CN114112172B - Micro pressure optical measurement method and calibration device - Google Patents
Micro pressure optical measurement method and calibration device Download PDFInfo
- Publication number
- CN114112172B CN114112172B CN202111349631.0A CN202111349631A CN114112172B CN 114112172 B CN114112172 B CN 114112172B CN 202111349631 A CN202111349631 A CN 202111349631A CN 114112172 B CN114112172 B CN 114112172B
- Authority
- CN
- China
- Prior art keywords
- pressure
- cavity
- laser
- micro
- volume
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 39
- 238000000691 measurement method Methods 0.000 title claims abstract description 11
- 238000012360 testing method Methods 0.000 claims abstract description 81
- 230000007246 mechanism Effects 0.000 claims abstract description 41
- 230000008859 change Effects 0.000 claims abstract description 15
- 230000005540 biological transmission Effects 0.000 claims abstract description 14
- 238000005259 measurement Methods 0.000 claims abstract description 14
- 238000004556 laser interferometry Methods 0.000 claims abstract description 9
- 230000003068 static effect Effects 0.000 claims abstract description 7
- 238000002955 isolation Methods 0.000 claims description 8
- 230000001105 regulatory effect Effects 0.000 claims description 6
- 238000006073 displacement reaction Methods 0.000 claims description 3
- 230000005284 excitation Effects 0.000 claims description 3
- 238000007789 sealing Methods 0.000 claims description 3
- 230000001276 controlling effect Effects 0.000 claims description 2
- 238000000034 method Methods 0.000 claims description 2
- 238000012545 processing Methods 0.000 claims description 2
- 238000009530 blood pressure measurement Methods 0.000 abstract description 18
- 230000004044 response Effects 0.000 abstract description 4
- 230000035945 sensitivity Effects 0.000 abstract description 4
- 239000000523 sample Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000007123 defense Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L11/00—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00
- G01L11/02—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00 by optical means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L27/00—Testing or calibrating of apparatus for measuring fluid pressure
- G01L27/002—Calibrating, i.e. establishing true relation between transducer output value and value to be measured, zeroing, linearising or span error determination
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
The invention discloses a micro pressure optical measurement method and a calibration device, and belongs to the technical field of metering test. The invention mainly comprises a vibrating table, a piston, a variable volume mechanism, a pressure test cavity, a laser interferometry system and a control system. The pressure testing cavity is connected with the variable-volume mechanism, the vibrating table is connected with the piston rod, the piston rod penetrates into the variable-volume mechanism, the vibrating table moves to drive the variable-volume mechanism to change the volume of the pressure cavity, and meanwhile the pressure in the pressure testing cavity is driven to change. The high-precision tracing of the micro pressure is realized by utilizing a laser interference optical system, wherein a plurality of high reflection surfaces are arranged in a pressure test cavity, the laser transmission path in the cavity is increased by reflecting incident light for multiple times, the measuring optical path is increased in a small-size pressure cavity, the contradiction between the cavity length and the pressure stability and dynamic response is solved, the sensitivity and the precision of pressure measurement are improved, and the accurate measurement and calibration of the micro static or dynamic pressure can be realized.
Description
Technical Field
The invention relates to a micro pressure optical measurement method and a calibration device, and belongs to the technical field of metering test.
Background
Pressure is one of the important parameters for mechanical metering and testing, and is widely applied in the fields of aviation, aerospace, nuclear industry, ships, weapons and the like. In the national defense industry test process, the accuracy of the pressure magnitude directly influences the safety and development of various fields of the national defense industry. In order to improve the accuracy of pressure measurement, people fully utilize the characteristics of high accuracy, high resolution and high dynamic of optical measurement such as laser interference, and the optical measurement means is used for pressure measurement, so that the pressure measurement accuracy is improved to a certain extent, and a pressure standard and a dynamic pressure standard with higher accuracy are hopefully established. The refractive index-based optical pressure measurement is the most commonly used laser pressure measurement mode at present, and the measurement principle is that a laser interferometer is used for measuring the variation of the optical path (namely the physical cavity length multiplied by the refractive index of the gas) of the laser passing through the gas pressure cavity, so as to obtain the refractive index variation of the gas in the pressure cavity, and further obtain the pressure value. Patent CN 106153249a, and patent CN 108955997a, all disclose that pressure measurement and tracing under different media are accomplished by using a laser interferometry optical system. The accuracy of pressure measurement is limited by the length dimensions of the laser interferometer and the pressure cavity, and for a laser interferometer of the same performance, the larger the cavity length dimension is, the higher the sensitivity of pressure measurement is, but due to the increase of the pressure measurement space, the pressure stability and dynamic response in the corresponding cavity are also deteriorated. This contradiction is more pronounced especially when carrying out high-precision measurements of minute pressures.
Disclosure of Invention
In order to solve the problem that in the existing optical pressure measurement, the accurate measurement of the micro pressure is difficult due to contradiction between the cavity length and the pressure stability and dynamic response, the invention aims to provide the optical measurement method and the calibration device for the micro pressure, which can realize the high-precision measurement and the calibration of the optical micro pressure in a small space environment and improve the sensitivity and the precision of the pressure measurement. The invention can be used for accurate measurement and calibration of static micro pressure and dynamic micro pressure.
The invention aims at realizing the following technical scheme:
The invention discloses a micro-pressure optical calibration device which mainly comprises a vibrating table, a piston, a variable volume mechanism, a pressure test cavity, a laser interferometry system and a control system.
The pressure testing cavity is connected with the variable-volume mechanism, the vibrating table is connected with the piston rod, the piston rod penetrates into the variable-volume mechanism, the vibrating table moves to drive the variable-volume mechanism to change the volume of the pressure cavity, and meanwhile the pressure in the pressure testing cavity is driven to change.
A laser head in the laser interferometry system is fixed on a vibration isolation platform, and the vibration isolation platform is in non-contact with the vibration platform, the piston, the variable-volume mechanism and the pressure test cavity.
The pressure test cavity is internally provided with a plurality of high reflection surfaces for realizing multiple reflections of the optical path in the cavity and increasing the laser transmission path.
The lateral wall of the pressure test cavity is provided with a light passing hole for transmitting laser signals and the outside.
The number of the high reflection surfaces in the pressure test cavity is two or more, and by setting the positions of the reflection surfaces and adjusting the angle of incident light, the increase of the transmission path of laser in the pressure test cavity is realized, and reflected light is returned to the laser probe of the laser interferometer.
The lower wall of the pressure testing cavity is provided with a mounting interface and a pressure transmission window which are used for being communicated with the tested gas so that the gas pressure in the pressure testing cavity is consistent with the gas pressure in the variable-volume mechanism;
the pressure test cavity side wall has one or more light-passing holes, and a reflecting mirror is arranged outside the holes to reflect laser back into the pressure test cavity.
The pressure regulating structure is connected with an air source and a vacuum pump and is used for controlling the initial pressure of the pressure testing cavity.
The volume-variable mechanism adopts a cylindrical structure, and the relation between the internal generated pressure p (t) and the vibration displacement x (t) is as follows:
Wherein L 0 is the equivalent length, and the calculation formula is as follows: D 0 is the internal diameter of the variable volume mechanism, V 0 is the initial volume of the variable volume mechanism, P s is the initial pressure, and γ is the specific heat ratio of the medium.
The invention discloses a micro pressure optical measurement method, which comprises the following steps:
Step one: and opening the upper cover of the pressure testing cavity, opening the laser vibration meter, and enabling laser to enter the pressure testing cavity by adjusting the incidence position and angle of the laser and return to a laser head of the laser vibration meter after multiple reflections. By changing the incidence position and angle of the laser head, the change of different laser transmission paths in the pressure cavity is realized.
Step two: and (5) covering an upper cover of the pressure testing cavity, and sealing and installing.
Step three: the pressure test cavity is filled with a gas medium.
Step four: adjusting the pressure control system to enable the pressure in the pressure measurement cavity to be static initial pressure; if the dynamic micro pressure is required to be measured, the vibrating table is opened to generate excitation, so that the pressure change is generated in the variable-volume mechanism, and the dynamic micro pressure is generated in the pressure measurement test cavity.
Step five: and acquiring and processing the optical path change signal measured by the laser interferometer to obtain a micro pressure value of the pressure test cavity, namely realizing micro pressure optical measurement.
The beneficial effects are that:
1. the invention discloses a micro pressure optical measurement method and a calibration device, which realize high-precision tracing of micro pressure by utilizing a laser interference optical system, wherein a plurality of high reflection surfaces are arranged in a pressure test cavity, the laser transmission path in the cavity is increased by repeated reflection of incident light, the measurement optical path is increased in a small-size pressure cavity, the contradiction between the cavity length, the pressure stability and the dynamic response is solved, the sensitivity and the precision of pressure measurement are improved, and the accurate measurement and calibration of micro static or dynamic pressure can be realized.
2. The invention discloses a micro pressure optical measurement method and a calibration device, wherein two opposite inner surfaces in a pressure test cavity are high reflection surfaces, and the two high reflection surfaces are planes parallel to each other and are used for realizing mutual reflection of laser and increasing optical path.
3. The invention discloses a micro pressure optical measurement method and a calibration device, wherein a light through hole is respectively formed in the side wall of a pressure test cavity where two high reflection surfaces are located, and incident light emitted by a laser head of a laser interferometer enters the pressure test cavity through the light through hole. The incident angle of the incident light is adjusted, so that laser light generates multiple mutual reflections on two high reflection surfaces in the pressure test cavity, and finally passes through another light through hole to be transmitted out of the pressure test cavity. And a reflecting mirror is arranged outside the light passing hole, a laser signal is reflected back into the pressure testing cavity, the angle of the reflecting mirror is adjusted, reflected light returns according to an original path and returns to a laser probe of the laser interferometer through the light passing hole, and then a laser interference optical system is utilized to realize high-precision tracing of micro pressure in the small-size pressure cavity.
Drawings
Fig. 1 is a schematic structural diagram of an optical calibration device for micro pressure according to the present invention.
FIG. 2 is a schematic diagram of a pressure testing chamber device according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of a pressure measurement laser transmission line.
The device comprises a 1-vibration table, a 2-piston, a 3-volume-changing mechanism, a 4-pressure test cavity, a 5-laser interferometry system, a 6-control system and a 7 vibration isolation platform, wherein the vibration isolation platform is arranged on the 1-vibration table;
41-high reflection surface, 42-light through hole, 43-installation interface, 44-pressure transmission window, 51-laser interferometer, 52-laser head, 53-reflector, 54-incident light, 55-reflected light, 61-pressure regulating mechanism, 62-air source, 63-vacuum pump.
Detailed Description
The invention is further described in detail below with reference to the drawings and examples. The embodiment gives a specific implementation mode on the premise of the technical scheme of the invention, but the protection scope of the invention is not limited to the following embodiment.
As shown in fig. 1, the micro pressure optical measurement device disclosed in the embodiment mainly comprises a vibrating table 1, a piston 2, a variable volume mechanism 3, a pressure test cavity 4, a laser interferometry system 5 and a control system 6;
The pressure testing cavity 4 is connected with the variable volume mechanism 3, is internally communicated, the vibrating table 1 is connected with the piston 2 rod, the piston 2 rod penetrates deep into the variable volume mechanism 3, and the pressure regulating mechanism 61 is connected with the variable volume mechanism 3 and is used for regulating the static initial pressure of the variable volume mechanism 3. The vibration table 1 moves to drive the volume-changing mechanism 3 to change the volume of the pressure cavity, so that the pressure in the pressure testing cavity 4 can be driven to generate dynamic change;
the volume-variable mechanism 3 adopts a cylindrical structure, and the relationship between the internal generated pressure p (t) and the vibration displacement x (t) is as follows:
Wherein L 0 is the equivalent length, and the calculation formula is as follows: D 0 is the internal diameter of the variable volume mechanism 3, V 0 is the initial volume of the variable volume mechanism 3, P s is the initial pressure, and γ is the specific heat ratio of the medium.
The laser head 52 in the laser interferometry system 5 is fixed on the vibration isolation platform 7, and the vibration isolation platform 7 is in non-contact with the vibration platform 1, the piston 2, the variable volume mechanism 3 and the pressure test cavity 4;
The pressure testing cavity 4 is of a rectangular structure, a pressure transmission window 43 is formed in one side wall of the pressure testing cavity, a mounting interface 44 is arranged on the outer side of the window and used for completing assembly with the variable volume mechanism 3, and tested gas enters the pressure testing cavity 4 through the pressure transmission window 44, so that the gas pressure in the pressure testing cavity 4 is consistent with the gas pressure in the variable volume mechanism 3.
The two opposite inner surfaces in the pressure testing cavity 4 are high reflection surfaces 41, and the two high reflection surfaces 41 are planes parallel to each other and are used for realizing mutual reflection of laser and increasing optical path.
The side walls of the pressure test cavity 4 where the two high reflection surfaces 41 are located are respectively provided with a light through hole 42, and incident light 54 emitted by a laser head 52 of the laser interferometer 51 enters the pressure test cavity 4 through one light through hole 42 a. The incident angle of the incident light 54 is adjusted, so that the laser light generates multiple mutual reflections on the two high reflection surfaces 41 in the pressure test cavity 4, and finally passes out of the pressure test cavity 4 through the other light through hole 42 b. A reflecting mirror 53 is disposed outside the light passing hole 42b to reflect the laser signal back into the pressure test chamber 4, and the angle of the reflecting mirror 53 is adjusted to return the reflected light 55 in the original path and return to the laser probe 52 of the laser interferometer 51 through the light passing hole 42 a.
The embodiment discloses an optical measurement method for micro pressure, which comprises the following specific implementation steps:
step one: opening the upper cover of the pressure testing cavity 4, opening the laser vibration meter 51, adjusting the incident laser 54 to smoothly enter the pressure testing cavity 4 through the light-passing hole 42a, generating multiple refraction in the cavity, and then transmitting the laser out of the pressure testing cavity 4 through the light-passing hole 42 b;
step two: the position and angle of the reflecting mirror 53 are adjusted, so that the reflected laser 54 smoothly enters the light-passing hole 42b, and returns to the laser head 52 through the light-passing hole 42a after being refracted for a plurality of times in the pressure test cavity 4;
step three: the light path in the pressure test cavity 4 is kept stable, the upper cover of the pressure test cavity 4 is covered, and the pressure test cavity is installed in a sealing way;
Step four: filling the pressure test cavity 4 with a gas medium;
Step five: adjusting the pressure control system 6 to enable the pressure in the pressure measurement cavity 4 to be static initial pressure; if the dynamic micro pressure is required to be measured, the vibrating table 1 is opened to generate excitation, so that the pressure change is generated in the volume-changing mechanism 3, and the dynamic micro pressure is generated in the pressure measurement test cavity 4;
step five: the pressure value in the pressure test cavity 4 is judged by the laser interferometer 51 through measuring the optical path difference of the laser emitted and received by the laser probe 52, namely, the micro pressure optical measurement is realized.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Claims (3)
1. A micro-pressure optical calibration device, characterized in that: the device mainly comprises a vibrating table (1), a piston (2), a variable volume mechanism (3), a pressure test cavity (4), a laser interferometry system (5) and a control system (6);
The pressure testing cavity (4) is connected with the volume-changing mechanism (3), the vibrating table (1) is connected with the rod of the piston (2), the rod of the piston (2) penetrates into the volume-changing mechanism (3), the vibrating table (1) moves to drive the volume-changing mechanism (3) to change the volume of the pressure cavity, and meanwhile the pressure in the pressure testing cavity (4) is driven to change;
A laser head (52) of a laser interferometer (51) in the laser interferometry system (5) is fixed on a vibration isolation platform (7), and the vibration isolation platform (7) is in non-contact with the vibration platform (1), the piston (2), the variable-volume mechanism (3) and the pressure test cavity (4);
the pressure test cavity (4) is internally provided with a plurality of high reflection surfaces (41) for realizing multiple reflections of an optical path in the cavity and increasing a laser transmission path;
The side wall of the pressure test cavity (4) is provided with a light through hole (42) for transmitting laser signals and the outside;
The number of high reflection surfaces (41) in the pressure test cavity (4) is two or more, and by setting the positions of the reflection surfaces (41) and adjusting the angle of incident light (54), the increase of the transmission path of laser in the pressure test cavity (4) is realized, and reflected light (55) is returned to a laser head (52) of the laser interferometer (51);
The lower wall of the pressure testing cavity (4) is provided with a mounting interface (43) and a pressure transmission window (44) which are used for being communicated with the tested gas so that the gas pressure in the pressure testing cavity (4) is consistent with the gas pressure in the variable volume mechanism (3);
One or more light-passing holes (42) are formed in the side wall of the pressure testing cavity (4), and a reflecting mirror (53) is arranged outside the holes to reflect laser back into the pressure testing cavity (4);
The pressure regulating mechanism (61) is connected with the air source (62) and the vacuum pump (63) and is used for controlling the initial pressure of the pressure testing cavity (4).
2. A micro-pressure optical calibration apparatus according to claim 1, wherein: the volume-changing mechanism (3) adopts a cylindrical structure, and the relation between the internal generated pressure p (t) and the vibration displacement x (t) is as follows:
Wherein L 0 is the equivalent length, and the calculation formula is as follows: D 0 is the internal diameter of the variable volume mechanism (3), V 0 is the initial volume of the variable volume mechanism (3), P s is the initial pressure, and γ is the specific heat ratio of the medium.
3. A micro-pressure optical measurement method, based on a micro-pressure optical calibration device according to claim 1 or 2, characterized in that: the method comprises the following steps:
Step one: opening an upper cover of the pressure testing cavity (4), opening the laser interferometer (51), and enabling laser to enter the pressure testing cavity (4) through adjusting the incidence position and angle of the laser and return to a laser head (52) of the laser interferometer (51) after multiple reflections; by changing the incidence position and angle of the laser head (52), the change of different laser transmission paths in the pressure test cavity (4) is realized;
Step two: covering an upper cover of the pressure testing cavity (4), and sealing and installing;
Step three: filling the pressure test cavity (4) with a gas medium;
Step four: the pressure control system (6) is regulated to enable the pressure in the pressure test cavity (4) to be static initial pressure; if the dynamic micro pressure is required to be measured, the vibrating table (1) is opened to generate excitation, so that the pressure change is generated in the volume-changing mechanism (3), and the dynamic micro pressure is generated in the pressure testing cavity (4);
step five: and acquiring and processing an optical path change signal measured by a laser interferometer (51) to obtain a micro pressure value of the pressure test cavity (4), namely realizing micro pressure optical measurement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111349631.0A CN114112172B (en) | 2021-11-15 | 2021-11-15 | Micro pressure optical measurement method and calibration device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111349631.0A CN114112172B (en) | 2021-11-15 | 2021-11-15 | Micro pressure optical measurement method and calibration device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114112172A CN114112172A (en) | 2022-03-01 |
| CN114112172B true CN114112172B (en) | 2024-06-04 |
Family
ID=80395602
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111349631.0A Active CN114112172B (en) | 2021-11-15 | 2021-11-15 | Micro pressure optical measurement method and calibration device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114112172B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4322979A (en) * | 1979-09-17 | 1982-04-06 | Siemens Aktiengesellschaft | Optical device for measuring slight differences of pressure by means of a change in light intensity |
| JP2876528B1 (en) * | 1998-01-14 | 1999-03-31 | 科学技術庁防災科学技術研究所長 | Pressure change measuring device |
| CN2420635Y (en) * | 2000-05-11 | 2001-02-21 | 中国科学院长春光学精密机械与物理研究所 | High precision monitor for coherent laser gas pressure change |
| CN101655404A (en) * | 2009-09-17 | 2010-02-24 | 上海华魏光纤传感技术有限公司 | Optical hydraulic detection device and method |
| CN110926668A (en) * | 2019-12-24 | 2020-03-27 | 中国科学院微电子研究所 | Pressure sensor for improving measurement accuracy by utilizing total reflection principle and application thereof |
| CN110926683A (en) * | 2019-11-29 | 2020-03-27 | 中国科学院微电子研究所 | Pressure sensor based on laser reflection principle and pressure sensing method thereof |
-
2021
- 2021-11-15 CN CN202111349631.0A patent/CN114112172B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4322979A (en) * | 1979-09-17 | 1982-04-06 | Siemens Aktiengesellschaft | Optical device for measuring slight differences of pressure by means of a change in light intensity |
| JP2876528B1 (en) * | 1998-01-14 | 1999-03-31 | 科学技術庁防災科学技術研究所長 | Pressure change measuring device |
| CN2420635Y (en) * | 2000-05-11 | 2001-02-21 | 中国科学院长春光学精密机械与物理研究所 | High precision monitor for coherent laser gas pressure change |
| CN101655404A (en) * | 2009-09-17 | 2010-02-24 | 上海华魏光纤传感技术有限公司 | Optical hydraulic detection device and method |
| CN110926683A (en) * | 2019-11-29 | 2020-03-27 | 中国科学院微电子研究所 | Pressure sensor based on laser reflection principle and pressure sensing method thereof |
| CN110926668A (en) * | 2019-12-24 | 2020-03-27 | 中国科学院微电子研究所 | Pressure sensor for improving measurement accuracy by utilizing total reflection principle and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114112172A (en) | 2022-03-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5414509A (en) | Optical pressure/density measuring means | |
| CN204064535U (en) | Pressure transducer | |
| CN103697954B (en) | A kind of microcavity interference flow velocity pressure reduction sensitive structure and microcavity interference flow velocity of optical flow transducer | |
| CN102589439B (en) | Contact type temperature non-inductive three-dimensional detection sensor based on fiber Bragg grating (FBG) | |
| CN103954589B (en) | The precision measurement apparatus of a kind of optical material specific refractory power and method | |
| CN106153249B (en) | One kind can trace to the source liquid sinusoidal pressure calibrating installation | |
| CN108195555A (en) | Optical fibre balance aerodynamics force measurement system and measuring method | |
| CN106940220B (en) | A kind of laser wavelength real-time measurement device of Simple low-cost | |
| CN104807781B (en) | A kind of measuring device of refraction index of air and measuring method based on dispersion interferometric method | |
| CN100549615C (en) | Measure the optics of optical transparent body and the method for physical thickness | |
| CN115046724B (en) | Highly integrated wide-angle optical fiber pneumatic probe | |
| CN108956534A (en) | A kind of refractive index measurement method based on open cavity Fabry Parot interferometer | |
| CN108663158B (en) | Push-pull type optical fiber differential pressure sensor | |
| CN109375124B (en) | Magnetic field vector sensor based on large-angle inclined fiber bragg grating | |
| CN114112172B (en) | Micro pressure optical measurement method and calibration device | |
| CN103033307B (en) | Light interference based air pressure distribution measuring method | |
| Ding et al. | A low-flow fiber-optic flowmeter based on bending measuring using a cladding fiber Bragg grating | |
| CN204043623U (en) | Apparatus for measuring thickness of thin film | |
| CN110926668A (en) | Pressure sensor for improving measurement accuracy by utilizing total reflection principle and application thereof | |
| CN113494890B (en) | Fiber bragg grating strain sensor precision measuring device and method based on FPI interferometer | |
| CN212007108U (en) | Steel surface coating thickness measuring device based on optical fiber simply supported beam structure | |
| Butler et al. | Effect of Varying Beam Diameter on Global Jitter of Laser Beam Passing Through Turbulent Flows | |
| CN107490395A (en) | A kind of chamber grows controllable optical fiber Fabry Perot chamber constructive methods | |
| RU58216U1 (en) | LASER-INTERFERENCE HYDROPHONE | |
| CN104596635A (en) | Differential vibration acceleration sensor based on segmental PSD (Power Spectral Density) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |