has a single pigtail, which is connected to the optical signal output terminal 104 of the Y-waveguide optical integrator 1 through the optical signal transmission optical fiber 12; the other end of the optical fiber coupler 1301 has a double pigtail, one of which is connected to the light source 1302 for transmitting the light provided by the light source 1302 to the optical fiber ring 5 to be tested via the Y-waveguide optical integrator 1, and the other pigtail is connected to one end of the detector 1303 for transmitting the interference light signal formed by the two beams of light transmitted in opposite directions from the optical fiber ring transmitted from the Y-waveguide optical integrator 1 to the detector 1303; the other end of the detector 1303 is connected to the circuit signal processing device 17, and the detector 1303 converts the interference light signal formed by the two beams of light transmitted in opposite directions in the optical fiber ring 5 to be tested fed back by the Y-waveguide optical integrator 1 into an electrical signal and transmits it to the circuit signal processing device 17.

[0070] The circuit signal processing device 17 includes a temperature sensor power supply module 1701, a temperature sensor temperature signal acquisition module 1702, an optical fiber ring signal processing module 1703 and a data transmission module 1704; specifically,

[0071] The negative electrode and the positive electrode of the temperature sensor power supply module 1701 are respectively welded to the other end of the power ground input electrical signal line 14 and the power +5V input electrical signal line 15 to supply power to the temperature sensor 2;

[0072] The temperature sensor temperature signal acquisition module 1702 is welded and connected to the temperature signal output electrical signal line 16 of the temperature sensor 2, and is used to acquire the temperature signal detected by the temperature sensor 2;

[0073] The optical fiber ring signal processing module 1703 is connected to the detector 1303 through an optical signal output electrical signal line, and is used to collect the interference optical signal formed by two beams of light transmitted in opposite directions in the measured optical fiber ring 5 fed back by the Y-waveguide optical integrator 1;

[0074] The data transmission module 1704 is connected to the temperature sensor temperature signal acquisition module 1702 and the optical fiber ring signal processing module 1703 through signal transmission lines, and is used to collect the temperature sensor temperature signal and the optical fiber ring signal to transmit them to the data acquisition and processing device 18.

[0075] The data acquisition and processing device 18 includes a data acquisition module 1801, a data storage module 1802 and a data processing module 1803; specifically, the data acquisition module 1801 is connected to the data transmission module 1704 through a signal transmission line, and is used to receive the temperature signal of the temperature sensor and the optical fiber ring signal; the data storage module 1802 is used to store the data collected by the data acquisition module 1801 on a storage medium; the data processing module 1803 is used to analyze the temperature signal of the temperature sensor and the optical fiber ring signal to obtain the temperature characteristic index of the optical fiber ring 5 under test.

[0076] In this embodiment, the temperature signal of the temperature sensor is specifically the ambient temperature in the temperature box 11 measured in real time, and the fiber optic ring signal is specifically the angular velocity signal to which the fiber optic ring 5 under test is sensitive. By analyzing the data results of the two, the temperature characteristics of the fiber optic ring 5 under test can be obtained, and then the temperature index of the fiber optic ring can be effectively evaluated.

[0077] like Fig. 9 and Fig.10 As shown, the specific method of using the above-mentioned high-precision fiber optic ring temperature test system to implement temperature testing is as follows:

[0078] S1, completing the mechanical assembly of the optical fiber ring testing device 10;

[0079] Place the lower gasket 6, the optical fiber ring 5 to be tested and the upper gasket 4 into the optical fiber ring installation groove of the lower cover 7 in sequence, and cover the upper cover 3, and use three countersunk screws to thread the upper cover 3 to the threaded holes of the lower cover 7 through the three countersunk light holes of the upper cover 3 to fix the upper cover 3 to the lower cover 7, so as to realize the connection and fixation of the upper gasket 4, the optical fiber ring 5 to be tested, the lower gasket 6 and the lower cover 7 as a whole;

[0080] Place the temperature sensor 2 in the temperature sensor installation groove opened in the upper cover 3 and glue the lower plane of the temperature sensor 2 to the upper plane of the temperature sensor installation groove opened in the upper cover 3;

[0081] Place the Y-waveguide optical integrator 1 on the Y-waveguide optical integrated device installation slot provided on the upper cover 3 and fix the Y-waveguide optical integrator 1 on the upper cover 3 by threading through the screw holes of the Y-waveguide optical integrator 1 and the threaded holes of the upper cover 3 with two flat head screws;

[0082] S2. Complete the fusion splicing of optical fibers in the device:

[0083] The first pigtail 8 of the optical fiber ring 5 to be tested is fused; specifically, as Figure 4As shown, the first pigtail 8 of the optical fiber ring 5 to be tested is led out through the fiber outlet notch of the upper gasket 4 and the pigtail outlet notch I of the upper cover 3 in sequence, and then runs along the left side of the annular pigtail groove opened in the upper cover 3 until it passes through the pigtail outlet notch II and enters the first narrow pigtail groove entrance and is fixed in the first narrow pigtail groove, and the end of the first pigtail 8 extends into the circular groove of the upper cover 3 and is connected to the first pigtail input terminal 102 of the Y-waveguide optical integrator 1;

[0084] The second pigtail 9 of the optical fiber ring 5 to be tested is fused; specifically, as Figure 5 As shown, the second pigtail 9 of the optical fiber ring 5 to be tested is led out through the fiber outlet notch of the upper gasket 4 and the pigtail outlet notch I of the upper cover 3 in sequence, and then runs along the right side of the annular pigtail groove opened in the upper cover 3 until it passes through the pigtail outlet notch II and enters the entrance of the second narrow pigtail groove and is fixed in the second narrow pigtail groove, and the end of the second pigtail 9 extends into the circular groove of the upper cover 3 and is connected to the second pigtail input terminal 103 of the Y-waveguide optical integrator 1;

[0085] The optical signal transmission fiber 12 is fused; specifically, the optical signal transmission fiber 12 is fused to the optical signal output terminal 104 of the Y-waveguide optical integrator 1, and finally the optical signal transmission fiber 12 is led to the external optical path signal processing device 13;

[0086] S3, completing the welding of the electrical signal wire of the temperature sensor in the device;

[0087] First, the power ground input electrical signal line 14 is welded to the power ground input terminal 202 of the temperature sensor 2, the power +5V input electrical signal line 15 is welded to the power +5V input terminal 203 of the temperature sensor 2, and the temperature signal output electrical signal line 16 is welded to the temperature signal output terminal 204 of the temperature sensor 2; then, the power ground input electrical signal line 14, the power +5V input electrical signal line 15 and the temperature signal output electrical signal line 16 led out from the power ground input terminal 202, the power +5V input terminal 203 and the temperature signal output terminal 204, a total of three electrical signal lines, are passed through the circular through hole opened on the circular groove of the upper cover 3 and the arc-shaped through hole opened on the upper cover mounting groove of the lower cover 7 to reach the space formed by the three cylindrical bosses of the lower cover 7 and connected to the external circuit signal processing device 17.

[0088] S4, such as Fig.11 As shown, the device is placed in a test system for testing;

[0089] First, fix the assembled optical fiber ring test device 10 for temperature testing of high-precision optical fiber rings in the temperature box 11 by reversely screwing the screws; fuse the optical signal transmission optical fiber 12 of the optical fiber ring test device 10 with the optical fiber coupler 1301 of the optical path signal processing device 13; then, weld the power ground input electrical signal line 14 and the power +5V input electrical signal line 15 of the temperature sensor 2 of the optical fiber ring test device 10 with the temperature sensor power supply module 1701 of the circuit signal processing device 17, and weld the temperature signal output electrical signal line 16 of the temperature sensor 2 of the optical fiber ring test device 10 with the temperature sensor temperature signal acquisition module 1702; then, press the temperature test The temperature setting requirement controls the temperature box 11 to perform the temperature test, and at the same time, during the test, the data acquisition module 1801 of the data acquisition storage and processing device 18 is used to collect the angular velocity signal of the optical fiber ring 5 under test and the temperature signal measured by the temperature sensor 2 output by the data output module 1704 of the circuit signal processing device 17, and the collected data is stored in the data storage module 1802 of the data acquisition storage and processing device 18; finally, after the temperature test, the data processing module 1803 of the data acquisition storage and processing device 18 is used to perform data analysis and processing on the angular velocity signal of the optical fiber ring 5 under test and the temperature signal measured by the temperature sensor 2 to obtain the temperature characteristics of the optical fiber ring 5 under test;

[0090] S5. After the test is completed, the optical signal transmission fiber 12 of the fiber optic ring test device 10 is disconnected from the optical path signal processing device 13, and the three electrical signal lines of the temperature sensor 2 are disconnected from the circuit signal processing device 17; then, the fiber optic ring test device 10 is taken out of the temperature box 11; after that, the two pigtails of the fiber optic ring in the fiber optic ring test device 10 and the fusion connection of the Y-waveguide optical integrated device 1 are disconnected; then, the upper cover 3 is removed, and the upper gasket 4, the tested fiber optic ring 5 and the lower gasket 6 can be taken out respectively.

Claims

1. A method for temperature testing using a high-precision temperature testing system for an optical fiber ring, characterized in that: The high-precision optical fiber ring temperature test system comprises an optical fiber ring test device (10) arranged in a temperature box (11), and an optical path signal processing device (13), a circuit signal processing device (17) and a data acquisition and processing device (18) arranged outside the temperature box (11); the optical fiber ring test device (10) comprises a lower cover (7), a lower gasket (6), an upper gasket (4) and an upper cover (3) arranged in order from bottom to top, as well as a Y-waveguide optical integrator (1) and a temperature sensor (2); the lower cover (7) is provided with an open cylinder at the top end, a circular upper cover mounting groove is provided at the center thereof, and an annular optical fiber ring mounting groove is formed in the circumference; the upper cover (3) is composed of a lower columnar The optical fiber ring installation groove is composed of a body, an annular cylinder extending axially upward from the edge of the top surface of the lower cylindrical body, and an upper annular plate whose inner edge is fixed to the top end of the annular cylinder, so that when the lower cylindrical body of the upper cover (3) is inserted into the upper cover installation groove of the lower cover (7), the upper annular plate cover is installed at the top end opening of the optical fiber ring installation groove, so that the optical fiber ring installation groove forms a closed annular space; the lower gasket (6) and the upper gasket (4) are two annular gaskets with the same structure and size, and the two are built into the optical fiber ring installation groove; the Y-waveguide optical integrator (1) comprises a Y-waveguide optical integrator body (101) embedded in the upper cover (3), on which is provided a first pigtail for connecting with the optical fiber ring (5) to be tested. (8) connected to the first pigtail input terminal (102), the second pigtail input terminal (103) connected to the second pigtail (9) of the optical fiber ring (5) to be tested, and an optical signal output terminal (104); the temperature sensor (2) comprises a temperature sensor body (201) embedded in the upper cover (3), on which are provided a power ground input terminal (202) connected to the power ground input electrical signal line (14), a power input terminal (203) connected to the power input electrical signal line (15), and a temperature signal output terminal (204) connected to the temperature signal output electrical signal line (16); the optical path signal processing device (13) and the optical signal output terminal The circuit signal processing device (17) is connected to the optical path signal processing device (13) to input the light source signal provided by the light source (1302) to the Y-waveguide optical integrator (1) and receive the optical signals of the two beams of light transmitted in opposite directions in the optical fiber ring (5) under test fed back by the Y-waveguide optical integrator (1); the circuit signal processing device (17) is respectively connected to the power ground input electrical signal line (14), the power input electrical signal line (15) and the temperature signal output electrical signal line (16) to supply power to the temperature sensor (2) and collect the temperature signal; the circuit signal processing device (17) is connected to the optical path signal processing device (13) to collect the optical signal output by the optical path signal processing device (13) and convert it into an electrical signal; the data acquisition and processing device (18) is connected to the circuit signal processing device (17) to collect, store and process the output optical signal and temperature signal to obtain the temperature characteristic index of the optical fiber ring (5) under test; The optical path signal processing device (13) comprises an optical fiber coupler (1301), a light source (1302) and a detector (1303); one end of the optical fiber coupler (1301) is connected to an optical signal output terminal (104) in the optical fiber ring testing device (10) via an optical signal transmission optical fiber (12), and the other end is connected to the light source (1302) and the detector (1303) respectively via optical signal transmission optical fibers; The circuit signal processing device (17) comprises a temperature sensor power supply module (1701), a temperature sensor temperature signal acquisition module (1702), an optical fiber ring signal processing module (1703) and a data transmission module (1704); the negative electrode and the positive electrode of the temperature sensor power supply module (1701) are respectively connected to the other end of the power ground input electrical signal line (14) and the power input electrical signal line (15) to supply power to the temperature sensor (2); the temperature sensor temperature signal acquisition module (1702) is connected to the temperature signal output electrical signal line (16) of the temperature sensor (2) to acquire the temperature signal from the temperature sensor (2); the optical fiber ring signal processing module (1703) is connected to the detector (1303) via the optical signal output electrical signal line to acquire the optical signal output by the optical fiber ring and convert it into an electrical signal; the data transmission module (1704) is respectively connected to the temperature sensor temperature signal acquisition module (1702) and the optical fiber ring signal processing module (1703) via the signal transmission line to output the optical signal and the temperature signal converted into an electrical signal to the outside; The data acquisition and processing device (18) comprises a data acquisition module (1801), a data storage module (1802) and a data processing module (1803); the data acquisition module (1801) is connected to the data transmission module (1704) via a signal transmission line to receive optical signals and temperature signals converted into electrical signals; the data storage module (1802) is connected to the data acquisition module (1801) via a signal transmission line to store the optical signals and temperature signals converted into electrical signals on a storage medium; the data processing module (1803) is connected to the data storage module (1802) via a signal transmission line to process the optical signals and temperature signals converted into electrical signals and obtain temperature characteristic indicators of the optical fiber ring (5) under test; An outer annular convex strip and an inner annular convex strip are respectively provided at the outer edge and the inner edge of the top surface of the upper annular plate of the upper cover (3), so that an annular pigtail groove is formed between the two, and a pigtail outlet notch I connected to the optical fiber ring mounting groove is provided on the outer annular convex strip, and a pigtail outlet notch II is provided on the inner annular convex strip which is farthest from the pigtail outlet notch I, and a first narrow pigtail fixing groove and a second narrow pigtail fixing groove connected to the upper cover mounting groove are respectively provided on both sides of the pigtail outlet notch II; a fiber outlet notch is provided on the upper gasket (4) located below the pigtail outlet notch; The steps for using the temperature test are as follows: S1. Assembling the optical fiber ring test device (10): placing the lower gasket (6), the optical fiber ring to be tested (5) and the upper gasket (4) in the optical fiber ring installation groove of the lower cover (7) in sequence, and then installing and fixing the upper cover (3) so that the lower cover (7), the lower gasket (6), the optical fiber ring to be tested (5), the upper gasket and the upper cover (3) are coaxially arranged and fixed as a whole; fixing the Y-waveguide optical integrator (1) and the temperature sensor (2) on the upper cover (3); S2. The circuit of the Y-waveguide optical integrator is fused, including: the first pigtail (8) of the optical fiber ring (5) to be tested is led out through the fiber outlet notch of the upper gasket (4) and the pigtail outlet notch I of the upper cover (3) in sequence, and then the fiber is routed along the left side of the annular pigtail groove opened in the upper cover (3) until it passes through the pigtail outlet notch II and enters the first narrow pigtail groove entrance and is fixed in the first narrow pigtail groove, the end of the first pigtail (8) extends into the circular groove of the upper cover (3) and is connected to the first pigtail input terminal (102) of the Y-waveguide optical integrator (1); the second pigtail (9) of the optical fiber ring (5) to be tested is led out through the fiber outlet notch of the upper gasket (4), the upper cover ( 3), and then run along the right side of the annular pigtail groove opened in the upper cover (3) until it passes through the pigtail groove II and enters the entrance of the second narrow pigtail groove and is fixed in the second narrow pigtail groove, the end of the second pigtail (9) extends into the circular groove of the upper cover (3) and is connected to the second pigtail input terminal (103) of the Y-waveguide optical integrator (1); one end of the optical signal transmission optical fiber (12) is fused to the optical signal output terminal (104) of the Y-waveguide optical integrator (1), and the other end of the optical signal transmission optical fiber (12) is fused to the single pigtail end of the optical fiber coupler (1301) of the optical path signal processing device (13); S3, welding the circuits of the temperature sensor: welding the power ground input electric signal line (14) to the power ground input terminal (202), welding the power input electric signal line (15) to the power input terminal (203), and welding the temperature signal output electric signal line (16) to the temperature signal output terminal (204); then passing the power ground input electric signal line (14), the power input electric signal line (15), and the temperature signal output electric signal line (16) in parallel through the circular through hole opened on the circular groove of the upper cover (3) and the arc-shaped through hole opened on the upper cover mounting groove of the lower cover (7) to reach the space formed by the support of the three cylindrical bosses of the lower cover (7), and then connected to the external circuit signal processing device (17); S4, performing a temperature test on the optical fiber ring under test: fixing the optical fiber ring test device (10) in a temperature box (11); passing the optical signal transmission optical fiber (12), the power ground input electrical signal line (14), the power input electrical signal line (15) and the temperature signal output electrical signal line (16) through the wire holes provided on the temperature box (11); then, welding the optical signal transmission optical fiber (12) to the optical fiber coupler (1301); welding the power ground input electrical signal line (14) and the power input electrical signal line (15) to the negative electrode and the positive electrode of the temperature sensor power supply module (1701), respectively; welding the temperature signal output electrical signal line (16) to the temperature sensor temperature signal acquisition module (1702); then, setting the temperature of the temperature box (11) according to the temperature setting requirements of the temperature test, and synchronously collecting the sensitive angular velocity signal fed back by the optical fiber ring under test (5) and the temperature signal measured by the temperature sensor (2) during the test, so as to obtain the temperature characteristics of the optical fiber ring under test (5) through analysis after the temperature test; S5. After the test is completed, the optical fiber ring test device (10) is disconnected from the optical path signal processing device (13) and the circuit signal processing device (17); then, the optical fiber ring test device (10) is taken out of the temperature chamber (11); then, the fusion joint between the two pigtail Y-waveguide optical integrated devices (1) of the optical fiber ring (5) under test in the optical fiber ring test device (10) is disconnected; then, the upper cover (3) is removed, and the upper gasket (4), the optical fiber ring under test (5) and the lower gasket (6) are taken out respectively.

2. The method for temperature testing using a high-precision optical fiber ring temperature testing system according to claim 1, characterized in that: Two cylindrical bosses are symmetrically arranged at the bottom of the upper cover mounting groove of the upper cover (3), and a threaded blind hole is opened axially downward from the top surface of each cylindrical boss to screw in a screw as a handle of the upper cover (3).

3. The method for temperature testing using a high-precision optical fiber ring temperature testing system according to claim 1, characterized in that: The sizes of the upper gasket (4) and the lower gasket (6) are adapted to the sizes of the optical fiber ring installation groove, and the thicknesses of the upper gasket (4) and the lower gasket (6) satisfy the following conditions: when the lower gasket (6), the optical fiber ring (5) to be measured and the upper gasket (4) are sequentially stacked from bottom to top, the thickness of the whole is slightly greater than the distance from the bottom of the optical fiber ring installation groove to the bottom surface of the upper annular plate of the upper cover (3), so that the optical fiber ring (5) to be measured can be pressed and fixed in the optical fiber ring installation groove; the outer diameter of the optical fiber ring (5) to be measured is slightly smaller than the outer diameters of the upper gasket (4) and the lower gasket (6); and the inner diameters of the upper gasket (4) and the lower gasket (6) are both slightly smaller than the inner diameter of the optical fiber ring (5) to be measured.

4. The method for temperature testing using a high-precision temperature testing system for an optical fiber ring according to claim 1, characterized in that: Three cylindrical bosses are evenly distributed along the circumferential direction on the bottom surface of the lower cover (7), and a threaded blind hole is opened axially upward from the bottom surface of each cylindrical boss, so that the optical fiber ring test device (10) is fixed on the mounting plate of the temperature box and a wiring space is left between the lower cover (7) and the mounting plate; an arc-shaped through hole is opened from the upper cover (3) and penetrates the upper cover (3) and the lower cover (7).

5. The method for temperature testing using a high-precision optical fiber ring temperature testing system according to claim 1, characterized in that: The upper cover (3) and the lower cover (7) are both made of magnetic shielding material 1J79, and are subjected to high-temperature vacuum annealing after processing to improve magnetic permeability; the upper gasket (4) and the lower gasket (6) are ring-shaped gaskets made of silicone rubber.

Images