CN109990834A - High-temperature flight particle temperature, speed, partial size in-situ measuring method - Google Patents
High-temperature flight particle temperature, speed, partial size in-situ measuring method Download PDFInfo
- Publication number
- CN109990834A CN109990834A CN201910240464.2A CN201910240464A CN109990834A CN 109990834 A CN109990834 A CN 109990834A CN 201910240464 A CN201910240464 A CN 201910240464A CN 109990834 A CN109990834 A CN 109990834A
- Authority
- CN
- China
- Prior art keywords
- image
- temperature
- particle
- camera
- particles
- 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.)
- Pending
Links
- 239000002245 particle Substances 0.000 title claims abstract description 218
- 238000000034 method Methods 0.000 title claims abstract description 66
- 238000011065 in-situ storage Methods 0.000 title abstract 2
- 230000003287 optical effect Effects 0.000 claims abstract description 20
- 230000007704 transition Effects 0.000 claims abstract description 8
- 238000005259 measurement Methods 0.000 claims description 47
- 238000005520 cutting process Methods 0.000 claims description 18
- 238000004364 calculation method Methods 0.000 claims description 12
- 238000012545 processing Methods 0.000 claims description 12
- 238000012625 in-situ measurement Methods 0.000 claims description 11
- 238000003384 imaging method Methods 0.000 claims description 8
- 230000002035 prolonged effect Effects 0.000 claims description 2
- 239000007787 solid Substances 0.000 abstract description 22
- 238000009826 distribution Methods 0.000 description 20
- 230000008569 process Effects 0.000 description 17
- 238000005516 engineering process Methods 0.000 description 13
- 239000002184 metal Substances 0.000 description 10
- 238000000691 measurement method Methods 0.000 description 7
- 230000004044 response Effects 0.000 description 7
- 230000003595 spectral effect Effects 0.000 description 7
- 238000009529 body temperature measurement Methods 0.000 description 6
- 239000008188 pellet Substances 0.000 description 6
- 230000008859 change Effects 0.000 description 5
- 238000000037 particle-tracking velocimetry Methods 0.000 description 5
- 230000005514 two-phase flow Effects 0.000 description 5
- 229910000831 Steel Inorganic materials 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 4
- 238000000149 argon plasma sintering Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 230000005855 radiation Effects 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 239000011324 bead Substances 0.000 description 3
- 239000003245 coal Substances 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 230000005484 gravity Effects 0.000 description 3
- 239000002923 metal particle Substances 0.000 description 3
- 238000000917 particle-image velocimetry Methods 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000007751 thermal spraying Methods 0.000 description 3
- 238000003325 tomography Methods 0.000 description 3
- 230000005457 Black-body radiation Effects 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000002360 explosive Substances 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000000779 smoke Substances 0.000 description 2
- 238000005481 NMR spectroscopy Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000012824 chemical production Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 238000007750 plasma spraying Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 239000004449 solid propellant Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000004861 thermometry Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radiation Pyrometers (AREA)
Abstract
The invention discloses a kind of high-temperature flight particle temperature, speed, partial size in-situ measuring method, step are as follows: Step 1: utilize camera shooting high-temperature flight particle image；When shooting, camera optical axis direction and plane where particle motion trajectory are vertical as far as possible；Step 2: handling according to image of the time for exposure to shooting, the motion profile of particle in image is obtained；Step 3: identification motion profile center and the direction of motion, utilize along the direction of motion image intensity transition calculate track length in pixels；Step 4: calculating each physical parameter: the temperature of particle trajectories, the speed of particle trajectories, particle trajectories diameter.The present invention can be used for observing temperature, the speed, size information of a large amount of particles within the scope of certain space, it can also be used to which measuring individual particle variation of temperature, speed, partial size even form in flight course can be widely used for the solid particle of various incandescents.
Description
Technical Field
The invention relates to an in-situ measurement technology for multiple physical fields of high-temperature flying particles, which can simultaneously measure the temperature, the speed and the particle size of the high-temperature flying particles and belongs to the technical field of analysis methods and measuring instruments.
Background
High-temperature flying particles widely exist in industrial and natural processes, such as a thermal spraying technology and a supersonic plasma spraying technology in a processing technology, preparation and reaction of particles in a chemical process, a combustion process of pulverized coal or solid fuel, flying fire particles causing solid fire to spread when a fire disaster occurs, and the like. Accurate measurement of parameters such as temperature, speed, particle size and particle size distribution of high-temperature flying particles is very important for the processes, especially simultaneous measurement of multiple parameters, comprehensive and accurate measurement data is favorable for fine control of a thermal spraying technology, optimization of a chemical production process, analysis of a pulverized coal ignition process, action research of flying particles in solid fire spreading and the like. Therefore, the measurement of the temperature, the speed, the particle size and the particle size distribution of the high-temperature flying particles is realized, and the method has great significance for revealing the essence and the rule of the thermal process and promoting the development of related processes.
However, the existing measurement techniques still have great limitations on the temperature, velocity, particle size and particle size distribution of high-temperature flying particles. As for the temperature, the measurement method of the high-temperature solid particles can be mainly classified into a contact type and a non-contact type. Contact measurement methods such as thermocouples require long-term contact with the high-temperature particles. Since the contact of the measuring device with the particles affects both the temperature distribution of the particles themselves and the movement trajectory of the particles, the contact measurement cannot accurately measure the temperature of the high-temperature flying particles. The non-contact measuring method has the advantages of wide measuring range, quick dynamic response, small influence on the measured object and the like. The traditional non-contact high-temperature measuring equipment mainly comprises a radiation pyrometer and a colorimetric pyrometer, and the temperature is calculated by utilizing the heat radiation characteristic of an object; the common characteristic of radiation pyrometers and colorimetric pyrometers is that only illumination information of a single spatial point can be collected, so that only single-point temperature can be measured, and high-temperature particles in motion are difficult to measure. The development of optical sensor technologies such as CCD and CMOS enables the sensors to be highly miniaturized and integrated into an image sensor array, and a digital camera formed by combining an image sensor and an optical lens can acquire illumination information in a wide range in space at a high density. The method is combined with an image processing technology, and the temperature information in a large range in the space can be measured by utilizing the Planck's law of black body radiation. However, this method has not been applied to the measurement of high temperature flying particles. For the measurement of the Particle flight speed, a non-contact measurement method based on Image processing is mainly used, and the method can be specifically classified into a Particle Image Velocimetry (PIV) and a Particle Tracking Velocimetry (PTV) based on a cross-correlation algorithm. The PIV technology can realize non-invasive measurement of a measurement area, obtain a two-dimensional flow field and visually display the structure of the flow field, but the technology has high requirements on measurement equipment, if double-pulse laser, a high-speed double-frame camera, a synchronous controller and the like are needed, a corresponding light path is complex, and meanwhile, the self-luminous intensity of high-temperature particles is high, so that the image is interfered, and the technology is difficult to be applied to the severe environment of high-temperature flying particles. In contrast, the PTV technique tracks the movement trajectory of particles using particle images. The method can be used for researching the instantaneous speeds of a plurality of particles and analyzing the spatial distribution of the particles, and can also be used for researching the speed change of a single particle in flight. However, the existing PTV technology cannot measure information such as temperature and particle size distribution of particles. For particle size and particle size distribution, two methods of measurement after sampling and in situ measurement are mainly used at present. For high-temperature flying particles, the physical properties of the particles in the flying process are difficult to maintain through measurement after sampling, and meanwhile, the thermal mechanical properties such as the temperature of the particles are also changed, so that the accuracy of particle size and particle size measurement of the high-temperature flying particles cannot be guaranteed through measurement after sampling. The in-situ measurement mainly comprises a light scattering method, a process tomography method, an image method and the like. The light scattering method solves the particle concentration distribution by using the intensity relation of the scattering of laser and tiny particles, and can solve the particle size distribution by using speckle images. The light scattering method has the advantages of strong penetrability and capability of measuring the gas-solid two-phase flow of a concentrated phase. However, the light scattering method is based on the Mie scattering theory, the solving process is complex, the equipment is complex, the cost is high, and only the particle size and the particle size distribution of a single space point can be measured. The process tomography method obtains the cross-sectional particle size distribution of the measured region by using methods such as electromagnetic waves, ultrasonic waves or nuclear magnetic resonance. However, the high-temperature flying particles are used as a high-temperature gas-solid two-phase flow medium, the flow form is complex and changeable, and the physical properties are unstable, so that the process tomography method is difficult to accurately measure the particle size and granularity of the high-temperature particles. The image method is to acquire image signals of high-temperature flying particles by using a CCD camera and then combine a digital image processing technology to obtain particle size and granularity parameters of the particles at the moment. Because the high-temperature flying particles can emit bright yellow incandescent light, the method does not need an external light source, can directly shoot the high-temperature particles, and has simpler device. However, this method has not been applied to the measurement of high temperature flying particles.
Chinese patent CN107202651A "a measurement device for combustion temperature field of microscale initiating explosive device and its temperature measurement method" proposes a non-contact measurement method for combustion temperature of high-temperature initiating explosive device, but cannot simultaneously measure information such as particle velocity and particle size. Chinese patent No. CN105548607A "probe and measurement method for measuring slip velocity of gas-solid two-phase flow particles" proposes a non-contact method for measuring velocity of normal temperature gas-solid two-phase flow particles, but this method cannot measure high temperature luminous solid particles and cannot measure temperature distribution of particles at the same time. Chinese patent publication No. CN106556556A, "an apparatus and method for measuring particle size and mass concentration of particles in smoke dust", proposes a non-contact method for measuring particle size and mass concentration of smoke dust particles, but this method uses a laser light source, is difficult to measure high-temperature luminescent solid particles, and cannot measure temperature and velocity of particles at the same time. In summary, no measurement method capable of simultaneously measuring multiple physical fields such as temperature, speed, particle size and particle size distribution of high-temperature flying particles exists at present, which greatly influences scientific research on high-temperature gas-solid two-phase flow and flying fire particle behavior in solid fire spread, and guidance and optimization of industrial processes such as thermal spraying technology, chemical granulation and pulverized coal firing.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide a method for measuring multiple physical fields such as temperature, velocity, particle size and particle size distribution of high temperature flying particles simultaneously, aiming at the defects of the prior art.
In order to solve the technical problems, the invention adopts the technical scheme that:
a measuring method capable of simultaneously measuring various physical parameters of high-temperature flying particles is characterized by comprising the following steps:
shooting an image of high-temperature flying particles by using a camera; when shooting, the direction of the optical axis of the camera is vertical to the plane of the particle motion track as much as possible;
step two, processing the shot image according to the exposure time to obtain the motion track of the particles in the image;
identifying the central position and the motion direction of the motion track, and calculating the pixel length of the track by using image intensity transition along the motion direction;
step four, calculating each physical parameter:
temperature of particle trajectory:
wherein,covering the average value of the R channel intensity of pixels for all particle track motion in the image;the average value of the G channel intensity of all the particle track motion coverage pixels in the image is obtained;covering the intensities of the R and G channels of a pixel for all particle trajectory movements in an image, respectivelyThe summed ratio; coefficient k1，k2And k3Polynomial fitting solving can be carried out by utilizing black body furnace calibration;
velocity of particle trajectory:
wherein V is the speed of movement of the particles; l is the length of the particle motion trajectory on the image; t is texpIs the exposure time of the camera; m is an image magnification;
diameter of particle track:
wherein D isobjIs the actual size of the object, DimgIs the width of the particle motion trajectory.
In the first step, the image shot by the camera is an image in a RAW format.
RAW is an "unprocessed" image format, which is the data obtained directly from the image sensor, with the most complete signal detail, which is not common, but which facilitates accurate measurements.
In contrast, common image formats such as JPG, BMP, PNG, and the like are image files obtained after RAW format image processing, and the processing process may affect data accuracy, even cause inaccurate measurement.
In the second step, the collected RAW image is decoded to perform demosaicing operation, and a linear interpolation algorithm is used to obtain a linear color image of the small ball track.
The in-situ measurement method provided by the invention can be used for simultaneously measuring the temperature, the speed and the particle size of the high-temperature flying particles. The invention uses a color CCD area-array camera to shoot high-temperature incandescent luminous flying solid particles, calculates the instantaneous temperature according to the ratio of the luminous intensity of different wave bands, solves the flying speed according to the flying distance of the flying solid particles in a certain time, and calculates the particle size according to the image of the flying track. The invention simultaneously quantitatively analyzes errors possibly occurring in temperature, speed and particle size measurement in principle. The invention can be used for observing the temperature, speed and particle size information of a large number of particles in a certain space range, and can also be used for measuring the temperature, speed, particle size and even form change of a single particle in the flight process. The invention does not need to use an emissivity model of the high-temperature solid particles and does not need to use external signals such as laser or electromagnetic waves and the like, and can be widely used for various incandescent luminous solid particles.
The invention does not need to use an emissivity model of high-temperature solid particles, does not need to use external signals such as laser or electromagnetic waves and the like, has simple measurement process and is easy to calibrate.
Compared with the prior art, the invention has at least the following beneficial effects: the invention can be used for observing the temperature, speed and particle size information of a large number of particles in a certain space range, and can also be used for measuring the temperature, speed, particle size and even form change of a single particle in the flight process. The invention can quantitatively calculate the measurement error ranges of temperature, speed and particle size in principle. The invention does not need to use an emissivity model of the high-temperature solid particles and does not need to use external signals such as laser or electromagnetic waves and the like, and can be widely used for various incandescent luminous solid particles. The invention has simple measuring process and easy calibration, and does not need to predict any parameter.
Drawings
FIG. 1 is a schematic diagram of a velocity projection, which results in errors in the velocity measurement;
FIG. 2 is a schematic view of perspective error caused by a change in image magnification when an object is far from a camera;
FIG. 3 is a schematic diagram of a ball drop test;
FIG. 4 shows the temperature calibration result of the color digital CCD camera;
FIG. 5 is an image (a) of the trajectory of a ball drop; temperature measurement (b); a speed measurement (c);
FIG. 6 is a distribution of pellet diameter measurements;
FIG. 7 is a schematic diagram (a) and an experimental setup diagram (b) of a metal cutting spark experiment;
FIG. 8 is a top view of the experimental apparatus, from which the size of the angle deviating from the optical axis direction of the camera when the metal particles fly can be calculated;
FIG. 9 is a plot of drag force versus error in velocity measurements as a function of particle size;
FIG. 10 is a graphical example of a metal cutting spark experiment (a) and a two-dimensional distribution of measurements of temperature and velocity at different flight distances;
fig. 11 is a distribution of particle diameter measurement results of metal cutting sparks.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The invention utilizes the spectral response characteristic of a color area array CCD camera, combines colorimetric temperature measurement with particle tracking speed measurement, and combines an image recognition and processing method to realize in-situ measurement of the temperature, the speed and the particle size of high-temperature flying particles. And calculating the temperature of each track in the particle track image by using a colorimetric thermometry method. And analyzing the particle track by using a particle tracking velocimetry method and calculating the velocity and the particle size distribution of each particle. The invention simultaneously quantitatively analyzes the uncertainty of temperature, speed and particle size measurement.
The method comprises the following steps: temperature calibration
The black body furnace is used as a standard radiation source for calibrating the color CCD camera, and the relationship between the temperature and the response intensity ratio of black body radiation in R and G channels of the color camera can be obtained:
whereinIs the average of the R-channel intensities of all particle trajectory motion covered pixels in the image,is the average value of the intensity of the G channel of all the particle track motion coverage pixels in the image, and the coefficient k1，k2And k3Polynomial fitting solution can be performed by using black body furnace calibration. For a particle motion track, the ratio of the R and G channel response intensityCan be expressed as:
where i and j represent pixel locations. WhereinAndrepresenting the R and G channel pixel intensities. The color CCD camera has three RGB color channels and can record three different waves of an objectThe spectral response intensity of the segment. For incandescent, luminescent solid particles, the R and G signals of a color camera are strong and therefore can be used for temperature measurement, with the following signal ratios:
where T is time, λ is wavelength, η (λ) is sensor spectral response efficiency, τ (λ) is the spectral transmittance of the imaging system, Δ λ is the spectral response bandwidth of the R and G channels E (λ, T) is the spectral radiant intensity of the solid particles, which can be determined by Planck's law as the solid particles emitting incandescent light can be considered to be black bodies:
where T is temperature, ε (λ) is spectral emissivity, c is speed of light, h is Planckian constant, and k is Boltzmann constant.
Noise from the camera image sensor can lead to uncertainty in the temperature calculation, which can be characterized by the following equation, since the temperature calculation for each particle involves multiple pixels in the image:
whereinIs the standard deviation of all R channel pixels,is the standard deviation of all G-channel pixels. Assuming that the pixels of the R and G channels are independent of each other, the total uncertainty of the temperature calculation is related to the R and G channels by:
the uncertainty of the temperature measurement can therefore be expressed as:
the 95% confidence interval for this particle temperature measurement is therefore T + -deltaT
Step two distance calibration
Calibrating by using calibration plate marked with scales, and measuring actual distance L between specific scales of calibration platereMeasuring the pixel distance L between corresponding scales in the imageimAnd solving the imaging size according to the pixel size p, and calculating the image magnification ratio M:
step three: shooting image
And shooting images of the high-temperature flying particles by using a camera. Care is taken to ensure that the direction of the optical axis of the camera is as perpendicular as possible to the plane of the motion trajectory of the particles. The camera uses a manual exposure mode, all automatic functions are turned off or set to none, and the image is saved as RAW data.
Step four: measurement of results
And processing the acquired image by using an upper computer. And decoding the collected RAW image to perform demosaicing operation, and obtaining a linear color image of the small ball track by using a linear interpolation algorithm without using any image enhancement calculation. The particles moving at high speed leave a motion track on the image within a certain exposure time, and the invention assumes that the particles move along a straight line within the exposure time. The center position and direction of the particle trajectory are identified, the pixel length of the trajectory is calculated using image intensity transitions along that direction, the image selection is determined and the image is cropped.
Respectively adding the intensities of the R and G channels of all the particle track coverage pixels in the image and calculating the ratioUsing a calibration formulaThe temperature of the particle trajectory is solved.
The velocity of the particles can be solved by:
where V is the velocity of the particle movement, L is the length of the particle movement trajectory on the image, texpIs the exposure time of the camera. Similarly, the diameter of a particle can be determined by the width of its motion trajectory:
Dobjis the actual size of the object, DimgIs the width of the particle motion trajectory.
Step five: error analysis
The present invention assumes that the particles move in a straight line during the exposure time, which assumption ignores the effect of air drag (drag) and gravity on the particles in flight. Error due to dragCan be characterized as:
wherein c isdIs the dimensionless drag coefficient, ρairAnd ρsparkAre the density of the air and the particles respectively,andthe velocity of the air and particles, respectively. Measurement error due to gravityCan be calculated from the following formula:
whereinIs the acceleration of gravity. It can be seen that the present invention may have larger speed measurement errors when the particles are smaller, the speed is higher, and the exposure time is longer.
The measurement of particle velocity and diameter is based on image processing, and there are two phenomena that can cause errors during imaging: projection and perspective. Projection refers to the mapping of a three-dimensional space to a two-dimensional image. When the particle motion direction and the camera line-of-sight direction are not perpendicular, the three-dimensional trajectory of the particle in space is projected on a two-dimensional image, which may cause a projection error, as shown in fig. 1.
Projection error ErrveloCan be characterized by the following formula:
wherein VrealIs the actual speed, VprojectedIs the projection speed. The relationship between the projection speed and the actual speed is
Vprojected＝Vreal·cos(θ) (15)
Where θ is the angle of the actual velocity with the plane of projection (CCD plane). The projection error is therefore:
Errvelo＝1-cos(θ) (16)
for the present invention, in order to reduce the projection error, the CCD camera needs to be placed at a position where the main optical axis of the camera is perpendicular to the plane of the particle motion trajectory, i.e. the CCD plane is parallel to the particle motion trajectory.
Perspective means that objects close to the camera are larger in the image, while objects far from the camera are smaller in the image, i.e. larger and smaller. When a particle is in flight close to or near the principle camera, errors in particle diameter measurement can result. The essence of the perspective error is that after the object distance changes, the magnification of the calibrated camera deviates, as shown in FIG. 2
The image of the area array CCD camera is a two-dimensional projection of a three-dimensional space, and the object-image relationship of the image follows a Gaussian imaging formula:
1/a+1/b＝1/f (17)
where is a object distance, b is an image distance, and f is a focal length. For an object with a certain object distance, the imaging size and the actual size can be represented by magnification:
when the particle moves a distance Δ a in the direction of the optical axis of the camera, the actual magnification M' is:
the size of the particles in the image at this time is:
D′img＝M′·Dobj(20)
the perspective error is therefore:
for the present invention, to reduce perspective errors, it is necessary to use a longer focal length lens while increasing the object-to-camera distance.
Example 1: drop of the ball
In order to achieve the aim, the effectiveness of the invention is verified, and an experimental system for simultaneously measuring the temperature, the speed and the particle size of high-temperature flying particles is provided. The method comprises the steps of heating the small balls to a specified temperature by using a tubular heating furnace, enabling the small balls to emit orange light, inclining the heating furnace to enable the small balls to naturally roll out and then freely fall, continuously shooting images of flying of the small balls by using a color CCD camera, and calculating the temperature, the speed change and the diameter of the small balls by using the images.
Environmental parameter
The diameter is 6.35mm, the height of the outlet of the heating furnace is 1.5m, the falling process is about 560us, the camera is fixed by a tripod, the direction of the optical axis of the camera is vertical to the plane of the movement track of the small ball, the distance between the camera and the plane is 3.3m, the focal length of the camera is 25.6mm, the field angle is 19.8 degrees multiplied by 28.9 degrees, the field size is 1.07 multiplied by 1.64m, the exposure time of the camera is 33.3ms, a manual exposure mode is used, all automatic functions are closed or set to be absent, and the image is stored as RAW original data. The pellet is directly contacted with a K-type bare wire thermocouple in a tube furnace, the thermocouple is connected to a temperature controller, the pellet is heated to 1000 ℃ and is released after being stabilized, and the pellet starts to move in a free falling body. The experimental environment is shown in fig. 3, where the images are recorded continuously using the high speed continuous shooting mode of the camera while the ball starts to roll.
The operation and calculation steps are as follows:
the method comprises the following steps: temperature calibration
2. The camera is arranged on the tripod and fixed at the position right facing the blackbody furnace, the height of the camera is the same as that of the outlet of the blackbody furnace, and the distance of the camera is the same as the object distance during measurement.
3. Setting the exposure time of the camera according to the requirements, adjusting the temperature of the black body furnace to 600 ℃, and collecting 5 images of the black body furnace after the temperature is stable
4. Setting the temperature of the black body furnace to 600-1500 ℃ at intervals of 50 ℃, and collecting each temperature point according to the method in the previous step
5. Storing the collected image in an upper computer, processing the image by using a calibration program to obtain a parameter curveThe calibration procedure was conducted as follows:
a) decoding the collected RAW image to perform demosaicing operation, and obtaining a linear color image of the black body furnace by using a linear interpolation algorithm without any image enhancement calculation
b) And inputting the set temperature of the black body furnace corresponding to each black body furnace image.
c) Cutting the image at the pixel position of the black body furnace in the input image
d) Respectively adding the intensities of the R and G channels of all the pixels of the cut images at the same temperature, and calculating the ratioObtaining the relation between the temperature and the color ratio by quadratic fitting
Step two: distance calibration
1. The camera is mounted on a tripod, and the optical axis of the camera is kept horizontal. The calibration plate marked with scales is placed perpendicular to the optical axis of the camera, the optical axis of the camera penetrates through the center of the calibration plate, and the distance from the calibration plate to the camera is the same as the object distance during measurement.
2. The exposure time of the camera is prolonged, the imaging of the calibration plate is clear, and all automatic functions are closed or set to be absent by using a manual exposure mode.
3. A calibration plate image is taken. The actual distance between specific scales of the calibration plate is measured.
4. And measuring the pixel distance between corresponding scales in the image, solving the imaging size of the image according to the pixel size, and calculating the image magnification M.
Step three: shooting image
1. The camera is arranged on a tripod and fixed at a position facing the tubular furnace, so that the optical axis of the camera is ensured to be vertical to the plane of the falling track of the small balls. The height of the optical axis of the camera is 0.8m, and the distance is 3.3 m.
2. The camera exposure time was set to 33.3ms, the manual exposure mode was used, all automatic functions were turned off or set to none, and the image was saved as RAW data.
3. The pellets were heated to 1000 ℃ and stabilized using a tube furnace, and the tube furnace was tilted using a furnace tilt table. The pellets begin to roll and leave the tube furnace by gravity and begin free fall movement. The images are continuously recorded with the high speed continuous shooting mode of the camera while the ball starts to roll. The image recording was stopped after the bead landed. And acquiring a track image of the small ball flying in the air.
Step four: measurement of results
1. And storing the acquired images in an upper computer, decoding the acquired RAW images to perform demosaicing operation, and obtaining a linear color image of the small ball track by using a linear interpolation algorithm without using any image enhancement calculation. And inputting a test group number corresponding to each image and an image sequence.
2. And identifying the central position and the direction of the particle track by using Hough transform, calculating the pixel length of the track by using image intensity transition along the direction, determining an image selection area and cutting the image.
3. Respectively adding the intensities of the R and G channels of all the particle track coverage pixels in the image and calculating the ratioUsing a calibration formulaThe temperature of the particle trajectory is solved.
4. Calculating the movement displacement of the particles in the exposure time by using the recognized track length of the particles and combining the calibrated magnification, and solving the running speed of the particles
5. And (3) taking the vertical direction of the identified particle track direction by utilizing the identified particle track direction, calculating the pixel width of the particle track by utilizing image intensity transition, and solving the particle size of the particles by combining the calibrated magnification.
Calibrated temperature to color ratio relationshipAs shown in fig. 4. The captured trace image of the ball is shown in fig. 5 (a). The measured temperature results are shown in fig. 5(b), in which the blue dotted line is the set temperature. The measured velocity results are shown in fig. 5(c), in which the blue dotted line is the gravitational acceleration. The measured bead diameter is shown in fig. 6, where the blue dotted line is the actual bead diameter.
Example 2: metal cutting spark
Basic idea
To further illustrate the present invention, a measurement example of a metal cutting spark is provided. The embodiment comprises a metal cutting machine, a steel bar, a color digital camera, a tripod and the like. When the reinforcing bar is cut using a metal cutter, the cut metal fine particles are scattered outward and emit light. When the metal particles fly, a color CCD camera is used for shooting images of flying of a plurality of particles, and the temperature, the speed distribution and the particle diameter distribution of the metal particles are measured and calculated by utilizing the method.
Environmental parameter
The model of the metal cutting machine is Makita 9207SPC, the model of the cutting piece is DeWALT DW3511, the diameter is 180mm, and the model of the cut Steel bar workpiece is Hillman-Weld-Steel-Rebar-11802. The camera is fixed by a tripod, the direction of the optical axis of the camera is vertical to the rotation plane of the cutting blade, the camera is 1.71m away from the plane, the focal length of the camera is 54.6mm, the field angle is 14.3 degrees multiplied by 9.59 degrees, and the field size is 430 multiplied by 287 mm. The exposure time is 1.0ms, a manual exposure mode is used, all automatic functions are turned off or set to none, and the image is saved as RAW data. The experimental environment is shown in fig. 7.
The operation and calculation steps are as follows:
the method comprises the following steps: temperature calibration: same as example 1 except for the exposure time setting
Step two: distance calibration: same as example 1 except for the camera working distance
Step three: shooting image
1. The camera is arranged on the tripod and fixed at a position which is opposite to the contact position of the cutting machine and the workpiece, and the optical axis of the camera is ensured to be vertical to the plane of the cutting blade.
2. And cutting the steel bar by using a cutting machine, wherein the metal sparks continuously splash and fly out along the rotating direction of the cutting blade.
3. The exposure time of the camera is set to 1.0ms, a plurality of images are continuously shot, and the instantaneous flight trajectory of a large number of particles is recorded. Step four: measurement of results
1. And storing the acquired image into an upper computer, decoding the acquired RAW image to perform demosaicing operation, and obtaining a linear color image of the particle track by using a linear interpolation algorithm without using any image enhancement calculation. And inputting a test group number corresponding to each image and an image sequence.
2. The region of each particle track in the image is identified and cropped. The center position and direction of the particle trajectory are identified using hough transform, and the pixel length of the trajectory is calculated using image intensity transitions along that direction.
3. Respectively adding the intensities of the R and G channels of all the particle track coverage pixels in the image and calculating the ratioUsing a calibration formulaThe temperature of the particle trajectory is solved.
4. Calculating the movement displacement of the particles in the exposure time by using the recognized track length of the particles and combining the calibrated magnification, and solving the running speed of the particles
5. And (3) taking the vertical direction of the identified particle track direction by utilizing the identified particle track direction, calculating the pixel width of the particle track by utilizing image intensity transition, and solving the particle size of the particles by combining the calibrated magnification.
Step five: error analysis
1. Projection error
a) The electric saw, the steel bar and the spark splash condition are shot from the upper part, and a top view is obtained. As shown in fig. 8.
b) The maximum deviation angle of the spark spray is measured from a top view. For the experimental conditions of example 2, the maximum deviation angle is θ ═ tan-1(75/475) 8.97 °. I.e. the deviation angle of the particles from the plane of the cutting blade in flight is less than +/-8.97 deg.
c) The maximum error of the velocity measurement caused by the projection is calculated by using the angle as Errvelo1-cos (θ) 1.23%. The measurement error caused by the projection is therefore less than ± 1.23% in example 2.
2. Perspective error
a) The maximum deviation distance Δ a of the spark spatter was measured as 75mm using a top view.
b) The maximum error in particle size measurement due to perspective is calculated as Err using this distanceD4.33%. Therefore, the particle size measurement error caused by the perspective effect is less than ± 4.33% in example 2.
3. Drag error
Drag error is related to particle diameter, speed of motion, etc. By using the measured particle velocity, temperature and peak value of the particle size, the velocity measurement error caused by the particle drag force can be calculated. The calculation results are shown in fig. 9.
The captured image of the spark of the electric saw is shown in fig. 10 (a). The measurement results of the temperature and velocity of the high-temperature flying particles at different distances are shown in fig. 10 (b). The measured high temperature flight particle diameter is shown in fig. 11.
Claims (5)
1. An in-situ measurement method for temperature, speed and particle size of high-temperature flying particles is characterized by comprising the following steps:
shooting an image of high-temperature flying particles by using a camera; when shooting, the direction of the optical axis of the camera is vertical to the plane of the particle motion track as much as possible;
step two, processing the shot image according to the exposure time to obtain the motion track of the particles in the image;
identifying the central position and the motion direction of the motion track, and calculating the pixel length of the track by using image intensity transition along the motion direction;
step four, calculating each physical parameter:
temperature of particle trajectory:
wherein,covering the average value of the R channel intensity of pixels for all particle track motion in the image;the average value of the G channel intensity of all the particle track motion coverage pixels in the image is obtained;the ratio of the intensities of R and G channels of all particle track motion coverage pixels in the image after addition is respectively obtained; coefficient k1，k2And k3Carrying out polynomial fitting solution by utilizing black body furnace calibration;
velocity of particle trajectory:
wherein V is the speed of movement of the particles; l is the length of the particle motion trajectory on the image; t is texpIs the exposure time of the camera; m is an image magnification;
diameter of particle track:
wherein D isobjIs the actual size of the object, DimgIs the width of the particle motion trajectory.
2. The in-situ measurement method according to claim 1, wherein in the first step, the image captured by the camera is a RAW format image.
3. The in-situ measurement method according to claim 2, wherein in the second step, the collected RAW image is decoded and demosaiced, and a linear interpolation algorithm is used to obtain a linear color image of the trajectory of the ball.
4. An in-situ measurement method as claimed in any one of claims 1 to 3, wherein the coefficient k is obtained by calibration using a blackbody furnace1，k2And k3The method comprises the following steps:
the camera is arranged on a tripod and fixed at a position right facing the blackbody furnace, the height of the camera is the same as that of the outlet of the blackbody furnace, and the distance is the same as the object distance during measurement;
setting the exposure time of a camera as required, adjusting the temperature of the black body furnace to 600 ℃, and collecting 5 images for the black body furnace after the temperature is stable;
setting the temperature of the black body furnace to be 600-1500 ℃, setting the interval to be 50 ℃, and collecting each temperature point according to the method in the previous step;
storing the collected image in an upper computer, processing the image by using a calibration program to obtain a parameter curve
The calibration procedure was conducted as follows:
a) decoding the collected RAW image to perform demosaicing operation, and obtaining a linear color image of the black body furnace by using a linear interpolation algorithm without any image enhancement calculation;
b) inputting the set temperature of the black body furnace corresponding to each black body furnace image;
c) inputting the pixel position of the black body furnace in the image, and cutting the image;
d) adding the intensities of R and G channels of all the pixels of the cut image at the same temperaturePost-calculation of the ratioObtaining the relation between the temperature and the color ratio by quadratic fitting
5. The in-situ measurement method according to claim 4, wherein the image magnification M is calculated by:
the camera is arranged on a tripod, and the optical axis of the camera is kept horizontal; placing a calibration plate marked with scales perpendicular to an optical axis of a camera, wherein the optical axis of the camera penetrates through the center of the calibration plate, and the distance from the calibration plate to the camera is the same as the object distance during measurement;
the exposure time of the camera is prolonged, so that the calibration plate can be imaged clearly, and all automatic functions are closed or set to be absent by using a manual exposure mode;
shooting images of the calibration plate, and measuring the actual distance between specific scales of the calibration plate;
and measuring the pixel distance between corresponding scales in the image, solving the imaging size of the image according to the pixel size, and calculating the image magnification M.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910240464.2A CN109990834A (en) | 2019-03-27 | 2019-03-27 | High-temperature flight particle temperature, speed, partial size in-situ measuring method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910240464.2A CN109990834A (en) | 2019-03-27 | 2019-03-27 | High-temperature flight particle temperature, speed, partial size in-situ measuring method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109990834A true CN109990834A (en) | 2019-07-09 |
Family
ID=67131775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910240464.2A Pending CN109990834A (en) | 2019-03-27 | 2019-03-27 | High-temperature flight particle temperature, speed, partial size in-situ measuring method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109990834A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111242979A (en) * | 2020-01-16 | 2020-06-05 | 上海交通大学 | Three-dimensional space spattering identification and tracking method in laser welding process |
| CN112034198A (en) * | 2020-07-03 | 2020-12-04 | 朱建国 | High-shooting-speed bullet continuous-firing initial speed measuring method |
| CN113310857A (en) * | 2021-05-27 | 2021-08-27 | 上海交通大学 | Turbulent combustion field four-dimensional carbon smoke particle primary particle size distribution measuring system and method thereof |
| CN114500882A (en) * | 2022-01-24 | 2022-05-13 | 中国科学院烟台海岸带研究所 | Method for measuring behavioral parameters of sports animals |
| CN115100234A (en) * | 2022-06-20 | 2022-09-23 | 宁波大学 | Method and device for measuring impact force of solid particles on vertical shaft structure |
| CN116311783A (en) * | 2023-05-16 | 2023-06-23 | 中国船舶集团有限公司第七一九研究所 | Ship cabin monitoring alarm system based on artificial intelligence |
Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2108655B (en) * | 1981-08-31 | 1985-07-03 | Ottica Ist Naz | A method and apparatus for measuring the distribution of pulverized particles |
| US4990795A (en) * | 1988-07-30 | 1991-02-05 | Horiba, Ltd. | Particle counter with photointensity compensation |
| CN101173956A (en) * | 2007-06-27 | 2008-05-07 | 清华大学 | Device and method for measuring solid particle speed of gas/solid phase stream in pneumatic conveying pipe |
| CN101509931A (en) * | 2009-03-16 | 2009-08-19 | 浙江大学 | Method and apparatus for on-line measuring two-dimension speed and particle size distribution of granules in pipe |
| JP2010101881A (en) * | 2008-09-27 | 2010-05-06 | Flowtech Research Inc | Particle photographing apparatus |
| CN102410974A (en) * | 2011-12-14 | 2012-04-11 | 华北电力大学 | On-line measurement method for particle size distribution and shape distribution of granules in airflow conveying pipe |
| CN102520014A (en) * | 2011-12-14 | 2012-06-27 | 华北电力大学 | On-line prediction method of pollutant emissions based on flame free radicals and temperature measurement |
| CN102706459A (en) * | 2012-06-21 | 2012-10-03 | 华东理工大学 | Detection device and method for three-dimensional temperature field in combustion chamber of single-CCD imaging system |
| CN104180908A (en) * | 2014-08-07 | 2014-12-03 | 华能国际电力股份有限公司 | RAW image radiation temperature measuring device and method |
| CN105548607A (en) * | 2015-12-23 | 2016-05-04 | 东南大学 | Probe of measuring gas-solid two-phase flow particle slip velocity and measurement method |
| CN105738648A (en) * | 2016-04-19 | 2016-07-06 | 中国科学院过程工程研究所 | Method for on-line measuring particle speed in polyphase system |
| CN106556556A (en) * | 2016-11-28 | 2017-04-05 | 华中科技大学 | The particle diameter and the device and method of mass concentration of granule in a kind of measurement flue dust |
| CN106644102A (en) * | 2017-01-17 | 2017-05-10 | 浙江大学 | Method for measuring temperature of hydrocarbon flame based on colored CCD camera |
| CN107202651A (en) * | 2017-07-05 | 2017-09-26 | 西安交通大学 | A kind of minute yardstick priming system combustion temp field measuring device and its temp measuring method |
| CN107525590A (en) * | 2017-08-16 | 2017-12-29 | 清华大学 | A kind of apparatus and method for monitoring in-flight high-temperature particle temperature field |
| CN109297874A (en) * | 2018-11-30 | 2019-02-01 | 浙江大学 | It is a kind of for measuring the holographic method for real-time measurement and device of moving particle partial size |
-
2019
- 2019-03-27 CN CN201910240464.2A patent/CN109990834A/en active Pending
Patent Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2108655B (en) * | 1981-08-31 | 1985-07-03 | Ottica Ist Naz | A method and apparatus for measuring the distribution of pulverized particles |
| US4990795A (en) * | 1988-07-30 | 1991-02-05 | Horiba, Ltd. | Particle counter with photointensity compensation |
| CN101173956A (en) * | 2007-06-27 | 2008-05-07 | 清华大学 | Device and method for measuring solid particle speed of gas/solid phase stream in pneumatic conveying pipe |
| JP2010101881A (en) * | 2008-09-27 | 2010-05-06 | Flowtech Research Inc | Particle photographing apparatus |
| CN101509931A (en) * | 2009-03-16 | 2009-08-19 | 浙江大学 | Method and apparatus for on-line measuring two-dimension speed and particle size distribution of granules in pipe |
| CN102410974A (en) * | 2011-12-14 | 2012-04-11 | 华北电力大学 | On-line measurement method for particle size distribution and shape distribution of granules in airflow conveying pipe |
| CN102520014A (en) * | 2011-12-14 | 2012-06-27 | 华北电力大学 | On-line prediction method of pollutant emissions based on flame free radicals and temperature measurement |
| CN102706459A (en) * | 2012-06-21 | 2012-10-03 | 华东理工大学 | Detection device and method for three-dimensional temperature field in combustion chamber of single-CCD imaging system |
| CN104180908A (en) * | 2014-08-07 | 2014-12-03 | 华能国际电力股份有限公司 | RAW image radiation temperature measuring device and method |
| CN105548607A (en) * | 2015-12-23 | 2016-05-04 | 东南大学 | Probe of measuring gas-solid two-phase flow particle slip velocity and measurement method |
| CN105738648A (en) * | 2016-04-19 | 2016-07-06 | 中国科学院过程工程研究所 | Method for on-line measuring particle speed in polyphase system |
| CN106556556A (en) * | 2016-11-28 | 2017-04-05 | 华中科技大学 | The particle diameter and the device and method of mass concentration of granule in a kind of measurement flue dust |
| CN106644102A (en) * | 2017-01-17 | 2017-05-10 | 浙江大学 | Method for measuring temperature of hydrocarbon flame based on colored CCD camera |
| CN107202651A (en) * | 2017-07-05 | 2017-09-26 | 西安交通大学 | A kind of minute yardstick priming system combustion temp field measuring device and its temp measuring method |
| CN107525590A (en) * | 2017-08-16 | 2017-12-29 | 清华大学 | A kind of apparatus and method for monitoring in-flight high-temperature particle temperature field |
| CN109297874A (en) * | 2018-11-30 | 2019-02-01 | 浙江大学 | It is a kind of for measuring the holographic method for real-time measurement and device of moving particle partial size |
Non-Patent Citations (3)
| Title |
|---|
| 张琮昌等: "煤粉颗粒速度和粒径在线测量的轨迹成像法", 《中国电机工程学报》 * |
| 杨永军主编: "《特殊条件下的温度测量》", 31 January 2009 * |
| 黎石竹等: "RGB三波段消光法测量细微颗粒粒度分布研究", 《光学学报》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111242979A (en) * | 2020-01-16 | 2020-06-05 | 上海交通大学 | Three-dimensional space spattering identification and tracking method in laser welding process |
| CN111242979B (en) * | 2020-01-16 | 2023-05-12 | 上海交通大学 | Method for recognizing and tracking splashing of three-dimensional space in laser welding process |
| CN112034198A (en) * | 2020-07-03 | 2020-12-04 | 朱建国 | High-shooting-speed bullet continuous-firing initial speed measuring method |
| CN113310857A (en) * | 2021-05-27 | 2021-08-27 | 上海交通大学 | Turbulent combustion field four-dimensional carbon smoke particle primary particle size distribution measuring system and method thereof |
| CN114500882A (en) * | 2022-01-24 | 2022-05-13 | 中国科学院烟台海岸带研究所 | Method for measuring behavioral parameters of sports animals |
| CN114500882B (en) * | 2022-01-24 | 2023-12-15 | 中国科学院烟台海岸带研究所 | Method for measuring behavioral parameters of sports animal |
| CN115100234A (en) * | 2022-06-20 | 2022-09-23 | 宁波大学 | Method and device for measuring impact force of solid particles on vertical shaft structure |
| CN115100234B (en) * | 2022-06-20 | 2023-04-07 | 宁波大学 | Method and device for measuring impact force of solid particles on vertical shaft structure |
| CN116311783A (en) * | 2023-05-16 | 2023-06-23 | 中国船舶集团有限公司第七一九研究所 | Ship cabin monitoring alarm system based on artificial intelligence |
| CN116311783B (en) * | 2023-05-16 | 2024-01-02 | 中国船舶集团有限公司第七一九研究所 | Ship cabin monitoring alarm system based on artificial intelligence |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109990834A (en) | High-temperature flight particle temperature, speed, partial size in-situ measuring method | |
| CN105606222B (en) | A kind of measuring device and measuring method of flame three-dimensional temperature field | |
| US10254193B2 (en) | Systems and methods for optical scanning of fluid transport pipelines | |
| CN103076265B (en) | A kind of distribution of particles and the measurement apparatus of diameter | |
| CN108072459A (en) | A kind of method for measuring steel billet temperature field and calculating its radiation intensity | |
| CN107167249A (en) | One camera two waveband molten bath color comparison temperature measurement method and system | |
| US20100265987A2 (en) | Method and Apparatus for Measuring the Temperature of a Sheet Material | |
| CN109506810A (en) | A kind of the polychrome temperature measuring equipment and method of flame two-dimensional temperature field | |
| US10852195B2 (en) | Method of measuring temperature of an object to be measured, dust temperature and dust concentration | |
| CN101664794B (en) | Continuous casting two cold closed chamber casting blank surface temperature field measuring device | |
| CN110514305A (en) | The optimization method of flame temperature field measuring system light-field camera quantity and seat in the plane arrangement | |
| CN101886951A (en) | System and method for analyzing movable target aiming performance of high repetition frequency laser | |
| JP6239660B2 (en) | Calibration apparatus and calibration method | |
| CN108132197B (en) | Uncertainty analysis and calculation method for impact temperature of transparent material | |
| Mates et al. | Calibration of a two-color imaging pyrometer and its use for particle measurements in controlled air plasma spray experiments | |
| Wang et al. | Experimental and Numerical Investigations of Effusion Cooling for High Pressure Turbine Components: Part 1—Experimental Study With PSP | |
| SI24410A (en) | System and method for contactless temperature measuring with a cameraworking in the visible part of the light spectrum | |
| Kelly et al. | A novel multi-band plenoptic pyrometer used for temperature measurements of strand burner plumes | |
| RU2556310C2 (en) | Device for remote measurement of geometric parameters of profiled objects | |
| CN106248147A (en) | A kind of plasma spray coating Fe coatings on-line measurement device | |
| JPH08184499A (en) | Radiation pyrometer | |
| Żaba et al. | Application of non-destructive methods to quality assessment of pattern assembly and ceramic mould in the investment casting elements of aircraft engines | |
| US8536514B2 (en) | Method and apparatus for measuring the temperature of a sheet material | |
| Wang et al. | Radiation spectral analysis and particle temperature/velocity measurement in plasma spray with one-color camera | |
| ES2713268T3 (en) | Procedure for the simultaneous measurement of the thickness and temperature of an oxide layer |
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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190709 |
|
| RJ01 | Rejection of invention patent application after publication |