CN113701647A - Steel surface coating thickness measuring device based on optical fiber simply supported beam structure - Google Patents
Steel surface coating thickness measuring device based on optical fiber simply supported beam structure Download PDFInfo
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- CN113701647A CN113701647A CN202010440501.7A CN202010440501A CN113701647A CN 113701647 A CN113701647 A CN 113701647A CN 202010440501 A CN202010440501 A CN 202010440501A CN 113701647 A CN113701647 A CN 113701647A
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- optical fiber
- coating
- beam structure
- coating thickness
- simply supported
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- 239000013307 optical fiber Substances 0.000 title claims abstract description 70
- 239000011248 coating agent Substances 0.000 title claims abstract description 51
- 238000000576 coating method Methods 0.000 title claims abstract description 51
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 25
- 239000010959 steel Substances 0.000 title claims abstract description 25
- 239000000919 ceramic Substances 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 3
- 239000004205 dimethyl polysiloxane Substances 0.000 claims description 3
- 235000013870 dimethyl polysiloxane Nutrition 0.000 claims description 3
- CXQXSVUQTKDNFP-UHFFFAOYSA-N octamethyltrisiloxane Chemical compound C[Si](C)(C)O[Si](C)(C)O[Si](C)(C)C CXQXSVUQTKDNFP-UHFFFAOYSA-N 0.000 claims description 3
- 238000004987 plasma desorption mass spectroscopy Methods 0.000 claims description 3
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- 230000008859 change Effects 0.000 abstract description 12
- 238000005259 measurement Methods 0.000 abstract description 7
- 238000009675 coating thickness measurement Methods 0.000 abstract description 4
- 230000007547 defect Effects 0.000 abstract description 4
- 238000012544 monitoring process Methods 0.000 abstract 1
- 230000003287 optical effect Effects 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 3
- 230000003595 spectral effect Effects 0.000 description 3
- 230000002238 attenuated effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
- G01B11/06—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material
- G01B11/0616—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material of coating
- G01B11/0675—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material of coating using interferometry
Abstract
The invention discloses a steel surface coating thickness measuring device based on an optical fiber simply supported beam structure, which comprises a laser, an optical fiber circulator, an optical fiber coating thickness measuring sensing head, a photoelectric detector and a central control unit; when the optical fiber coating thickness measurement sensing head is vertically attached to the surface of the steel to be measured, single-frequency ultrasonic waves emitted by PZT are reflected twice on the upper surface and the lower surface of the coating to be measured to obtain two paths of ultrasonic waves with different sound pressures, so that the output light intensity of an F-P cavity interference sensor formed based on an optical fiber simply supported beam structure is changed, and the coating thickness can be reversely deduced by monitoring the change of the light intensity through a photoelectric detector; the invention has the advantages that: the characteristics of high precision and strong ultrasonic wave penetrability of the optical fiber interference sensor are utilized, and the defects that the traditional thickness measurement is low in precision and the optical fiber sensor cannot be used for measuring the thickness of the non-transparent coating are overcome.
Description
Technical Field
The invention belongs to the technical field of optical fiber sensing and the field of coating thickness measurement, and particularly relates to a steel surface coating thickness measuring device based on an optical fiber simply supported beam structure.
Background
The coating on the steel surface has various functions, such as fire prevention, corrosion resistance and the like, the coating performance of the steel surface is improved along with the increase of the thickness of the coating, but the coating performance of the steel surface is not in an absolute linear relation with the coating performance of the steel surface, a limit value exists, the performance of the steel structure is almost kept unchanged when the coating thickness is increased, and the protective effect cannot be achieved when the thickness is too small, so that the measurement of the coating thickness of the steel surface plays a crucial role in improving the overall performance of the steel structure.
The traditional coating thickness gauge mainly adopts electronic measurement modes such as ultrasonic wave, magnetism, eddy current and the like for measuring the thickness of a workpiece coating, and the devices have the defects of complex structure, low measurement precision, weak anti-electromagnetic interference, small measurement range and the like. With the rapid development of the optical fiber sensing technology, the optical fiber F-P sensor based on the interference principle has high attention on the aspect of coating thickness measurement due to the advantages of small volume, high precision, high response speed and the like.
Disclosure of Invention
Aiming at the defects of the traditional steel surface thickness measurement and the advantages of an optical fiber F-P structure, the invention provides a steel surface coating thickness measuring device based on an optical fiber simple beam structure.
The invention is realized by the following technical scheme:
a steel surface coating thickness measuring device based on an optical fiber simply supported beam structure is composed of a laser (1), a central control unit (2), an optical fiber circulator (3), a photoelectric detector (4) and an optical fiber coating thickness measuring sensing head (5); the method is characterized in that: the optical fiber coating thickness measuring sensing head (5) comprises an ultrasonic generator (6) and an optical fiber F-P sensor (7); the output end of the laser (1) is connected with the input end of the optical fiber circulator (3), the first output end of the optical fiber circulator (3) is connected with the input end of the optical fiber coating thickness measuring sensing head (5), the second output end of the optical fiber circulator (3) is connected with the input end of the photoelectric detector (4), and the output end of the photoelectric detector (4) is connected with the input end of the central control unit (2).
An ultrasonic generator (6) in the optical fiber coating thickness measurement sensing head (5) is parallel to an optical fiber F-P sensor (7), and the end faces of the ultrasonic generator and the optical fiber F-P sensor are in the same horizontal plane.
The optical fiber F-P sensor (7) is used as an ultrasonic receiving device and comprises a single-mode optical fiber (7-1), a ceramic ferrule (7-2) and an elastic film (7-3), wherein the thickness of the elastic film (7-3) is not more than 0.13 mu m, and two ends of the elastic film are fixed on the ceramic ferrule (7-2) to form a simple beam structure.
The ultrasonic generator (6) emits single-frequency longitudinal waves, the frequency of the emitted ultrasonic waves is determined by the properties of the coating material of the tested piece, and the ultrasonic frequency can be adjusted according to the tested piece.
The elastic film (7-3) of the optical fiber F-P sensor (7) is a film with low Young modulus, such as a PDMS film or a silicon film.
The working principle of the invention is as follows:
when ultrasonic waves propagate in a measured coating on the surface of steel, the energy of the ultrasonic waves is attenuated due to diffusion, absorption and scattering and the like, and the variation quantity delta P of the sound pressure can be expressed as follows:
in the formula: phIs the sound pressure at 2h from the sound source, P0The initial sound pressure, α, attenuation coefficient, and h, coating thickness.
When the ultrasonic wave attenuated by the coating acts on the optical fiber F-P sensor, the simply supported beam structure diaphragm deforms under the action of the ultrasonic sound pressure, and the relation between the deformation quantity delta and the sound pressure variation quantity delta P is expressed as follows:
in the formula: wherein t is the film thickness, E is the Young's modulus of the film material, a is the length of the short side of the rectangle, and σ0For initial pre-stress, v is the poisson's ratio and δ is the central deformation.
The deformation of the simply supported beam structure diaphragm causes the cavity length of the optical fiber F-P sensor to change correspondingly, so that the optical fiber F-P cavity outputs the spectral intensity IRChanges occur, represented as:
wherein
In the formula: r is the reflectivity, λ is the wavelength of the incident light, I0In order to be the intensity of the incident light,
is an optical phase, n0Is the refractive index of the medium within the cavity and L is the F-P cavity length.
Output spectral intensity I of optical fiber F-P sensorRAfter entering the photoelectric detector, the change is converted into an output electric signal U of the photoelectric detectoroThe expression of (a) is as follows:
Uo＝S·IR·Rload (6)
in the formula: s is the photoelectric sensitivity, RloadIs the equivalent load of the photodetector.
From the formula (6), the output voltage change Δ U of the photodetector can be known0Proportional to the fluctuation Delta I of the output spectral intensity of the F-P sensorRThe fluctuation of the thickness of the coating is caused by the deformation delta of the film of the simply supported beam structure brought by the change delta P of the ultrasonic sound pressure, and the thickness h of the measured coating is the root of the change of the ultrasonic sound pressure, so that the thickness of the coating on the surface of the measured steel can be reversely deduced by measuring the change of the output voltage of the photoelectric detector.
The invention has the beneficial effects that:
the invention designs the elastic film of the optical fiber F-P sensor into a simple beam structure, can sense the change of ultrasonic waves with high sensitivity when receiving the ultrasonic waves reflected by the coating and convert the change into the change of optical signals output by the optical fiber F-P sensor, and the change of the optical signals is converted into the change of electric signals by the photoelectric detector and calculated by the central control unit. The coating thickness measuring device is simple in structure, convenient to operate and high in precision, avoids the defects of low precision, weak anti-electromagnetic interference capability and the like of traditional equipment, and has a good application prospect.
Drawings
FIG. 1 is a schematic structural diagram of a steel surface coating thickness measuring device based on an optical fiber simply supported beam structure.
Fig. 2 is a schematic structural diagram of a fiber coating thickness measuring sensor head.
FIG. 3 is a front and side view of a fiber optic F-P sensor.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
As shown in fig. 1, a steel surface coating thickness measuring device based on an optical fiber simple supported beam structure is composed of a laser (1), a central control unit (2), an optical fiber circulator (3), a photoelectric detector (4) and an optical fiber coating thickness measuring sensing head (5); the method is characterized in that: the optical fiber coating thickness measuring sensing head (5) comprises an ultrasonic generator (6) and an optical fiber F-P sensor (7); the output end of the laser (1) is connected with the input end of the optical fiber circulator (3), the first output end of the optical fiber circulator (3) is connected with the input end of the optical fiber coating thickness measuring sensing head (5), the second output end of the optical fiber circulator (3) is connected with the input end of the photoelectric detector (4), and the output end of the photoelectric detector (4) is connected with the input end of the central control unit (2). The ultrasonic generator (6) in the optical fiber coating thickness measuring sensing head (5) is parallel to the optical fiber F-P sensor (7), and the end faces are in the same horizontal plane. The optical fiber-P sensing head (7) is used as an ultrasonic receiving device and comprises a single-mode optical fiber (7-1), a ceramic ferrule (7-2) and an elastic film (7-3), wherein the thickness of the elastic film (7-3) is not more than 0.13 mu m, and two ends of the elastic film are fixed on the ceramic ferrule (7-2) to form a simple beam structure. The ultrasonic generator (6) emits single-frequency longitudinal waves, the frequency of the emitted ultrasonic waves is determined by the properties of the coating material of the tested piece, and the ultrasonic frequency can be adjusted according to the tested piece. The elastic film (7-3) of the optical fiber F-P sensor (7) is a film with low Young's modulus, such as a PDMS film or a silicon film.
According to the method, one end face of the optical fiber F-P sensor is designed into a simple beam structure based on an elastic film, namely the end face of the ceramic ferrule is incompletely sealed to form an open cavity, so that the response sensitivity of the F-P sensor is effectively improved, the ultrasonic loss caused by the thickness of the steel surface coating can be sensed quickly and accurately, and the high-accuracy quick measurement of the coating thickness is realized.
Claims (5)
1. A steel surface coating thickness measuring device based on an optical fiber simply supported beam structure is composed of a laser (1), a central control unit (2), an optical fiber circulator (3), a photoelectric detector (4) and an optical fiber coating thickness measuring sensing head (5); the method is characterized in that: the optical fiber coating thickness measuring sensing head (5) comprises an ultrasonic generator (6) and an optical fiber F-P sensor (7); the output end of the laser (1) is connected with the input end of the optical fiber circulator (3), the first output end of the optical fiber circulator (3) is connected with the input end of the optical fiber coating thickness measuring sensing head (5), the second output end of the optical fiber circulator (3) is connected with the input end of the photoelectric detector (4), and the output end of the photoelectric detector (4) is connected with the input end of the central control unit (2).
2. The device for measuring the thickness of the coating on the steel surface based on the optical fiber simply supported beam structure as claimed in claim 1, wherein: an ultrasonic generator (6) in the optical fiber coating thickness measuring sensing head (5) is parallel to an optical fiber F-P sensor (7), and the end faces of the ultrasonic generator and the optical fiber F-P sensor are in the same horizontal plane.
3. The device for measuring the thickness of the coating on the steel surface based on the optical fiber simply supported beam structure as claimed in claim 1, wherein: the optical fiber F-P sensor (7) is used as a receiving device of ultrasonic waves and comprises a single-mode optical fiber (7-1), a ceramic ferrule (7-2) and an elastic film (7-3), wherein the thickness of the elastic film (7-3) is not more than 0.13 mu m, and two ends of the elastic film are fixed on the ceramic ferrule (7-2) to form a simple beam structure.
4. The device for measuring the thickness of the coating on the steel surface based on the optical fiber simply supported beam structure as claimed in claim 1, wherein: the ultrasonic generator (6) emits single-frequency longitudinal waves, the frequency of the emitted ultrasonic waves is determined by the properties of the coating material of the tested piece, and the ultrasonic frequency can be adjusted according to the tested piece.
5. The device for measuring the thickness of the coating on the steel surface based on the optical fiber simply supported beam structure as claimed in claim 1, wherein: the elastic film (7-3) of the optical fiber F-P sensor (7) is a film with low Young modulus, such as a PDMS film or a silicon film.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010440501.7A CN113701647A (en) | 2020-05-22 | 2020-05-22 | Steel surface coating thickness measuring device based on optical fiber simply supported beam structure |
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| CN202010440501.7A CN113701647A (en) | 2020-05-22 | 2020-05-22 | Steel surface coating thickness measuring device based on optical fiber simply supported beam structure |
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Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101135577A (en) * | 2007-09-29 | 2008-03-05 | 中国科学院上海光学精密机械研究所 | Automatic tuning control F-P fiber optic sensor |
| CN103487129A (en) * | 2013-01-18 | 2014-01-01 | 上海大学 | Point contact type ultrasonic wave sensor |
| CN103557929A (en) * | 2013-11-14 | 2014-02-05 | 北京航空航天大学 | Optical fiber Fabry-Perot sound pressure sensor manufacturing method based on graphene membrane and measuring method and device thereof |
| CN103940352A (en) * | 2014-04-25 | 2014-07-23 | 广州飞拓优视光电科技有限公司 | Ultra-high-precision freezing detecting device and real-time freezing thickness detecting method thereof |
| CN104990521A (en) * | 2015-06-23 | 2015-10-21 | 烟台富润实业有限公司 | Non-contact type composite material thickness measurement device and method |
| CN107907203A (en) * | 2017-11-30 | 2018-04-13 | 大连理工大学 | A kind of demodulation method of optical fiber F P cavate sonic sensors |
| CN108871419A (en) * | 2018-04-20 | 2018-11-23 | 南京航空航天大学 | More physical quantity optical fiber sensing systems, the control of its feedback loop and its detection method |
| CN109029687A (en) * | 2018-07-16 | 2018-12-18 | 华中科技大学 | A kind of fiber optic acoustic sensors |
| CN109655176A (en) * | 2019-01-25 | 2019-04-19 | 东北大学 | A kind of high-precision temperature probe based on cavity filled-type microstructured optical fibers interferometer |
| CN109799435A (en) * | 2019-03-05 | 2019-05-24 | 重庆大学 | A kind of local discharge sensor combining graphene diaphragm and micro optical fiber interference cavity and the detection method based on this |
| CN109855662A (en) * | 2019-02-28 | 2019-06-07 | 武汉理工大学 | The method and device of the quasi-distributed many reference amounts measurement of fiber Bragg grating F-P chamber array |
| CN111112035A (en) * | 2019-12-25 | 2020-05-08 | 华中科技大学 | Transmit-receive integrated all-optical ultrasonic transducer device and preparation method thereof |
| CN111458669A (en) * | 2020-06-08 | 2020-07-28 | 中国计量大学 | Optical fiber magnetic field and temperature sensing probe based on double F-P structure |
| CN212007108U (en) * | 2020-05-22 | 2020-11-24 | 浙江中能工程检测有限公司 | Steel surface coating thickness measuring device based on optical fiber simply supported beam structure |
| CN113701653A (en) * | 2020-05-22 | 2021-11-26 | 浙江中能工程检测有限公司 | Nano-particle-doped PDMS flexible sensor for bridge large strain measurement |
-
2020
- 2020-05-22 CN CN202010440501.7A patent/CN113701647A/en active Pending
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101135577A (en) * | 2007-09-29 | 2008-03-05 | 中国科学院上海光学精密机械研究所 | Automatic tuning control F-P fiber optic sensor |
| CN103487129A (en) * | 2013-01-18 | 2014-01-01 | 上海大学 | Point contact type ultrasonic wave sensor |
| CN103557929A (en) * | 2013-11-14 | 2014-02-05 | 北京航空航天大学 | Optical fiber Fabry-Perot sound pressure sensor manufacturing method based on graphene membrane and measuring method and device thereof |
| CN103940352A (en) * | 2014-04-25 | 2014-07-23 | 广州飞拓优视光电科技有限公司 | Ultra-high-precision freezing detecting device and real-time freezing thickness detecting method thereof |
| CN104990521A (en) * | 2015-06-23 | 2015-10-21 | 烟台富润实业有限公司 | Non-contact type composite material thickness measurement device and method |
| CN107907203A (en) * | 2017-11-30 | 2018-04-13 | 大连理工大学 | A kind of demodulation method of optical fiber F P cavate sonic sensors |
| CN108871419A (en) * | 2018-04-20 | 2018-11-23 | 南京航空航天大学 | More physical quantity optical fiber sensing systems, the control of its feedback loop and its detection method |
| CN109029687A (en) * | 2018-07-16 | 2018-12-18 | 华中科技大学 | A kind of fiber optic acoustic sensors |
| CN109655176A (en) * | 2019-01-25 | 2019-04-19 | 东北大学 | A kind of high-precision temperature probe based on cavity filled-type microstructured optical fibers interferometer |
| CN109855662A (en) * | 2019-02-28 | 2019-06-07 | 武汉理工大学 | The method and device of the quasi-distributed many reference amounts measurement of fiber Bragg grating F-P chamber array |
| CN109799435A (en) * | 2019-03-05 | 2019-05-24 | 重庆大学 | A kind of local discharge sensor combining graphene diaphragm and micro optical fiber interference cavity and the detection method based on this |
| CN111112035A (en) * | 2019-12-25 | 2020-05-08 | 华中科技大学 | Transmit-receive integrated all-optical ultrasonic transducer device and preparation method thereof |
| CN212007108U (en) * | 2020-05-22 | 2020-11-24 | 浙江中能工程检测有限公司 | Steel surface coating thickness measuring device based on optical fiber simply supported beam structure |
| CN113701653A (en) * | 2020-05-22 | 2021-11-26 | 浙江中能工程检测有限公司 | Nano-particle-doped PDMS flexible sensor for bridge large strain measurement |
| CN111458669A (en) * | 2020-06-08 | 2020-07-28 | 中国计量大学 | Optical fiber magnetic field and temperature sensing probe based on double F-P structure |
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