CN107271105A - It is a kind of to measure the three-line pendulum of eccentric object rotation inertia - Google Patents
It is a kind of to measure the three-line pendulum of eccentric object rotation inertia Download PDFInfo
- Publication number
- CN107271105A CN107271105A CN201710624660.0A CN201710624660A CN107271105A CN 107271105 A CN107271105 A CN 107271105A CN 201710624660 A CN201710624660 A CN 201710624660A CN 107271105 A CN107271105 A CN 107271105A
- Authority
- CN
- China
- Prior art keywords
- cylinder
- lower wall
- optoelectronic switch
- line pendulum
- cavity
- 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
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M1/00—Testing static or dynamic balance of machines or structures
- G01M1/10—Determining the moment of inertia
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
- G09B23/00—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes
- G09B23/06—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics
- G09B23/08—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics for statics or dynamics
- G09B23/10—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics for statics or dynamics of solid bodies
Landscapes
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Mathematical Physics (AREA)
- Pure & Applied Mathematics (AREA)
- Business, Economics & Management (AREA)
- Algebra (AREA)
- Educational Administration (AREA)
- Educational Technology (AREA)
- Theoretical Computer Science (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The three-line pendulum of eccentric object rotation inertia can be measured the invention discloses a kind of, belongs to Experiments of Machanics instrument technical field, including support, upper disk, lower wall and three suspension wires, the lower wall is a cylinder；The outer cover of the lower wall is provided with the cylinder of a both ends open；The cylinder interior is provided with cavity, and the inner surface of the cylinder is provided with multiple ventholes, and the cylinder is provided with air admission hole, and the air admission hole connects compressor；The compressor is by the air admission hole to the gas pressurized in the cavity, and the gas in the cavity is entered in the gap between the cylinder and the lower wall by the venthole, is then discharged from the upper open end and lower open end of the cylinder.The present invention is simple in construction, can both measure the non-rotary inertia around barycenter rotating object, and the rotary inertia around barycenter rotating object can be measured again, and measurement efficiency is high, accuracy of measurement is good.
Description
Technical field
The invention belongs to Experiments of Machanics instrument technical field, more particularly to a kind of it can measure eccentric object rotation inertia
Three-line pendulum.
Background technology
Three-line pendulum is to be used in Experiment of College Physics measure the laboratory apparatus commonly used in object rotation inertia experiment, existing
Three-line pendulum includes support, upper disk, lower wall and three suspension wires between upper disk and lower wall, and wherein lower wall is used for placing to be measured
Object, the rotary inertia of object under test is measured using the change of three-line pendulum rotation period and quality before and after object under test is placed.
But, existing three-line pendulum has the following disadvantages：
First, situation when existing three-line pendulum can only measure object around barycenter rotation, because object does not revolve around barycenter
When turning, three-line pendulum can produce horizontal swing, the condition of the measurement rotary inertia of three-line pendulum thus be destroyed, so existing
Some three-line pendulums can not measure the non-rotary inertia around barycenter rotating eccentricity object, also be unfavorable for student for rotary inertia
Understand.
2nd, the rotary inertia of barycenter rotating object is surrounded even for measurement, also due to a variety of causes, also easily occurs
Transverse shakiness, therefore the necessary extreme care when testing, but be difficult to completely avoid transverse shakiness, it both have impact on measurement
Efficiency, also have impact on the degree of accuracy of measurement.
3rd, three-line pendulum is when work, it is desirable to which the angle of rotation is below 5 degree, and existing three-line pendulum does not have angle of rotation
The display device of degree, its rotational angle size is estimated to grasp with experimenter, is unfavorable for controlling measurement error.
4th, existing three-line pendulum, the rotation of lower wall is, by upper dish driving, to use inconvenience.While upper disk and branch
It can be relatively rotated between frame, so the angle between lower wall each several part and support is unfixed, such structure is unfavorable for turning
The installation of dynamic cycle and rotational angle measurement apparatus and use.
The content of the invention
The technical problems to be solved by the invention are：Offer is a kind of can to measure the three-line pendulum of eccentric object rotation inertia,
It is simple in construction, the non-rotary inertia around barycenter rotating eccentricity object can have both been measured, can have been measured again around barycenter gig
The rotary inertia of body, and measurement efficiency is high, accuracy of measurement is good.
In order to solve the above technical problems, the technical scheme is that：It is a kind of to measure eccentric object rotation inertia
Three-line pendulum, including support, upper disk, lower wall and three suspension wires between the upper disk and the lower wall, the lower wall is
One cylinder；
The outer cover of the lower wall is provided with the cylinder of a both ends open, and the cylinder is fixedly installed on the support；
The internal diameter of the cylinder, which is slightly larger than inside the external diameter of the lower wall, the circular cylindrical shell, is provided with cavity, the cylinder
Venthole of the inner surface provided with multiple connections cavitys, and the air admission hole of the cavity, institute are communicated with the cylinder
Air admission hole connection compressor is stated, the cylinder and the lower wall are coaxially disposed；
The compressor is by the air admission hole to the gas pressurized in the cavity, and the gas in the cavity passes through institute
State venthole to enter in the gap between the cylinder and the lower wall, then from the upper open end and under shed of the cylinder
End discharge.
As an improvement, the height of the cylinder is less than the height of the lower wall, and during lower wall rotation above and below it
End is exposed at outside the cylinder all the time.
As an improvement, the upper disk is fixedly installed on the support；The three-line pendulum also includes rotational angle report
Alert device, the rotational angle alarm includes optoelectronic switch and warning circuit, and the optoelectronic switch is installed in the side of the support
Face, the upper end of the side wall of the lower wall is provided with bands absorption and the reflective tape positioned at the bands absorption both sides, the bands absorption pair
The central angle answered is 5 °；
During initial rest state, the light emitting portion of the optoelectronic switch launches light irradiation in the central position of the bands absorption
Put, when the rotational angle of the lower wall is more than 5 °, the light receiving part of the optoelectronic switch is received from reflective tape reflection
Light, so as to start warning circuit work.
As a further improvement, the three-line pendulum also includes period measurement optoelectronic switch and the cycle being connected electrically meter
When device, the period measurement optoelectronic switch is fixed on the bracket；During initial rest state, the period measurement optoelectronic switch
Light emitting portion transmitting light irradiation reflective tape described in the bands absorption and one intersection；When the lower wall is rotated,
The cycle timer measures rotation period.
Employ after above-mentioned technical proposal, the beneficial effects of the invention are as follows：
Because three-line pendulum devises tubular lower wall, cylinder and compressor, the compressor passes through the air admission hole
To the gas pressurized in the cavity, the gas in the cavity enters the cylinder and the lower wall by the venthole
Between gap in, then discharged from the upper open end and lower open end of the cylinder, thus lower wall and cylinder can form class
Like the structure of air bearing, when measuring the rotary inertia of object, lower wall is supported by gas, it is possible to prevente effectively under
Disk is swung laterally, and so can both have been measured the non-rotary inertia around barycenter rotating eccentricity object, and can have been measured and surround again
The rotary inertia of barycenter rotating object, substantially increases measurement efficiency, and accuracy of measurement is good.
The present invention provide it is a kind of can measure the three-line pendulum of eccentric object rotation inertia, it is simple in construction, can both measure
The non-rotary inertia around barycenter rotating eccentricity object, can measure the rotary inertia around barycenter rotating object, and measurement again
Efficiency high, accuracy of measurement are good.
Because the height of the cylinder is less than the height of the lower wall, and its upper and lower side is exposed at all the time during lower wall rotation
Outside the cylinder, support of the gas to lower wall is further increased.
Because the three-line pendulum also includes rotational angle alarm, it can so prevent that rotational angle occur excessive in measurement
The problem of, further increase the precision of measurement；Due to the presence of similar air bearing, it is possible to directly operate lower wall with hand
Rotate, improve the convenience used, because the upper disk is fixedly installed on the support, thus between upper disk and support not
It can relatively rotate, the variation of the relative position of bands absorption and optoelectronic switch can be prevented, reach the mesh of accurate control rotational angle
's.
Because the three-line pendulum also includes period measurement optoelectronic switch and the cycle timer that is connected electrically, thus can be with
Convenient record rotation period.
Brief description of the drawings
Fig. 1 is the structural representation of the embodiment of the present invention；
In figure：1- supports, the upper disks of 2-, 3- lower walls, 31- bands absorptions, 32- reflective tapes, 4- suspension wires, 5- cylinders, 51- cavitys,
52- ventholes, 53- air admission holes, 6- rotational angle alarms, 61- optoelectronic switches, 62- warning circuits.
Embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, it is right below in conjunction with drawings and Examples
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.
As shown in figure 1, a kind of can measure the three-line pendulum of eccentric object rotation inertia, including support 1, upper disk 2, lower wall 3
And three suspension wires 4 between upper disk 2 and lower wall 3, lower wall 3 is a cylinder.
The outer cover of lower wall 3 is provided with the cylinder 5 of a both ends open, and cylinder 5 is fixedly installed on support 1.
The internal diameter of cylinder 5 is slightly larger than the external diameter of lower wall 3, and the enclosure interior of cylinder 5 is provided with cavity 51, and the inner surface of cylinder 5 is set
There is the venthole 52 of multiple connection cavitys 51, and the air admission hole 53 of cavity 51 is communicated with cylinder 5, the connection of air admission hole 53 is calmed the anger
Machine (not shown), cylinder 5 and lower wall 3 are coaxially disposed.
Compressor is by air admission hole 53 to the gas pressurized in cavity 51, and the gas in cavity 51 is entered by venthole 52
Into the gap between cylinder 5 and lower wall 3, then discharged from the upper open end and lower open end of cylinder 5.
So, lower wall 3 can form the structure of similar air bearing with cylinder 5, when measuring the rotary inertia of object, lead to
Cross gas to be supported lower wall 3, it is possible to prevente effectively from lower wall 3 is swung laterally, so can both measure non-around barycenter
The rotary inertia of rotating eccentricity object, can measure the rotary inertia around barycenter rotating object again, substantially increase measurement effect
Rate, and accuracy of measurement is good.
In order to further improve support of the gas to lower wall 3, the height of cylinder 5 is less than the height of lower wall 3, and 3 turns of lower wall
Its upper and lower side is exposed at outside cylinder 5 all the time when dynamic.
In order to prevent from occurring in measurement, rotational angle is excessive, further improves the precision of measurement, it is preferred that upper disk 2 is fixed
It is installed on support 1；Three-line pendulum also includes rotational angle alarm 6, and rotational angle alarm 6 includes optoelectronic switch 61 and alarm
Circuit 62, optoelectronic switch 61 is installed in the side of support 1, and the side wall of lower wall 3 is provided with bands absorption 31 and positioned at bands absorption 31
The reflective tape 32 of both sides, the corresponding central angle of bands absorption 31 is 5 °.
During initial rest state, the light emitting portion of optoelectronic switch 61 launches light irradiation in the middle position of bands absorption 31,
In measurement, when the rotational angle of lower wall 3 is more than 5 °, the light receiving part of optoelectronic switch 61 receives what is reflected from reflective tape 32
Light, works so as to start warning circuit 62.
It is relatively unrotatable between above-mentioned upper disk 2 and support 1, due to the presence of similar air bearing, it is possible to directly
Rotated with hand operation lower wall 3, improve the convenience used, and the relative position of bands absorption 31 and optoelectronic switch 61 can be prevented
The variation put, reaches the purpose of accurate control rotational angle.
Rotation period is recorded for convenience, and three-line pendulum also includes period measurement optoelectronic switch (not shown) and electric with it
The cycle timer (not shown) of connection, period measurement optoelectronic switch is installed on support 1；During initial rest state, week
Intersection of the light irradiation of the light emitting portion transmitting of phase measurement optoelectronic switch in reflective tape 32 described in bands absorption 31 and one；Instantly
When disk 3 is rotated, cycle timer record rotation period.
Specifically, after the rotation of lower wall 3, if the light irradiation of the light emitting portion transmitting of period measurement optoelectronic switch is reflective
Intersection with 32 and bands absorption 31, period measurement optoelectronic switch can produce pulse signal, and period measurement timing device utilizes these
Pulse measure rotation period.
It should be noted that above-mentioned warning circuit 62 is techniques known, for example can using indicator lamp or
The mode of buzzer alarm etc., and its concrete structure is well known to those skilled in the art, and will not be repeated here.
The present invention provide it is a kind of can measure the three-line pendulum of eccentric object rotation inertia, it is simple in construction, can both measure
The non-rotary inertia around barycenter rotating eccentricity object, can measure the rotary inertia around barycenter rotating object, and measurement again
Efficiency high, accuracy of measurement are good.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all essences in the present invention
Any modifications, equivalent substitutions and improvements made within refreshing and principle etc., should be included in the scope of the protection.
Claims (4)
1. the three-line pendulum of eccentric object rotation inertia can be measured a kind of, including support, upper disk, lower wall and located at the upper disk
Three suspension wires between the lower wall, it is characterised in that the lower wall is a cylinder；
The outer cover of the lower wall is provided with the cylinder of a both ends open, and the cylinder is fixedly installed on the support；
The internal diameter of the cylinder, which is slightly larger than inside the external diameter of the lower wall, the circular cylindrical shell, is provided with cavity, the cylinder it is interior
Venthole of the surface provided with multiple connections cavitys, and be communicated with the air admission hole of the cavity on the cylinder, it is described enter
Stomata connects compressor, and the cylinder and the lower wall are coaxially disposed；
The compressor by the air admission hole to the gas pressurized in the cavity, gas in the cavity by it is described go out
Stomata is entered in the gap between the cylinder and the lower wall, is then arranged from the upper open end and lower open end of the cylinder
Go out.
2. according to claim 1 can measure the three-line pendulum of eccentric object rotation inertia, it is characterised in that the cylinder
Height be less than the lower wall height, and the lower wall rotation when its upper and lower side be exposed at all the time outside the cylinder.
3. according to claim 1 or 2 can measure the three-line pendulum of eccentric object rotation inertia, it is characterised in that described
Upper disk is fixedly installed on the support；The three-line pendulum also includes rotational angle alarm, the rotational angle alarm bag
Optoelectronic switch and warning circuit are included, the optoelectronic switch is installed in the side of the support, and the upper end of the side wall of the lower wall is set
There are bands absorption and a reflective tape positioned at the bands absorption both sides, the corresponding central angle of the bands absorption is 5 °；
During initial rest state, the light emitting portion of the optoelectronic switch launches light irradiation in the middle position of the bands absorption,
When the rotational angle of the lower wall is more than 5 °, the light receiving part of the optoelectronic switch receives what is reflected from the reflective tape
Light, so as to start the warning circuit work.
4. according to claim 3 can measure the three-line pendulum of eccentric object rotation inertia, it is characterised in that three line
Pendulum also includes period measurement optoelectronic switch and the cycle timer being connected electrically, and the period measurement optoelectronic switch is installed in institute
State on support；During initial rest state, the light irradiation of the light emitting portion transmitting of the period measurement optoelectronic switch is inhaled described
The intersection of reflective tape described in light belt and one, when the lower wall is rotated, the cycle timer measures rotation period.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710624660.0A CN107271105A (en) | 2017-07-27 | 2017-07-27 | It is a kind of to measure the three-line pendulum of eccentric object rotation inertia |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710624660.0A CN107271105A (en) | 2017-07-27 | 2017-07-27 | It is a kind of to measure the three-line pendulum of eccentric object rotation inertia |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107271105A true CN107271105A (en) | 2017-10-20 |
Family
ID=60078279
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710624660.0A Pending CN107271105A (en) | 2017-07-27 | 2017-07-27 | It is a kind of to measure the three-line pendulum of eccentric object rotation inertia |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107271105A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111811733A (en) * | 2020-07-01 | 2020-10-23 | 上海航天精密机械研究所 | Universal device for measuring axial rotational inertia of eccentric revolving body |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0629362A (en) * | 1992-07-07 | 1994-02-04 | Sony Corp | Evaluating apparatus for impact resistance of semiconductor wafer |
| CN1450339A (en) * | 2002-04-11 | 2003-10-22 | 中国科学院自动化研究所 | Driving wheel capable of being dectected for steering angle |
| CN200972729Y (en) * | 2006-04-24 | 2007-11-07 | 辽宁师范大学 | Photoelectric control system of angular momentum conservation measurement instrument |
| CN101281619A (en) * | 2008-05-26 | 2008-10-08 | 吴明星 | Encoding method for encoded word wheel of counter |
| CN101701968A (en) * | 2009-11-10 | 2010-05-05 | 三一重工股份有限公司 | Detecting device and method for detecting at least one rotation parameter of rotating object |
| CN101825483A (en) * | 2010-05-07 | 2010-09-08 | 浙江工业大学 | Motion accompanying suspension device providing constant hanging force |
| CN202083520U (en) * | 2011-01-04 | 2011-12-21 | 包贤强 | Electromagnetic braking type trilinear pendulum |
| CN102410337A (en) * | 2011-10-25 | 2012-04-11 | 清华大学 | Permanent magnet low-frequency multidegree of freedom vibration isolation mechanism based on negative stiffness principle |
| CN202947835U (en) * | 2012-12-18 | 2013-05-22 | 山西省电力公司大同供电分公司 | Instrument for measuring swing angle and period of three-wire pendulum |
| CN103162904A (en) * | 2013-03-19 | 2013-06-19 | 江南大学 | Three-line pendulum |
| CN103808461A (en) * | 2012-11-14 | 2014-05-21 | 陈均钧 | Device for measuring rotational inertia of rigid body through magnetic suspension rotating platform |
| CN106448362A (en) * | 2016-10-18 | 2017-02-22 | 江南大学 | Three-line pendulum facilitating control of pendulum angle |
| CN106979841A (en) * | 2017-04-28 | 2017-07-25 | 沈阳建筑大学 | High-precision rotation inerttia instrument |
-
2017
- 2017-07-27 CN CN201710624660.0A patent/CN107271105A/en active Pending
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0629362A (en) * | 1992-07-07 | 1994-02-04 | Sony Corp | Evaluating apparatus for impact resistance of semiconductor wafer |
| CN1450339A (en) * | 2002-04-11 | 2003-10-22 | 中国科学院自动化研究所 | Driving wheel capable of being dectected for steering angle |
| CN200972729Y (en) * | 2006-04-24 | 2007-11-07 | 辽宁师范大学 | Photoelectric control system of angular momentum conservation measurement instrument |
| CN101281619A (en) * | 2008-05-26 | 2008-10-08 | 吴明星 | Encoding method for encoded word wheel of counter |
| CN101701968A (en) * | 2009-11-10 | 2010-05-05 | 三一重工股份有限公司 | Detecting device and method for detecting at least one rotation parameter of rotating object |
| CN101825483A (en) * | 2010-05-07 | 2010-09-08 | 浙江工业大学 | Motion accompanying suspension device providing constant hanging force |
| CN202083520U (en) * | 2011-01-04 | 2011-12-21 | 包贤强 | Electromagnetic braking type trilinear pendulum |
| CN102410337A (en) * | 2011-10-25 | 2012-04-11 | 清华大学 | Permanent magnet low-frequency multidegree of freedom vibration isolation mechanism based on negative stiffness principle |
| CN103808461A (en) * | 2012-11-14 | 2014-05-21 | 陈均钧 | Device for measuring rotational inertia of rigid body through magnetic suspension rotating platform |
| CN202947835U (en) * | 2012-12-18 | 2013-05-22 | 山西省电力公司大同供电分公司 | Instrument for measuring swing angle and period of three-wire pendulum |
| CN103162904A (en) * | 2013-03-19 | 2013-06-19 | 江南大学 | Three-line pendulum |
| CN106448362A (en) * | 2016-10-18 | 2017-02-22 | 江南大学 | Three-line pendulum facilitating control of pendulum angle |
| CN106979841A (en) * | 2017-04-28 | 2017-07-25 | 沈阳建筑大学 | High-precision rotation inerttia instrument |
Non-Patent Citations (4)
| Title |
|---|
| 张天霄: "提高ZME-1实验台转动惯量测试精度方法的探讨", 《试验技术与试验机》 * |
| 徐登峰: "三线摆水平隔振器原理与应用", 《北京航天航空大学学报》 * |
| 李刚常: "用三线摆测定物体对非质心轴的转动惯量", 《力学与实践》 * |
| 石大力: "三线摆测定不规则物体定轴转动惯量的实验研究", 《装备制造技术》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111811733A (en) * | 2020-07-01 | 2020-10-23 | 上海航天精密机械研究所 | Universal device for measuring axial rotational inertia of eccentric revolving body |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN208921701U (en) | A kind of liftable acquisition water quality monitoring equipment | |
| ES2556776T3 (en) | Dosing device with damage monitoring | |
| CN107271105A (en) | It is a kind of to measure the three-line pendulum of eccentric object rotation inertia | |
| US4160385A (en) | Pipe quality monitoring mechanism | |
| KR102163207B1 (en) | Thermocouple temperature detector mounting structure for high viscosity mixing material mixer | |
| CN206787665U (en) | A kind of device for measuring level of ground water | |
| US3248941A (en) | Soap film type gas flow measuring device | |
| CN107246934A (en) | It is a kind of to measure the non-three-line pendulum around barycenter rotating object rotary inertia | |
| CN108362353A (en) | A kind of switching regulator wall material-level detecting device | |
| CN107957503A (en) | A kind of multi-functional speed measuring device | |
| CN107389265A (en) | A kind of three-line pendulum | |
| CN107576360A (en) | Small-bore ultrasonic water meter | |
| CN207866402U (en) | A kind of torque sensor for automobile | |
| US4408494A (en) | Ultrasound measuring instrument | |
| CN104458502A (en) | Device and method for measuring blood viscosity by laser reflection | |
| CN211158353U (en) | Water flow indicator for fire fighting system | |
| CN208383769U (en) | A kind of heat-resisting quantity detection device of automotive hub | |
| CN210089842U (en) | Equipment operation vibration field monitoring device | |
| CN207516391U (en) | A kind of multi-functional speed measuring device | |
| CN207248282U (en) | Water-level instrumentation | |
| US3835372A (en) | Switch closure device for meters | |
| ES2259421T3 (en) | DEVICE AND PROCEDURE FOR THE DETERMINATION OF THE ABSENCE OF VOLTAGE IN POLYPHASIC POWER LINES. | |
| CN215115040U (en) | Helium mass spectrometer leak detector spray gun with jet flow monitoring function | |
| CN203274881U (en) | Powder weighting device | |
| CN1050664C (en) | Rotary target type flowmeter |
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: 20171020 |
|
| RJ01 | Rejection of invention patent application after publication |