CN204480559U - Natural frequency measures demonstration device - Google Patents
Natural frequency measures demonstration device Download PDFInfo
- Publication number
- CN204480559U CN204480559U CN201520140547.1U CN201520140547U CN204480559U CN 204480559 U CN204480559 U CN 204480559U CN 201520140547 U CN201520140547 U CN 201520140547U CN 204480559 U CN204480559 U CN 204480559U
- Authority
- CN
- China
- Prior art keywords
- water
- glass container
- natural frequency
- loudspeaker
- signal generator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The utility model relates to a kind of natural frequency and measures demonstration device, belongs to teaching aid.The utility model base plate is installed with glass container, described glass container is cylindrical shape, cylinder glass appearance wall is respectively equipped with rule and water yield datum line, described glass container bottom is provided with water inlet, water inlet is connected with aqua storage tank water delivering orifice by water injecting pipeline, and aqua storage tank is connected with water pump by pipeline; Described water injection pipe is provided with diffluence pass, diffluence pass is connected to dispensing pipe; Be provided with loudspeaker above glass container, loudspeaker is connected with audio signal generator, and the glass container near loudspeaker is provided with decibelmeter, and described audio signal generator is connected with power supply.The utility model water filling have employed the method injected from glass container bottom, avoids the water surface reforming phenomena produced from top water filling, is changed effective measurement volumes of container, thus natural frequency is changed by water filling.The utility model achieves the natural frequency carrying out measuring demonstration object in teaching; The minimum excitation density of resonance, and the relation between the size of volume and natural frequency.
Description
Technical field
The present invention relates to a kind of natural frequency and measure demonstration device, belong to teaching aid.
Background technology
Any object all has natural frequency, is decided by its factor such as material, structure, size, proterties, and natural frequency is the intrinsic a kind of physical features of object self.When object be subject to a certain characteristic frequency instigate time, can cause and vibrate and make amplitude reach maximal value, this frequency is exactly the natural frequency of object., how does witness object have natural frequency? so far, in teaching, commercial instruments is not still had for demonstration, thus feel to query and puzzlement, therefore, be necessary to invent a kind of inherent frequency demonstrator, fill up teaching blank, so that student can from perceptually obtaining cognition.
Natural frequency is with a wide range of applications in production practices, such as near the buildings of railway, when there being train to pass through, will be vibrated and be passed to buildings by ground, if vibration frequency is just identical with the natural frequency of buildings, this buildings will produce resonance, and amplitude also can be increasing to making building damage.All public address equipment can be used in grand theater, auditorium, if the natural frequency of some equipment of buildings or its indoor, just identical with a certain frequency of the sound equipment that amplifies, also can produce resonance, the sound wave of this resonance reaches microphone again, will form positive feedback and cause ear-piercing uttering long and high-pitched sounds.Natural frequency characteristic is industrially widely used, especially at electronic technology field, such as: the components and parts such as transistor, telefault, high frequency capacitance, obvious from household electrical appliance impression.
Summary of the invention
The object of the present invention is to provide a kind of substantial teaching equipment, deepen student's perceptual knowledge, fill up the blank natural frequency of teaching and measure demonstration device.
Technical solution:
The present invention includes: base plate, audio signal generator, decibelmeter, loudspeaker, described base plate is installed with glass container, described glass container is cylindrical shape, cylinder glass appearance wall is respectively equipped with rule and water yield datum line, described glass container bottom is provided with water inlet, water inlet is connected with aqua storage tank water delivering orifice by water injecting pipeline, and aqua storage tank is connected with water pump by pipeline; Described water injection pipe is provided with diffluence pass, diffluence pass is connected to dispensing pipe; Be provided with loudspeaker above glass container, loudspeaker is connected with audio signal generator, and the glass container near loudspeaker is provided with decibelmeter, and described audio signal generator is connected with power supply.
Water inlet on described glass container and the water delivering orifice on aqua storage tank are separately installed with stop valve, dispensing pipe are installed fine setting water valve.
Described decibelmeter is hung on glass container top.
Described loudspeaker is placed on support, described support comprises: the column of setting triangular in shape, and the supporting plate being fixedly mounted on column top, described supporting plate has the through hole placing loudspeaker, described through hole is corresponding with described glass container opening, and through hole is provided with pad.
Water filling of the present invention have employed the method injected from glass container bottom, avoid the water surface reforming phenomena produced from top water filling, cylinder glass appearance wall is respectively equipped with rule and water yield datum line, adopt audio signal generator, decibelmeter, loudspeaker, changed effective measurement volumes of container by water filling, thus natural frequency is changed.Signal generator of the present invention is for following the trail of the natural frequency of measured object, and decibelmeter detects the change of the loudness that whether resonates for comparing, and achieves the natural frequency carrying out measuring demonstration object in teaching; The minimum excitation density of resonance, and the relation between the size of volume and natural frequency.
Accompanying drawing explanation
Fig. 1 is structural representation of the present invention;
Fig. 2 is the vertical view of Fig. 1;
Fig. 3 is graph of a relation between measuring height of the present invention and natural frequency;
Fig. 4 has novel volume to reduce for this reality and natural frequency increases graph of a relation.
Embodiment
Base plate 1 of the present invention is installed with cylindrical shape transparent glass container 2 respectively, place the support of loudspeaker 4, place the water storage truss 13 of aqua storage tank 12, described glass container 2 and aqua storage tank 12 are placed in the both sides of the support of loudspeaker respectively, described support is by (two columns 6 that be arranged in parallel triangular in shape, single column 7) arrange column composition, column top is installed with supporting plate 3, supporting plate 3 is placed in above glass container 2, supporting plate 3 has the through hole placing loudspeaker 4, rock for preventing loudspeaker 4, pad is provided with in through hole, described through hole is corresponding with described glass container 2 opening, loudspeaker is connected with audio signal generator, described audio signal generator is connected with power supply, decibelmeter 4 is arranged on the glass container 1 of loudspeaker by hanger, for ease of observing and grasping water injection rate, described circle tube glass container 2 sidewall is respectively equipped with rule and water yield datum line, glass container 2 bottom is provided with water inlet, water inlet is connected with aqua storage tank 12 water delivering orifice by water injecting pipeline 10, water in aqua storage tank 12 is by water pump implantation glass container 2, water injection pipe is provided with diffluence pass 5, diffluence pass 5 is connected to dispensing pipe 8, the water inlet that glass container 2 bottom is established, aqua storage tank 12 rising pipe is separately installed with stop valve 11, dispensing pipe 8 is installed fine setting water valve 9 for regulating pondage.
Described clear glass pocket 2 is measured objects, internal diameter 15 centimetres, effective measuring height 20-30 centimetre, and sectional area 176 square centimeters, effective measurement volumes is from 3534.2m
3, 3887.6 m
3, 4241.0 m
3, 4594.5 m
3, 4948.0 m
3to 5301.4 m
3.
The present invention selects circle tube glass container 2 as measured object, utilize audio signal generator as excitation sound source, go to follow the trail of natural frequency, when encouraging sound source identical with the natural frequency of measured object, measured object will be excited to produce and coerce vibration, like this, excitation sound superposes sound with both resonant acoustic of measured object and obviously increases, and empathizes, now, the frequency of signal generator display, is the natural frequency of this object.After this, readjustment excitation sound source amplitude to " 0 " position, is more slowly heightened, certain a bit on there will be sound and amplify suddenly, this some position is exactly the minimum excitation density of resonance.If change the frequency of excitation sound or change volume, the shape conditions of measured object, destroy the important document of resonance, namely encourage sound source not identical with the natural frequency of measured object, do not produce resonance, sympathetic response sound disappears, and sound reduces, thus confirms that object has natural frequency.This instrument also utilizes the method for water filling successively in vessel, change the effective tested volume of water in glass container 2, measure respectively again and find out the different tuning-points (natural frequency) of one group of volume, according to the data that this group records, just can analyze the relation between volume and natural frequency.
concrete method of testing and step:
1, prepare: open audio signal generator preheating 5 minutes, by " frequency adjustment " button as low level, " amplitude " button is adjusted to 0; Open decibelmeter 4(to adjust in normal and Quick Measurement position) and be placed on decibelmeter hanger; 2 kg of water are added by aqua storage tank 12.
2, natural frequency step is tested as follows: open the stop valve 11 on glass container 2 lower water inlet and aqua storage tank 12 rising pipe and water pump, the water in aqua storage tank 12 is filled to datum line 5301.4m by water pump in glass container 2
3, and utilize fine setting water valve 9 round-off error on the isocon on water injecting pipeline 10.Tune up " amplitude " button of signal generator frequently gradually, make to tune up signal generator amplitude frequently progressively to increase, setting output voltage is 3 volts, " frequency adjustment " button of slow tune high frequency signal generator, experience the change (increase of tuning-points loudness) of the underwater sound in glass container 2 at any time simultaneously, observe the change (tuning-points numeral increases) of decibelmeter 4 numeral, if excitation sound source just can find tuning-points from the digital change point of decibelmeter 4 enough greatly simultaneously; After finding tuning-points, turn down or heighten audio signal generator frequency, move apart tuning-points, if loudness reduces, just illustrate that tuning-points is accurate, on the contrary inaccurate.
Or after finding tuning-points, remove loudspeaker, if tuning-points is accurate, then loudness can obviously reduce.If tuning-points is inaccurate, then loudness is without significant change, carries out further determining tuning-points by this step.Tuning-points is exactly the natural frequency of this glass container 2 accurately.
3, minimum exciting power step is tested as follows: after determining tuning-points, " frequency adjustment " button of audio signal generator keeps original position motionless, readjustment audio signal generator " amplitude " button is to lowest order, and then slowly heighten, when reaching minimum exciting power, in glass container 2, the underwater sound increases instantaneously, and the numerical value on decibelmeter 4 is with entering to increase, critical point voltage is now exactly the minimum exciting power of resonance.
4, the relational approach between test volume and natural frequency is as follows: water filling in glass container 2, and according to glass container 2 high scale, water level improves 1 centimetre, and the effective measuring height being equivalent to glass container 2 reduces 1 centimetre, and its volume also reduces 176.7cm accordingly
3, find by the method for test natural frequency and record a tuning-points, carrying out successively as stated above, the natural frequency data of one group of different volumes will be obtained, according to these group data, just can show, be figure, the cheer and bright relation analyzed between volume and natural frequency.
test condition and result
1, condition.Mid-Inner Mongolia, height above sea level 1100 meters, temperature, 21 DEG C time, uses RK1212BL type audio signal generator and TM810M type decibel tester.
2, test result is as following table:
natural frequency test chart
According to upper table, relation between the measuring height of measured object glass container 2 and natural frequency, makes coordinate as Fig. 1:
calculate according to measurement result: the number percent between volume reduction and natural frequency raise makes coordinate as Fig. 2.
analyze and conclusion
According to the data analysis in upper table and Fig. 3-4, draw to draw a conclusion: the first, according to the result that decibelmeter 4 records, loudness difference when resonance and not resonance, about 20 decibels, confirms that object has natural frequency.
The second, by the minimum exciting power method of test test, record driving voltage and do not produce resonance below 1.28 volts, just produce resonance higher than 1.28 volts, illustrate that resonance must have enough excitation densities, this tests minimum exciting power is 0.20 watt.
3rd test size by volume and natural frequency method, obtain the relation between the size of volume and natural frequency: measurement volumes 5301.4 cubic centimetres maximum in table and minimum measurement volumes 3710.7 cubic centimetres are compared, volume reduces 1590.7 cubic centimetres, and natural frequency rising is 315 ﹣ 247 ﹦ 68 hertz, confirm that volume reduces and natural frequency rising.
4th, can find out from Fig. 3 coordinate: between measuring height and natural frequency, relation is: reduce highly gradually and natural frequency increases gradually.Can find out from Fig. 4 coordinate: between measurement volumes and the number percent of natural frequency, variation relation is: volume often reduces by an order of magnitude, and natural frequency raises an order of magnitude accordingly, and slope is substantially linear.
Claims (4)
1. natural frequency measures demonstration device, it is characterized in that, comprise: base plate, audio signal generator, decibelmeter, loudspeaker, described base plate is installed with glass container, described glass container is cylindrical shape, and cylinder glass appearance wall is respectively equipped with rule and water yield datum line, and described glass container bottom is provided with water inlet, water inlet is connected with aqua storage tank water delivering orifice by water injecting pipeline, and aqua storage tank is connected with water pump by pipeline; Described water injection pipe is provided with diffluence pass, diffluence pass is connected to dispensing pipe; Be provided with loudspeaker above glass container, loudspeaker is connected with audio signal generator, and the glass container near loudspeaker is provided with decibelmeter, and described audio signal generator is connected with power supply.
2. natural frequency according to claim 1 measures demonstration device, and it is characterized in that, the water inlet on described glass container and the water delivering orifice on aqua storage tank are separately installed with stop valve, and dispensing pipe is provided with fine setting water valve.
3. natural frequency according to claim 1 measures demonstration device, and it is characterized in that, described decibelmeter is hung on glass container top.
4. natural frequency according to claim 1 measures demonstration device, it is characterized in that, described loudspeaker is placed on support, described support comprises: the column of setting triangular in shape, and be fixedly mounted on the supporting plate at column top, described supporting plate has the through hole placing loudspeaker, described through hole is corresponding with described glass container opening, and through hole is provided with pad.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520140547.1U CN204480559U (en) | 2015-03-12 | 2015-03-12 | Natural frequency measures demonstration device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520140547.1U CN204480559U (en) | 2015-03-12 | 2015-03-12 | Natural frequency measures demonstration device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204480559U true CN204480559U (en) | 2015-07-15 |
Family
ID=53636337
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520140547.1U Active CN204480559U (en) | 2015-03-12 | 2015-03-12 | Natural frequency measures demonstration device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204480559U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104680896A (en) * | 2015-03-12 | 2015-06-03 | 邬博宇 | Measurement demonstrator of inherent frequency |
-
2015
- 2015-03-12 CN CN201520140547.1U patent/CN204480559U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104680896A (en) * | 2015-03-12 | 2015-06-03 | 邬博宇 | Measurement demonstrator of inherent frequency |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105699247B (en) | A kind of synthesis of gas hydrates and decomposition experiment method and experimental system | |
| CN104344886B (en) | A kind of evaluating method of sound-intensity measuring device high sound intensity characteristic | |
| CN106018740B (en) | Hole pressure touching methods demarcate can system | |
| CN106383365B (en) | A method of igneous rock NMR porosity is corrected using plate | |
| CN102572671A (en) | Test method, test tool and test system for microphone tightness | |
| CN103414978A (en) | Sound intensity instrument frequency response calibrating device of acoustic coupler method | |
| CN203299081U (en) | Real-time liquid density measuring instrument | |
| CN204480559U (en) | Natural frequency measures demonstration device | |
| WO2022156460A1 (en) | Method for measuring acoustic parameter of closed small space | |
| CN201788018U (en) | Miniature diaphragm resonance-frequency detector for microphone | |
| CN203178164U (en) | Coal rock porosity-permeability electro-acoustic stress-strain combined measurement device under pressurization heating | |
| CN207074522U (en) | Two-dimentional standing wave resonance demonstrator | |
| CN104680896A (en) | Measurement demonstrator of inherent frequency | |
| CN204924435U (en) | Sound duct is measured in sensitivity of hydrophone low frequency | |
| CN101419108A (en) | Ultrasonic cavitation pressure measuring device and measurement method thereof | |
| CN104864943B (en) | A kind of calibrating installation and method of liquid level tester | |
| CN206853754U (en) | A kind of Multi-functional slope culture medium configuring frame | |
| CN201122140Y (en) | Yang elasticity modulus measurer | |
| CN206132767U (en) | Concrete expansion rate apparatus | |
| CN211148387U (en) | Device for testing dynamic characteristics of rock-soil body | |
| CN201166933Y (en) | Experiment instrument for measuring acoustic velocity | |
| CN110164265B (en) | Vertical longitudinal wave standing wave experiment measurement device and method | |
| CN204462415U (en) | A kind of device utilizing hydrostatic pressure to measure acceleration of gravity | |
| CN209706913U (en) | Adjustable groundwater level monitoring device | |
| CN107846652A (en) | Diffuser resonant frequency determines devices and methods therefor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |