CN109839514B - High-precision optical accelerometer with self-zero-adjusting function - Google Patents
High-precision optical accelerometer with self-zero-adjusting function Download PDFInfo
- Publication number
- CN109839514B CN109839514B CN201910209227.XA CN201910209227A CN109839514B CN 109839514 B CN109839514 B CN 109839514B CN 201910209227 A CN201910209227 A CN 201910209227A CN 109839514 B CN109839514 B CN 109839514B
- Authority
- CN
- China
- Prior art keywords
- beryllium copper
- outer ring
- ring
- plane reflector
- cmos sensor
- 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
Images
Landscapes
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The invention discloses a high-precision accelerometer with a self-zero-adjusting function, which consists of a vibration pickup unit and a sensing unit; the vibration pickup unit is formed by stringing at least two beryllium copper reeds by utilizing a central fixing plate and an outer ring pressure ring to form a vertical elastic support, and is fixedly installed on an annular top cover by utilizing the outer ring pressure ring, a mass block is fixedly arranged at the central position of the lower surface of the bottom beryllium copper reed, and a first plane reflector is arranged on the bottom surface of the mass block; emergent light of the laser in the sensing unit is reflected by the second plane reflector and the first plane reflector in sequence and then is incident to a photosensitive surface of the CMOS sensor; and taking the output signal of the CMOS sensor as the detection output signal of the accelerometer. The invention can realize high-sensitivity low-frequency vibration detection and has the advantages of convenient adjustment, low cost, strong adaptability and the like.
Description
Technical Field
The invention relates to the field of vibration detection, in particular to a high-precision optical accelerometer with a self-zeroing function, which can be applied to micro-vibration detection.
Background
The precise measuring instruments including the micro-nano three-coordinate measuring machine, the atomic force microscope, the high-precision laser interferometer and the like can be influenced by external interference in work, and micro vibration is one of main interference factors. For example, small vibrations caused by road traffic, people walking, sounds, etc. can interfere with the use of precision instruments. Therefore, a high-precision micro-vibration measurement system needs to be developed to realize active vibration isolation, the resolution of the amplitude detected by the system needs to reach the micron level, and real-time high-precision measurement can be carried out.
The accelerometer in the prior art, such as a PZT accelerometer, has low sensitivity, and the sensitivity is generally at the level of mV/g; strain accelerometers are not suitable for precision measurement due to temperature drift; the detection precision of the FBG accelerometer depends on the modulation and demodulation precision of the FBG accelerometer, and the cost for achieving high precision is high; the MEMS accelerometer needs to adopt a micro-processing technology, which is costly to process, and the output signal of the MEMS accelerometer is weak. These accelerometers do not meet the need for detection of minute vibrations.
Disclosure of Invention
The invention aims to avoid the defects of the prior art, provides the high-precision optical accelerometer with the self-zeroing function, which can be applied to micro-vibration detection so as to obtain the high-precision micro-vibration detection and further realize the precise inhibition of low-frequency micro-vibration, and has the advantages of strong adaptability, strong refitability, low cost, no adjustment, convenient assembly and adjustment and the like.
The invention adopts the following technical scheme for solving the technical problems:
the invention has the high-precision accelerometer of the function of self-zeroing, the characteristic is formed by picking up unit and sensing unit;
the vibration pickup unit is characterized in that at least two beryllium copper spring pieces are arranged into a vertical elastic support in a string mode by utilizing a central fixing plate and an outer ring pressure ring, the vertical elastic support is fixedly arranged on an annular top cover by utilizing the outer ring pressure ring, a mass block is fixedly arranged at the central position of the lower surface of the beryllium copper spring piece at the bottom, and a first plane reflector is arranged on the bottom surface of the mass block;
the sensing unit is characterized in that a detector cavity is formed by a bottom plate and a supporting side plate standing on the bottom plate, and a laser, a CMOS sensor and a second plane reflector are respectively arranged in the detector cavity; the annular top cover is fixedly arranged at the top of the supporting side plate, a first plane reflector in the vibration pickup unit is positioned on the top surface of the detection cavity, and the reflecting surface of the first plane reflector is horizontally downward; emergent light of the laser is reflected by the second plane reflector and the first plane reflector in sequence and then is incident on a photosensitive surface of the CMOS sensor; and taking the output signal of the CMOS sensor as the detection output signal of the accelerometer.
The high-precision accelerometer with the self-zeroing function is also characterized in that: the beryllium copper reed is in a double-ring cross symmetrical configuration and is provided with a central disc, an inner ring and an outer ring, the central disc is connected with the inner ring through four inner-path elastic beams in cross distribution, the inner ring is connected with the outer ring through four outer-path elastic beams in cross distribution, and the inner-path elastic beams and the outer-path elastic beams are arranged in a staggered manner; the central fixing plate and the mass block are positioned at the position of the central disc, and the outer ring pressing ring is positioned at the position of the outer ring of the beryllium copper reed.
The high-precision accelerometer with the self-zeroing function is also characterized in that:
two beryllium copper reeds, namely a first beryllium copper reed and a second beryllium copper reed, are arranged in the vibration pickup unit;
the inner ring of the vibration pickup unit is sequentially as follows from top to bottom: the first center fixing plate, the center disc of the first beryllium copper reed, the second center fixing plate, the center disc of the second beryllium copper reed, the mass block and the first plane mirror are fixed by screws along the axial direction;
the outer ring of the vibration pickup unit is sequentially as follows from top to bottom: the first pressing ring, the outer ring of the first beryllium copper reed, the second pressing ring and the outer ring of the second beryllium copper reed are fixed by screws along the axial direction.
The high-precision accelerometer with the self-zeroing function is also characterized in that: emergent light of the laser in the sensing unit is incident to the second plane reflector at an angle of 45 degrees, reflected light reflected by the second plane reflector is also incident to the first plane reflector at an angle of 45 degrees, and the reflected light reflected by the first plane reflector is vertically incident to a light sensing surface of the CMOS sensor.
The high-precision accelerometer with the self-zeroing function is also characterized in that: the CMOS sensor comprises a sensor body and a light-sensitive surface; when the light spot initially incident on the photosensitive surface is deviated due to the influence of external temperature change or other factors, the current position of the light spot on the photosensitive surface is determined according to the output signal of the CMOS sensor, and the current position of the light spot is used as a coordinate zero point for data processing, so that the self-zeroing function is realized.
The high-precision accelerometer with the self-zeroing function is also characterized in that: the vibration pickup unit realizes different frequency detection ranges and widens the application range of the vibration pickup unit by replacing beryllium copper reeds with different thicknesses and mass blocks with different masses.
The high-precision accelerometer with the self-zeroing function is also characterized in that: the CMOS sensor is replaced with a quadrant photo-sensor QPD or a position sensitive detector PSD.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention can realize the detection of micro vibration;
2. according to the invention, the double beryllium copper reeds are adopted to form the vertical elastic support, so that the horizontal swinging of the mass block can be effectively inhibited, and the detection precision of the accelerometer is effectively improved;
3. the CMOS sensor is adopted as a sensing device, so that the optical path is simple, and the detection precision is high;
4. the invention adopts the CMOS sensor as a sensing device, and can realize automatic zero setting through the post-processing system, so that a zero setting mechanism is not required to be arranged, and the stability of the accelerometer is improved.
Drawings
FIG. 1 is a schematic view of the present invention;
FIG. 2 is a schematic view of the internal structure of the present invention;
FIG. 3 is a schematic view of a vibration pickup assembly according to the present invention;
FIG. 4 is an exploded view of a vibration pickup assembly according to the present invention;
FIG. 5 is a schematic view of the shape of the reed of the present invention;
FIG. 6 is a schematic diagram of a CMOS sensor according to the present invention;
FIG. 7 is a schematic diagram of the self-zeroing function of the CMOS sensor of the present invention;
FIG. 8 is a schematic view of the optical path in the present invention;
reference numbers in the figures: the optical fiber sensing device comprises a vibration pickup unit 1, a first center fixing plate 1a, a first press ring 1b, a first beryllium copper reed 1c, a second center fixing plate 1d, a second press ring 1e, a second beryllium copper reed 1f, a mass block 1g, a first plane mirror 1h, an annular top cover 2, a sensing unit 3, a supporting side plate 4, a CMOS sensor 5, a photosensitive surface 5b, a light spot 5c, a bottom plate 6, a second plane mirror 7, a laser 8, a central disc 11, an inner ring 12, an outer ring 13, an inner elastic beam 14 and an outer elastic beam 15.
Detailed Description
Referring to fig. 1 and 2, the high-precision accelerometer with the self-zeroing function in the present embodiment is composed of a vibration pickup unit 1 and a sensing unit 3.
As shown in fig. 3 and 4, the vibration pickup unit 1 is provided with at least two beryllium copper reeds which are strung by using a central fixing plate and an outer ring compression ring to form a vertical elastic support, the vertical elastic support is fixedly arranged on an annular top cover 2 by using the outer ring compression ring, a mass block 1g is fixedly arranged at the central position of the lower surface of the bottom beryllium copper reed, and a first plane mirror 1h is arranged on the bottom surface of the mass block 1 g;
as shown in fig. 2, the sensing unit 3 is a detector cavity formed by a bottom plate 6 and a supporting side plate 4 standing on the bottom plate 6, and a laser 8, a CMOS sensor 5 and a second plane mirror 7 are respectively arranged in the detector cavity; the annular top cover 2 is fixedly arranged at the top of the supporting side plate 4, a first plane reflector 1h in the vibration pickup unit 1 is positioned on the top surface of the detection cavity, and the reflecting surface of the first plane reflector is horizontally downward; emergent light of the laser 8 is reflected by the second plane reflector and the first plane reflector in sequence and then is incident on a light-sensitive surface 5b of the CMOS sensor 5; the output signal of the CMOS sensor 5 is used as the detection output signal of the accelerometer.
In specific implementation, as shown in fig. 4 and 5, the beryllium copper spring plate adopts a double-ring cross-symmetric configuration, and has a central disc 11, an inner ring 12 and an outer ring 13, four inner elastic beams 14 distributed in a cross shape are connected between the central disc 11 and the inner ring 12, four outer elastic beams 15 distributed in a cross shape are connected between the inner ring 12 and the outer ring 13, and the inner elastic beams 14 and the outer elastic beams 15 are arranged in a staggered manner; the central fixing plate and the mass block are positioned at the position of the central disc 11, and the outer ring pressing ring is positioned at the position of the outer ring of the beryllium copper reed.
In the embodiment, two beryllium copper reeds, namely a first beryllium copper reed 1c and a second beryllium copper reed 1f, are arranged on the vibration pickup unit; the inner ring of the vibration pickup unit 1 is sequentially as follows from top to bottom: a first central fixing plate 1a, a central disc of a first beryllium copper reed 1c, a second central fixing plate 1d, a central disc of a second beryllium copper reed 1f, a mass block 1g and a first plane mirror 1h which are fixed by screws along the axial direction; the outer ring of the vibration pickup unit 1 is sequentially as follows from top to bottom: the structure form of the double beryllium copper reeds is arranged on the first pressing ring 1b, the outer ring of the first beryllium copper reed 1c, the second pressing ring 1e and the outer ring of the second beryllium copper reed 1f which are axially fixed by screws, so that the vertical rigidity of the vibration pickup unit is improved, the influence of the horizontal swinging of the mass block is inhibited, and the detection precision of the accelerometer is improved.
Referring to fig. 8, considering sensitivity and processing difficulty of the accelerometer, the outgoing light of the laser 8 in the sensing unit 3 is set to be incident on the second plane mirror 7 at an angle of 45 °, the reflected light reflected by the second plane mirror 7 is also incident on the first plane mirror 1h at an angle of 45 °, and the reflected light reflected by the first plane mirror 1h is perpendicularly incident on the photosensitive surface 5b of the CMOS sensor.
Referring to fig. 6 and 7, in the present embodiment, a CMOS sensor is used as a core sensing element, and for a determined size of a CCD sensitive surface, a suitable light spot diameter can be determined to ensure that a light spot does not run out of the CCD sensitive surface due to drift, and self-calibration zero adjustment is implemented by post-processing software, so that the accelerometer is free from adjustment and reliability of the accelerometer is improved; the CMOS sensor 5 includes a sensor body 5a and a photosensitive surface 5 b; when the light spot 5c initially incident on the light sensing surface 5b is shifted due to the change of the external temperature or the influence of other factors, the current position of the light spot on the light sensing surface 5b is determined according to the output signal of the CMOS sensor 5, and the current position of the light spot is used as a coordinate zero point for data processing, so that the self-zeroing function is realized.
In specific implementation, the vibration pickup unit 3 realizes different frequency detection ranges and widens the application range thereof by replacing beryllium copper reeds with different thicknesses and mass blocks with different masses; the CMOS sensor 5 may also be replaced with a quadrant photo sensor QPD, a position sensitive detector PSD, or other photo sensors, and under the condition that the optical path is not changed, higher detection accuracy or wider acceleration detection can be realized, and the application range thereof is widened.
The types of CMOS sensors selected in this embodiment are: basler acA4600-10uc (Basler Co.), the performance parameters of the CMOS sensor of the Basler acA4600-10uc type are shown in Table 1, and the performance parameters which can be realized by the invention are shown in Table 2.
TABLE 1
| Size of |
1/2.3 cun |
| Horizontal/vertical resolution | 4608×3288 |
| Resolution ratio | 14MP |
| Frame rate | 10fps |
TABLE 2
| Minimum detectable frequency | 0.4Hz |
| Sensitivity of the probe | 17.4V/g |
| Minimum |
3×10-4g |
| Noise equivalent acceleration | 16μg(Hz)-1/2 |
The invention adopts a high-precision CMOS sensor, is matched with a vibration pickup with high sensitivity and high stability, and can realize the detection of the frequency of 0.4Hz and the acceleration of 3 multiplied by 10 by the high-precision external processing circuit based on a DSP chip, an image acquisition card and the self-zeroing data-4g, the sensitivity of the accelerometer is 17.4V/g, and the detection of the micro vibration is accurately realized.
Claims (5)
1. A high-precision accelerometer with a self-zero-adjusting function is characterized by comprising a vibration pickup unit (1) and a sensing unit (3);
the vibration pickup unit (1) is characterized in that at least two beryllium copper reeds are strung by utilizing a central fixing plate and an outer ring compression ring to form a vertical elastic support, the vertical elastic support is fixedly arranged on an annular top cover (2) by utilizing the outer ring compression ring, a mass block (1g) is fixedly arranged at the central position of the lower surface of the bottom beryllium copper reed, and a first plane reflector (1h) is arranged on the bottom surface of the mass block (1 g);
the sensing unit (3) is characterized in that a detector cavity is formed by a bottom plate (6) and a supporting side plate (4) standing on the bottom plate (6), and a laser (8), a CMOS sensor (5) and a second plane mirror (7) are respectively arranged in the detector cavity; the annular top cover (2) is fixedly arranged at the top of the supporting side plate (4), a first plane reflector (1h) in the vibration pickup unit (1) is positioned on the top surface of the detection cavity, and the reflecting surface of the first plane reflector is horizontally downward; emergent light of the laser (8) is reflected by the second plane reflector and the first plane reflector in sequence and then is incident on a light-sensitive surface (5b) of the CMOS sensor (5); the output signal of the CMOS sensor (5) is used as the detection output signal of the accelerometer;
the beryllium copper reed is in a double-ring cross symmetrical configuration and is provided with a central disc, an inner ring and an outer ring, the central disc is connected with the inner ring through four inner-path elastic beams in cross distribution, the inner ring is connected with the outer ring through four outer-path elastic beams in cross distribution, and the inner-path elastic beams and the outer-path elastic beams are arranged in a staggered manner; the central fixing plate and the mass block are positioned at the position of the central disc, and the outer ring pressure ring is positioned at the position of the outer ring of the beryllium copper reed;
two beryllium copper reeds, namely a first beryllium copper reed (1c) and a second beryllium copper reed (1f), are arranged in the vibration pickup unit; the inner ring of the vibration pickup unit (1) sequentially comprises from top to bottom: the device comprises a first central fixing plate (1a), a central disc of a first beryllium copper reed (1c), a second central fixing plate (1d), a central disc of a second beryllium copper reed (1f), a mass block (1g) and a first plane mirror (1h), wherein the first central fixing plate (1a) is axially fixed by a screw; the outer ring of the vibration pickup unit (1) is sequentially from top to bottom: the clamping device comprises a first pressing ring (1b) axially fixed by screws, an outer ring of a first beryllium copper reed (1c), a second pressing ring (1e) and an outer ring of a second beryllium copper reed (1 f).
2. A high precision accelerometer with self zeroing function as claimed in claim 1, wherein: emergent light of the laser (8) in the sensing unit (3) enters the second plane reflector (7) at an angle of 45 degrees, reflected light reflected by the second plane reflector (7) enters the first plane reflector (1h) at an angle of 45 degrees, and the reflected light reflected by the first plane reflector (1h) vertically enters a photosensitive surface (5b) of the CMOS sensor.
3. A high precision accelerometer with self zeroing function as claimed in claim 2, wherein: the CMOS sensor (5) comprises a sensor body (5a) and a light-sensitive surface (5 b); when the light spot (5c) which is initially incident on the light sensing surface (5b) is deviated due to the change of the external temperature, the current position of the light spot on the light sensing surface (5b) is determined according to the output signal of the CMOS sensor (5), and data processing is carried out by taking the current position of the light spot as a coordinate zero point, so that the self-zeroing function is realized.
4. A high precision accelerometer with self zeroing function as claimed in claim 1, wherein: the vibration pickup unit (1) realizes different frequency detection ranges by replacing beryllium copper reeds with different thicknesses and mass blocks with different masses, and widens the application range.
5. A high precision accelerometer with self zeroing function as claimed in claim 1, wherein: -replacing the CMOS sensor (5) with a quadrant photo sensor QPD or a position sensitive detector PSD.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910209227.XA CN109839514B (en) | 2019-03-19 | 2019-03-19 | High-precision optical accelerometer with self-zero-adjusting function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910209227.XA CN109839514B (en) | 2019-03-19 | 2019-03-19 | High-precision optical accelerometer with self-zero-adjusting function |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109839514A CN109839514A (en) | 2019-06-04 |
| CN109839514B true CN109839514B (en) | 2021-01-15 |
Family
ID=66885979
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910209227.XA Active CN109839514B (en) | 2019-03-19 | 2019-03-19 | High-precision optical accelerometer with self-zero-adjusting function |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109839514B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115015578B (en) * | 2022-06-15 | 2023-06-27 | 华中科技大学 | Optical fiber accelerometer probe and system of symmetrical double-reed supporting structure |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5359445A (en) * | 1987-10-30 | 1994-10-25 | Alliedsignal Inc. | Fiber optic sensor |
| CN101285700A (en) * | 2007-04-11 | 2008-10-15 | 中国科学院半导体研究所 | Piston type optical fibre grating sonic device |
| CN101419243A (en) * | 2008-11-28 | 2009-04-29 | 中国地震局工程力学研究所 | Isotropy equilibrium acceleration sensor |
| CN102045037A (en) * | 2011-01-07 | 2011-05-04 | 瑞声声学科技(深圳)有限公司 | Piezoelectric vibrator |
| CN103364068A (en) * | 2012-03-28 | 2013-10-23 | 联想(北京)有限公司 | Vibration measuring device and method |
| CN103925987A (en) * | 2013-09-27 | 2014-07-16 | 安徽省传感器厂 | Inertia moving coil type electric sensor |
| CN105203199A (en) * | 2015-06-30 | 2015-12-30 | 庄重 | Ultra-high sensitivity vibration sensor based on micro-nano scale material optical mechanical and electrical system |
| CN107175194A (en) * | 2017-05-31 | 2017-09-19 | 合肥工业大学 | The one-dimensional micro-nano shake table of closed loop |
| CN108646053A (en) * | 2018-08-13 | 2018-10-12 | 湖南庄耀光电科技有限公司 | A kind of laser accelerometer |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040112135A1 (en) * | 1995-08-15 | 2004-06-17 | Letrondo Norberto P. | Star patterned accelerometer reed |
| US6139507A (en) * | 1996-08-12 | 2000-10-31 | Miomsa Acoustics Inc. | Method and apparatus for measuring acoustic power flow within an ear canal |
| CN101782593A (en) * | 2010-03-01 | 2010-07-21 | 龙兴武 | Double Y-shaped cavity double-frequency laser accelerometer |
| CN204154384U (en) * | 2014-10-23 | 2015-02-11 | 中国南方电网有限责任公司电网技术研究中心 | High voltage electric power equip ment sound intersity measurement probe composite shield cover |
-
2019
- 2019-03-19 CN CN201910209227.XA patent/CN109839514B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5359445A (en) * | 1987-10-30 | 1994-10-25 | Alliedsignal Inc. | Fiber optic sensor |
| CN101285700A (en) * | 2007-04-11 | 2008-10-15 | 中国科学院半导体研究所 | Piston type optical fibre grating sonic device |
| CN101419243A (en) * | 2008-11-28 | 2009-04-29 | 中国地震局工程力学研究所 | Isotropy equilibrium acceleration sensor |
| CN102045037A (en) * | 2011-01-07 | 2011-05-04 | 瑞声声学科技(深圳)有限公司 | Piezoelectric vibrator |
| CN103364068A (en) * | 2012-03-28 | 2013-10-23 | 联想(北京)有限公司 | Vibration measuring device and method |
| CN103925987A (en) * | 2013-09-27 | 2014-07-16 | 安徽省传感器厂 | Inertia moving coil type electric sensor |
| CN105203199A (en) * | 2015-06-30 | 2015-12-30 | 庄重 | Ultra-high sensitivity vibration sensor based on micro-nano scale material optical mechanical and electrical system |
| CN107175194A (en) * | 2017-05-31 | 2017-09-19 | 合肥工业大学 | The one-dimensional micro-nano shake table of closed loop |
| CN108646053A (en) * | 2018-08-13 | 2018-10-12 | 湖南庄耀光电科技有限公司 | A kind of laser accelerometer |
Non-Patent Citations (1)
| Title |
|---|
| 基于DVD 光学读取头的悬臂式低频加速度计;李瑞君 等;《机械工程学报》;20190131;第55卷(第2期);第10-17页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109839514A (en) | 2019-06-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100453967C (en) | Micro-displacement optical test method and device thereof | |
| JPH06509415A (en) | probe | |
| JPH03223609A (en) | Touch probe | |
| CN201104239Y (en) | Lever type micro-displacement optical measuring device | |
| US10288403B2 (en) | Single sensor type three-dimensional micro/nano contact trigger measuring probe | |
| CN109839514B (en) | High-precision optical accelerometer with self-zero-adjusting function | |
| Chu et al. | Development of an optical accelerometer with a DVD pick-up head | |
| US5837998A (en) | Two-dimensional fiber optic acceleration and vibration sensor | |
| JPH0697261B2 (en) | Micro displacement measuring device using semiconductor laser | |
| US4152940A (en) | Vibration detector | |
| Liu et al. | Development of an optical accelerometer for low-frequency vibration using the voice coil on a DVD pickup head | |
| CN109827680B (en) | Three-dimensional high-sensitivity micrometer based on CMOS sensor | |
| CN214224342U (en) | Device for testing micro-vibration of low-temperature cold head of refrigerating machine | |
| CN112781495B (en) | Three-dimensional contact trigger type measuring probe based on suspension laser structure | |
| CN104596635A (en) | Differential vibration acceleration sensor based on segmental PSD (Power Spectral Density) | |
| JPH0450720A (en) | Optical length measuring instrument | |
| CN204359427U (en) | Based on the differential type vibration acceleration sensor of merogenesis PSD | |
| JP3125844B2 (en) | Voltage measuring device | |
| CN210221371U (en) | Micro-pressure measuring device based on Michelson interference principle | |
| CN114812785A (en) | Device for testing micro-vibration of low-temperature cold head of refrigerating machine | |
| TWI260410B (en) | Optical accelerometer | |
| JPS63115017A (en) | Optical vibrometer | |
| SU1696854A1 (en) | Device for object displacement measurement | |
| Zheng et al. | New parallel plate interferometer for measuring angular displacement | |
| SU1379610A1 (en) | Spherometer |
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 |