CN209878544U - Surface tension coefficient measuring device - Google Patents
Surface tension coefficient measuring device Download PDFInfo
- Publication number
- CN209878544U CN209878544U CN201920415938.8U CN201920415938U CN209878544U CN 209878544 U CN209878544 U CN 209878544U CN 201920415938 U CN201920415938 U CN 201920415938U CN 209878544 U CN209878544 U CN 209878544U
- Authority
- CN
- China
- Prior art keywords
- surface tension
- semi
- measuring device
- tension coefficient
- linear array
- 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.)
- Expired - Fee Related
Links
Abstract
The utility model discloses a surface tension coefficient measuring device, which comprises a light source, a slit diaphragm, a semi-transparent semi-reflecting mirror, a linear array CCD and a flat plate; parallel light rays vertically irradiate the curved liquid surface near the flat plate through the semi-transparent semi-reflective mirror after the edges of the light beams are adjusted through the slit diaphragm; the linear array CCD collects the reflected light signal conversion data of the curved liquid surface and transmits the data to the computer; the utility model discloses a crooked liquid level of diaphragm control light beam border position realization laser beam scanning obtains the change of reflection light field edge relative position that arouses by the detection distance difference and confirms the liquid level slope, through measuring incident beam boundary light position relative change and the liquid level slope that corresponds with it, combines the utility model provides an analytic relation obtains the surface tension coefficient; measuring device adopts complete relative measurement, has eliminated the influence of contact angle in theory, still has real-time, harmless, non-contact's characteristics when effectively avoiding systematic error.
Description
Technical Field
The utility model relates to a physical quantity measurement technical field, in particular to surface tension coefficient measuring device.
Background
The measurement of the surface tension coefficient of the liquid has important significance for researching the properties of an object, and the traditional measurement method generally has the characteristics of complex operation, low speed, low precision and the like; at present, a board inserting method and a laser reflection method derived from the board inserting method are adopted, so that the operation is simpler, and the precision is higher; however, the maximum height of liquid rising needs to be measured in the plate inserting method, the absolute position of boundary light needs to be determined in the laser reflection method, and the flat plate needs to be strictly vertical to the horizontal plane; the rising height of the liquid and the absolute position of the boundary light cannot be effectively determined and measured, so that the final measured surface tension is influenced to a certain extent, and the measurement cannot be carried out under the condition that the flat plate has a certain inclination angle.
SUMMERY OF THE UTILITY MODEL
To exist not enough among the prior art, the utility model provides a surface tension coefficient measuring device to adopt complete relative measurement, eliminate the influence of contact angle in theory, effectively avoid systematic error.
In order to achieve the above purpose, the technical scheme of the utility model is that:
a surface tension coefficient measuring device comprises a light source, a slit diaphragm, a semi-transparent semi-reflecting mirror, a linear array CCD, a computer and a flat plate; the light source is used for generating light beams which are parallel rays; the slit diaphragm is arranged on the path of the parallel light rays, and the parallel light rays form vertically downward parallel light rays after being reflected by the semi-transparent semi-reflector through the slit diaphragm; the flat plate is arranged in the liquid to be detected, vertically downward parallel light rays vertically irradiate the liquid to be detected and are positioned on two sides of the flat plate; the linear array CCD is movably arranged above the liquid to be measured, and the vertical downward parallel light rays are reflected by the liquid to be measured and then irradiate on the linear array CCD after passing through the semi-transparent semi-reflective mirror; the linear array CCD collects the optical signals, converts the optical signals into data signals and transmits the data signals to the computer.
Further, the light source adopts a laser.
Furthermore, the device also comprises a beam expander and a convex lens, wherein the beam expander and the convex lens are sequentially arranged between the light source and the slit diaphragm and are positioned on the path of the light.
Furthermore, the slit diaphragm adopts a slit diaphragm with adjustable width.
Further, still include the support, the support includes cradling piece, base, X axle adjust knob, Y axle adjust knob and Z axle adjust knob, and the cradling piece slidable sets up on the base, and linear array CCD installs on the cradling piece, and X axle adjust knob is used for adjusting the displacement of cradling piece X axle direction, and Y axle adjust knob is used for adjusting the displacement of cradling piece Y axle direction, and Z axle adjust knob is used for adjusting the displacement of cradling piece Z axle direction.
Furthermore, the semi-transparent semi-reflecting mirror is obliquely arranged above the liquid level to be measured, and the included angle between the semi-transparent semi-reflecting mirror and the horizontal plane is 45 degrees.
Compared with the prior art, the beneficial effects of the utility model are that:
the utility model relates to a surface tension coefficient measuring device, through laser beam scanning flat board insert the liquid to form crooked liquid level to one side, obtain the change of reflection light field edge relative position that causes by the difference of detection distance and confirm the liquid level slope, need not measure the absolute coordinate of incident light, reflection light field edge, detection position, only need measure incident light beam boundary light position relative change and the liquid level slope that corresponds with it, and then obtain the surface tension coefficient; measuring device adopts complete relative measurement, has eliminated the influence of contact angle in theory, still has real-time, harmless, non-contact's characteristics when effectively avoiding systematic error technically.
Drawings
Fig. 1 is a schematic view of the overall structure of the measuring device of the present invention;
fig. 2 is an optical schematic diagram of the measurement method according to the present invention.
The device comprises a light source 1, a beam expander 2, a convex lens 3, a slit diaphragm 4, a semi-transparent semi-reflecting mirror 5, a linear array CCD6, a computer 7, a flat plate 8, a support 9, a support rod 91, a base 92, an X-axis adjusting knob 93, a Y-axis adjusting knob 94 and a Z-axis adjusting knob 95.
Detailed Description
The present invention will be further explained with reference to the drawings and the detailed description.
Referring to fig. 1, the surface tension coefficient measuring device of the present invention includes a light source 1, a beam expander 2, a convex lens 3, a slit diaphragm 4, a half-transmitting and half-reflecting mirror 5, a linear array CCD6, a computer 7, a flat plate 8 and a support 9;
the light source 1 adopts a laser, and the light source 1 is used for generating light beams which are parallel rays; a beam expander 2 and a convex lens 3 are arranged on a path of a Gaussian beam emitted by a light source 1 to form a collimated and parallel beam, and the collimated and parallel beam irradiates a slit diaphragm 4; a slit diaphragm 4 is arranged on the parallel light path, and the position of the boundary incident light of the parallel light on the curved liquid surface is controlled by the slit diaphragm 4; after the parallel light rays pass through the slit diaphragm 4 and are reflected by the semi-transparent semi-reflective mirror 5, vertical downward parallel light rays are formed, the semi-transparent semi-reflective mirror 5 is obliquely arranged, and an included angle between the semi-transparent semi-reflective mirror 5 and the horizontal direction is 45 degrees; vertically downward parallel light rays vertically downward irradiate on the curved liquid level of the liquid to be measured; the flat plate 8 is arranged in the liquid to be measured, and the liquid to be measured is vertically irradiated by the vertically downward parallel light.
The flat plate 8 is arranged in the liquid to be detected, the flat plate 8 is inserted into the liquid to be detected at a preset inclination angle, and the liquid to be detected forms bending surfaces on two sides of the flat plate 8 due to a wetting effect; the vertical downward parallel light rays irradiate on the curved liquid surfaces on the two sides of the flat plate 8 and are reflected by the liquid surfaces, the vertical downward parallel light rays are irradiated on a linear array CCD6 arranged above the liquid to be detected through a half-mirror 5 after being reflected, the linear array CCD6 collects optical signals and converts the optical signals into data signals, the linear array CCD6 transmits the data signals to the computer 7, and the surface tension coefficient of the liquid to be detected is obtained through data processing and operation of the computer 7.
The linear array CCD6 is arranged on the support 9, the support 9 comprises a support rod 91, a base 92, an X-axis adjusting knob 93, a Y-axis adjusting knob 94 and a Z-axis adjusting knob 95, and the support rod 91 is slidably arranged on the base 92; the linear array CCD6 is installed on cradling piece 91, and X axle adjust knob 93 is used for adjusting the displacement of cradling piece 91X axle direction, and Y axle adjust knob 94 is used for adjusting the displacement of cradling piece 91Y axle direction, and Z axle adjust knob 95 is used for adjusting the displacement of cradling piece 91Z axle direction.
The calculation principle is as follows:
referring to fig. 2, the flat plate 8 is obliquely inserted into the liquid to be measured, and the liquid surfaces on both sides of the flat plate 8 form a curved liquid surface due to the wetting effect of the liquid; establishing a Cartesian coordinate system: the vertical direction is taken as the Z axis, the direction along the solid-liquid contact line is taken as the Y axis, and the extension direction of the curved surface of the curved liquid surface is taken as the X axis.
Taking the right side of the plate 8 as an example: vertically downward parallel light beams vertically enter the curved liquid surface, and a light ray 1 is defined as a boundary incident light ray, and a light ray 1' is a reflected light ray of the light ray 1; any ray inside the ray 2-bit boundary incident ray is known to be positioned on the right side of the ray 1 'according to the geometric relation, namely the reflected ray 2' of the ray 2; in the distribution of a bright field area observed by an observation screen above the liquid to be measured, the edge of the bright field is formed by light 1'; moving the observation screen by delta h along the vertical direction, and correspondingly changing the bright field edge by a horizontal displacement delta L; assuming that an included angle beta between the liquid level of the liquid to be measured and the horizontal direction at the boundary incident ray is combined with a trigonometric function relation tan2 beta as 2z '/(1-z'2) And obtaining a mathematical expression of the slope z' of the curved liquid level at the position of the boundary incident ray as follows:
wherein z' is the slope of the curved liquid surface at the position of the boundary incident ray,
deltah is the vertical displacement of the viewing screen moving in the vertical direction,
Δ L is the horizontal displacement of the bright-field edge corresponding to the change.
According to the slope of each point on the curved liquid surface, the surface tension coefficient gamma and the contact angle theta are obtained by solving Young-LaplacecAnd the constraint relation of the included angle between the flat plate 8 and the horizontal direction to the slope z' of the bending liquid surface is as follows:
wherein z' is the slope of the curved liquid surface at the position of the boundary incident ray, gamma is the surface tension coefficient, theta is the included angle between the flat plate 8 and the horizontal direction, and theta iscIs the contact angle of the liquid to be measured;
c is constant, and the contact angle theta of the constant C and the liquid to be measuredcAnd the angle theta between the flat plate 8 and the horizontal direction; when the material of the flat plate 8, the included angle between the flat plate 8 and the horizontal direction and the type of liquid are determined, namely C is a constant;
rho is the density of the liquid, and g is the acceleration of gravity; alpha is the capillary constant of the liquid to be measured,
f (z ') is a variable related to the slope z',
x is the abscissa of the curved liquid level at the position of the boundary incident ray;
(2) the formula reflects the surface tension coefficient gamma and the contact angle thetacThe constraint relation of the included angle between the flat plate 8 and the horizontal direction to the slope z' of the bending liquid surface; the mathematical expression for the surface tension coefficient γ obtained from equation (2) is:
wherein x isiIs the abscissa of the boundary incident ray at the point i of the meniscus,
xjthe abscissa of the boundary incident ray at the point j of the meniscus,
z′iis the slope of point i above the meniscus,
z′jis the slope of point j above the meniscus;
Δxijthe position variation of the boundary incident ray between the i point and the j point of the curved liquid level;
f(z′i) Is equal to the slope z'iA variable of interest;
f(z′j) Is equal to the slope z'jThe variables involved.
A method for measuring surface tension coefficient comprises the following steps:
step 1, starting a light source 1, and obtaining collimated and parallel light rays through a beam expander 2 and a convex lens 3; adjusting a slit diaphragm 4 to limit the boundary of parallel rays, and reflecting the parallel rays through a half-transmitting and half-reflecting mirror 5 to form vertically downward parallel rays; the vertical downward parallel light rays are reflected by the curved liquid surface and then irradiate on the linear array CCD 6; recording the abscissa x of the incident ray on the meniscus at the vertically downward parallel ray boundaryi；
Step 2, acquiring optical signals by using the linear array CCD6 to obtain the edge position of a bright field and the position of a linear array CCD 6; then moving the linear array CCD6 along the vertical direction, and recording the edge position of a bright field and the position of the linear array CCD 6; obtaining the vertical displacement variation delta h of the position of the recording linear array CCD6iAnd bright field edge displacement change amount DeltaLi(ii) a Calculating to obtain the slope z 'of the point i on the meniscus'iAnd slope z'iThe variable f (z'i) Slope z 'of point i on the meniscus'iAnd slope z'iThe variable f (z'i) The mathematical expressions of (a) are respectively;
wherein,. DELTA.hiThe vertical displacement variation of the linear array CCD position when the incident light of the parallel light boundary is at the point i on the curved liquid surface,
ΔLithe displacement variation of the edge position of the bright field when the incident light of the parallel light boundary is at the point i on the curved liquid surface;
z′iis the slope of point i above the meniscus;
step 3, adjusting the slit diaphragm 4 to limit the boundary of the parallel light rays, and recording the abscissa x of the incident light rays of the vertically downward parallel light ray boundary on the curved liquid surfacejObtaining the position variation delta x of the boundary incident ray between the i point and the j point of the curved liquid levelijThe mathematical expression is;
Δxij＝xi-xj；
step 4, repeating the step 2 to obtain the slope z 'of the j point on the meniscus'jAnd slope z'jThe variable f (z'j) Slope z 'of j point on meniscus'jAnd slope z'jThe variable f (z'j) The mathematical expressions of (a) are respectively:
wherein,. DELTA.hjThe vertical displacement variation of the linear array CCD position when the incident light of the parallel light boundary is at the point j on the curved liquid surface,
ΔLjthe displacement variation of the edge position of the bright field when the incident light of the parallel light boundary is at the point j on the curved liquid surface;
z′jis the slope of point j above the meniscus;
step 5, solving the surface tension coefficient gamma, wherein the mathematical expression of the surface tension coefficient gamma is as follows:
and 6, repeating the steps 2-5, and taking the arithmetic mean of the obtained multiple groups of surface tension coefficient values to obtain the final surface tension coefficient.
Claims (6)
1. A surface tension coefficient measuring device is characterized by comprising a light source (1), a slit diaphragm (4), a semi-transparent semi-reflecting mirror (5), a linear array CCD (6), a computer (7) and a flat plate (8); the light source (1) is used for generating light beams which are parallel rays; the slit diaphragm (4) is arranged on the path of the parallel light rays, and the parallel light rays are reflected by the semi-transparent and semi-reflective mirror (5) through the slit diaphragm (4) to form vertical and downward parallel light rays; the flat plate (8) is arranged in the liquid to be detected, vertically downward parallel light rays vertically irradiate the liquid to be detected and are positioned on two sides of the flat plate (8); the linear array CCD (6) is movably arranged above the liquid to be measured, and the vertical downward parallel light rays are reflected by the liquid to be measured, then pass through the semi-transparent semi-reflective mirror (5) and then irradiate on the linear array CCD (6); the linear array CCD (6) collects the optical signals and converts the optical signals into data signals, and the data signals are transmitted to the computer (7).
2. A surface tension coefficient measuring device as claimed in claim 1, characterized in that the light source (1) is a laser.
3. A surface tension coefficient measuring device according to claim 1, further comprising a beam expander (2) and a convex lens (3), the beam expander (2) and the convex lens (3) being arranged in sequence between the light source (1) and the slit diaphragm (4) and being located in the path of the light.
4. A surface tension coefficient measuring device as claimed in claim 1, characterized in that the slit diaphragm (4) is a slit diaphragm with adjustable width.
5. The surface tension coefficient measuring device according to claim 1, further comprising a support (9), wherein the support (9) comprises a support rod (91), a base (92), an X-axis adjusting knob (93), a Y-axis adjusting knob (94) and a Z-axis adjusting knob (95), the support rod (91) is slidably arranged on the base (92), the linear array CCD (6) is mounted on the support rod (91), the X-axis adjusting knob (93) is used for adjusting the displacement of the support rod (91) in the X-axis direction, the Y-axis adjusting knob (94) is used for adjusting the displacement of the support rod (91) in the Y-axis direction, and the Z-axis adjusting knob (95) is used for adjusting the displacement of the support rod (91) in the Z-axis direction.
6. A surface tension coefficient measuring device according to claim 1, characterized in that the half mirror (5) is arranged obliquely above the liquid level to be measured, and the angle between the half mirror (5) and the horizontal plane is 45 °.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920415938.8U CN209878544U (en) | 2019-03-28 | 2019-03-28 | Surface tension coefficient measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920415938.8U CN209878544U (en) | 2019-03-28 | 2019-03-28 | Surface tension coefficient measuring device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209878544U true CN209878544U (en) | 2019-12-31 |
Family
ID=68957400
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920415938.8U Expired - Fee Related CN209878544U (en) | 2019-03-28 | 2019-03-28 | Surface tension coefficient measuring device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209878544U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109813636A (en) * | 2019-03-28 | 2019-05-28 | 陕西科技大学 | A kind of surface tension coefficient measuring device and its measurement method |
| CN112284984A (en) * | 2020-10-19 | 2021-01-29 | 陕西科技大学 | Solid surface energy measuring device and method based on light reflection |
-
2019
- 2019-03-28 CN CN201920415938.8U patent/CN209878544U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109813636A (en) * | 2019-03-28 | 2019-05-28 | 陕西科技大学 | A kind of surface tension coefficient measuring device and its measurement method |
| CN109813636B (en) * | 2019-03-28 | 2024-03-22 | 陕西科技大学 | Surface tension coefficient measuring device and measuring method thereof |
| CN112284984A (en) * | 2020-10-19 | 2021-01-29 | 陕西科技大学 | Solid surface energy measuring device and method based on light reflection |
| CN112284984B (en) * | 2020-10-19 | 2024-03-08 | 陕西科技大学 | Solid surface energy measuring device and method based on light reflection |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102066872B (en) | Method for calibrating thickness gauge | |
| CN109341546B (en) | Light beam calibration method of point laser displacement sensor at any installation pose | |
| CN101699222B (en) | Star sensor calibrator and method for calibrating high-precision star sensor | |
| CN107121093A (en) | A kind of gear measurement device and measuring method based on active vision | |
| KR101484528B1 (en) | Tilt sensor for a device and method for determining the tilt of a device | |
| CN209878544U (en) | Surface tension coefficient measuring device | |
| CN105157606A (en) | Non-contact type high-precision three-dimensional measurement method and measurement device for complex optical surface shapes | |
| CN103091992A (en) | Workpiece position correction device and correction method | |
| CN109269393A (en) | A kind of surface whole audience microscopic three-dimensional pattern automatic tester | |
| CN109141273B (en) | DMD-based high-speed moving target deformation measurement system and method | |
| CN107796718A (en) | Brineling system and method | |
| CN109884061A (en) | Utilize the method for common focus point migration microscopic system measuring medium surface roughness | |
| CN101726279B (en) | Linearly measurement method and device | |
| CN101504273A (en) | Measuring apparatus and method for object plane micro-nano dimension | |
| CN109813636B (en) | Surface tension coefficient measuring device and measuring method thereof | |
| CN105091778B (en) | Obform guide rail one side characteristic detection method and device based on line-structured laser | |
| CN113804696A (en) | Method for determining size and area of defect on surface of bar | |
| CN102445854A (en) | Workpiece stage vertical position measuring system | |
| CN110966937B (en) | Large member three-dimensional configuration splicing method based on laser vision sensing | |
| CN106840030A (en) | A kind of two-dimentional long-range profile detection means and detection method | |
| CN208636260U (en) | One kind being used for the microscopical positioning system of ultrasonic scanning | |
| JP2010256107A (en) | Measuring device and measurement method | |
| CN112129672A (en) | Liquid contact angle measuring instrument by interference method | |
| CN207301331U (en) | A kind of trigonometry laser range sensor | |
| CN101968342A (en) | Orthogonal fine scanning based method for measuring mass centers of tiny light spots |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20191231 Termination date: 20210328 |