CN202974385U - Capacitance liquid level transmitter - Google Patents
Capacitance liquid level transmitter Download PDFInfo
- Publication number
- CN202974385U CN202974385U CN 201220691087 CN201220691087U CN202974385U CN 202974385 U CN202974385 U CN 202974385U CN 201220691087 CN201220691087 CN 201220691087 CN 201220691087 U CN201220691087 U CN 201220691087U CN 202974385 U CN202974385 U CN 202974385U
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- Prior art keywords
- metal
- liquid level
- level transmitter
- circuit plate
- rod
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Abstract
The utility model provides a capacitance liquid level transmitter which comprises a measuring rod, a compensation circuit board and an amplifying circuit board. The measuring rod comprises a metal outer rod and a metal inner rod which is connected in the metal outer rod in a sleeved mode. The length of the metal outer rod and the metal inner rod ranges from 50mm to 450mm. The area of sections of the metal outer rod and the metal inner rod ranges from 10 mm2 to 700 mm2. A liquid containing cavity is formed between the metal outer rod and the metal inner rod. The linearity range of the compensation board is from -1% to 1% FS and the temperature compensation range is from 0 DEC G to 80 DEC G. Amplification times of the amplifying circuit board is more than 1000. The capacitance liquid level transmitter can measure small capacity and sallow liquid level.
Description
Technical field
The utility model relates to sensor field, particularly a kind of capacitive liquid level transmitter.
Background technology
Fluid level transmitter is to the extension of pressure unit technology and development, in the linear principle of pressure that differing heights produces, realizes that volume, the liquid to water, oil and pastel is high, Measurement accuracy and the transmission of weight according to the liquid of different specific weight.Owing to being applicable to continuous detecting under the mal-conditions such as High Temperature High Pressure, deep-etching, easily crystallization, easy obstruction, capacitive liquid level transmitter plays an important role aspect level gauging.Capacitive liquid level transmitter is based on survey fluid pressure and the proportional principle of the height of this liquid, is about to capacitance variations that two Metallic rod produce and is converted to electric signal and measures in liquid.Capacitive liquid level transmitter is widely used in the level gauging of the medium of petrochemical complex, metallurgy, electric power, pharmacy, water supply and sewage, field of Environment Protection.
Yet the container that existing capacitive liquid level transmitter is measured is larger, and fathoms all more than 0.5 meter, can't satisfy the measurement of the liquid level (being shallow liquid level) lower than 0.5 meter.In actual production process, the dielectric capacity of some equipment is less and liquid level is more shallow and be badly in need of measurement.Thereby study and develop a kind of capacitive liquid level transmitter tool that is applicable to low capacity and shallow liquid level and be of great significance.
The utility model content
The technical problems to be solved in the utility model is can't realize the defective of low capacity and shallow level gauging for the capacitive liquid level transmitter that overcomes prior art, and a kind of capacitive liquid level transmitter that can measure low capacity and shallow liquid level is provided.
The utility model is to solve above-mentioned technical matters by following technical proposals:
A kind of capacitive liquid level transmitter, its characteristics are, this fluid level transmitter includes a sounding rod, a compensating circuit plate and a magnification circuit plate, this sounding rod comprises that the outer bar and of a metal is socketed on the inner metal rod in the outer bar of this metal, the length of the outer bar of this metal and this inner metal rod is 50mm to 450mm, and the sectional area of the outer bar of this metal and this inner metal rod is 10mm
2To 700mm
2, being formed with a liquid accommodating cavity between the outer bar of this metal and this inner metal rod, the linearity scope of this compensating circuit plate is 0 ℃ to 80 ℃ for ± 1%FS and temperature compensation range, the enlargement factor of this magnification circuit plate is higher than 1000.
Preferably, the outer bar of this metal has a liquid feeding end and one first collection terminal, offers a plurality of inlet openings on this liquid feeding end, offers a plurality of vent ports on this first collection terminal, those inlet openings and those vent ports all are connected with this liquid accommodating cavity.Those vent ports are used for reducing the air pressure in this liquid accommodating cavity, with convenient follow-up testing liquid continue pour into.
Preferably, this inner metal rod has a stiff end and one second collection terminal, this stiff end is separated mutually by an insulator foot and this liquid feeding end, and this liquid feeding end place is sealed with an insulating end plate.The effect of this insulator foot is to keep apart this stiff end and this liquid feeding end, in order to form electric capacity between the two, the relative position of this stiff end and this liquid feeding end can also be fixed in addition.This insulating end plate has the double action that prevents that this insulator foot slippage and prevention dust from entering this liquid accommodating cavity.
Preferably, this first collection terminal is connected with a metal base, has a groove in this metal base, be provided with a metal end plate in this groove, this metal end plate fixes by an insulating washer and this groove internal face, and this second collection terminal passes this insulating washer hole and is electrically connected to this metal end plate.Can stop this metal end plate and this metal base of this insulating washer discharge mutually, so that this inner metal rod is suspended in the groove of the outer bar of this metal, keep the electricity isolation of this first collection terminal and this second collection terminal.
Preferably, the end of this metal base is fixed with an accommodating pedestal, this compensating circuit plate and this magnification circuit plate are arranged in this accommodating pedestal, this compensating circuit plate is electrically connected to this metal base by one first electrode pin, and this compensating circuit plate also is electrically connected to this second collection terminal by one second electrode pin.The effect of this compensating circuit plate and this magnification circuit plate is to electric signal amplification, filtering and oscillation-damped, and gets rid of the ambient temperature variation to the impact of electric signal.In the situation that shallow liquid level and low capacity, the numerical value of electric capacity is very little, thereby the magnification circuit plate of high-precision compensating circuit plate and high-amplification-factor is particularly necessary.
Preferably, the end part seal of this accommodating pedestal has a gland bonnet, sealing covers and is fixed with a plug connector, this plug connector is electrically connected to the outlet line of this magnification circuit plate.This plug connector is used for being electrically connected to display screen or instrument, in order to show the level gauging value.
Preferably, be provided with a stopper slot in this insulating washer, this metal end plate is installed in this stopper slot,
And fix by an insulcrete and a plurality of clamp nut.
Preferably, the outer bar of this metal and this inner metal rod be hollow cylinder, the external diameter of the outer bar of this metal and this inner metal rod is 4mm to 20mm.
Preferably, this magnification circuit plate comprises a capacitance detecting chip, a controller and a loop service chip that is electrically connected to successively.
Positive progressive effect of the present utility model is: length and the cross section of the outer bar of this metal are all less, therefore the equipment of the shallow liquid level of very suitable measurement and low capacity.In addition, by the outer bar of this metal and this inner metal rod being made into the version of mutual socket, make the variation range of capacitance values increase, this compensating circuit plate of while combined high precision and this magnification circuit plate of high-amplification-factor, this capacitive liquid level transmitter can amplify faint capacitance variations signal and export.
Description of drawings
Fig. 1 is the cut-open view of the capacitive liquid level transmitter of the utility model preferred embodiment.
Fig. 2 is the A section enlarged drawing of capacitive liquid level transmitter in Fig. 1.
Fig. 3 is the B section enlarged drawing of capacitive liquid level transmitter in Fig. 1.
Fig. 4 is the structural representation of the magnification circuit plate of capacitive liquid level transmitter in Fig. 1.
Description of reference numerals:
Plug connector: 1 screw: 2
Gland bonnet: 3 magnification circuit plates: 4
Screw: 5 compensating circuit plates: 6
Cylindricality packing ring: 7 accommodating pedestals: 8
The first electrode pin: 9 clamp nuts: 10
Insulcrete: 11 metal end plates: 12
Insulating washer: 13 second electrode pin: 14
Metal base: 15 inner metal rods: 16
Isolating shrinkable tube: the outer bar of 17 metals: 18
Insulator foot: 19 insulating end plates: 20
Inlet opening: 21 vent ports: 22
Liquid accommodating cavity: 23 liquid feeding ends: 24
The first collection terminal: 25 stiff ends: 26
The second collection terminal: 27 grooves: 28
Capacitance detecting chip: 41 controllers: 42
Loop service chip: 43
Embodiment
The below lifts a preferred embodiment, and comes by reference to the accompanying drawings the clearer the utility model that intactly illustrates.
As shown in Figure 1, the capacitive liquid level transmitter of the present embodiment includes a sounding rod, this sounding rod comprises the inner metal rod 16 of the outer bar 18 of the metal of a hollow cylinder and a hollow cylinder, this inner metal rod 16 is socketed in the outer bar 18 of this metal, and be formed with a liquid accommodating cavity 23 between the two, the outer bar 18 of this metal has a liquid feeding end 24 and one first collection terminal 25, offer four inlet openings 21 on this liquid feeding end 24, offer four vent ports 22 on this first collection terminal 25, those inlet openings 21 and those vent ports 22 all are connected with this liquid accommodating cavity 23.
During use, vertically insert sounding rod in testing liquid, testing liquid flows into this liquid accommodating cavity 23 from those inlet openings 21, and this moment, those vent ports 22 were discharged the air that equals to pour into liquid volume, to reduce air pressure in this liquid accommodating cavity 23 convenient follow-up testing liquid continue pour into.
Because length and the external diameter of the outer bar 18 of this metal is respectively 140mm and 16mm, therefore be particularly suitable for the measurement of the equipment of low capacity and shallow liquid level.The length of this inner metal rod 16 and external diameter are respectively 160mm and 4mm.During production, lengthening that can also be suitable according to the actual measurement operating mode or shorten the length of the outer bar of this metal and this inner metal rod.This inner metal rod 16 has a stiff end 26 and one second collection terminal 27.
As shown in Figure 2, this stiff end 26 is separated with this liquid feeding end 24 mutually by an insulator foot 19, and this liquid feeding end 24 places are sealed with an insulating end plate 20.This insulator foot 19 is used for this stiff end 26 and this liquid feeding end 24 are kept apart, and stops both electric connections in order to form electric capacity.This insulating end plate 20 is used for this liquid accommodating cavity 23 of sealing, has these insulator foot 19 slippages and the effect that stops dust to enter this liquid accommodating cavity 23 of preventing.Please in conjunction with Fig. 1, this insulator foot 19 and this insulating end plate 20 can be more
Good this inner metal rod 16 and the outer bar 18 of this metal fixed, during actual production, this insulator foot 19 and this insulating end plate 20 all can save.
As shown in Figure 3, this first collection terminal 25 is connected with a metal base 15, has a groove 28 in this metal base 15, be provided with a metal end plate 12 in this groove 28, this metal end plate 12 fixes with these groove 28 internal faces by an insulating washer 13, and this second collection terminal 27 passes the hole of this insulating washer 13 and is electrically connected to this metal end plate 12.Be provided with a stopper slot in this insulating washer 13, this metal end plate 12 is installed in this stopper slot, and fixing by an insulcrete 11 and a plurality of clamp nut 10.The end of this metal base 15 is fixed with an accommodating pedestal 8, one compensating circuit plate 6 and a magnification circuit plate 4 are arranged in this accommodating pedestal 8 by a screw 5 and a cylindricality packing ring 7, this compensating circuit plate 6 is electrically connected to this metal base 15 by one first electrode pin 9, and this compensating circuit plate 6 also is electrically connected to this second collection terminal 27 by one second electrode pin 14.
The end part seal of this accommodating pedestal 8 has a gland bonnet 3, is fixed with a plug connector 1 by two pieces of screws 2 on sealing lid 3, and this plug connector 1 is electrically connected to the outlet line of this magnification circuit plate 4.This plug connector 1 is used for being electrically connected to display screen or instrument, in order to show the level gauging value.In order to protect this inner metal rod 16, the outer covering one deck of this inner metal rod 16 isolating shrinkable tube 17, the material of this isolating shrinkable tube 17 can be teflon.
As shown in Figure 3-4, the linearity scope of this compensating circuit plate 6 is ± 0.05%FS(Full Scale, full scale), and temperature compensation range is 0 ℃ to 80 ℃, the enlargement factor of this magnification circuit plate 4 is 1500.Due to the liquid level degree of depth lower than 0.5 meter (being shallow liquid level), thereby the numerical value of electric capacity is less, need to guarantee the electrical parameter of this compensating circuit plate 6 and this magnification circuit plate 4, to electric signal amplification, filtering and oscillation-damped, and get rid of the ambient temperature variation to the impact of electric signal.Therefore only on the basis that dimensional structure and the metering circuit Accuracy Matching of sounding rod are coordinated, can realize the measurement to shallow liquid level and low capacity instrument.
Comprise a capacitance detecting chip 41, a controller 42 and a loop service chip 43 that is electrically connected to successively on this magnification circuit plate 4 is concrete, this loop service chip 43 is used to this controller 42 power supplies, this capacitance detecting chip 41 can be the ZMDI311210 chip, this controller 42 can be the MSP430F14 chip, and this loop service chip 43 can be the AD5421 chip.The ZMDI311210 chip is Germany
The electric capacity of 2pF to 260pF can be measured in the commercially available prod of ZMDI company, and data updating rate is the 18mS(millisecond), measuring accuracy is the 14bit(bit).The MSP430F14 chip is the commercially available prod of Texas Instruments.AD5421 is the commercially available prod of U.S. AD company.During actual production, can use the equal or more high-precision chip that other company produces to replace said chip, in order to make the magnification circuit plate that is fit to the test operating mode.
During use, as shown in Fig. 1-4, sounding rod is vertically inserted in testing liquid, testing liquid flows into this liquid accommodating cavity 23 from those inlet openings 21.Because the specific inductive capacity of testing liquid is different from the specific inductive capacity of the above gas of liquid level, when liquid level raise, the specific inductive capacity between the outer bar 18 of this inner metal rod 16 and this metal increased thereupon, thereby capacitance between the two is also larger.In like manner, when liquid level reduced, capacitance reduced gradually.This sounding rod is used for the liquid level variable signal in liquid accommodating cavity 23 is converted into the capacitance variations signal; This compensating circuit plate 6 is used for the temperature compensation of capacitance variations signal and linear revise; Signal after this magnification circuit plate 4 is used for this compensating circuit plate is processed amplifies and exports.
Although more than described embodiment of the present utility model, it will be understood by those of skill in the art that these only illustrate, protection domain of the present utility model is limited by appended claims.Those skilled in the art can make various changes or modifications to these embodiments under the prerequisite that does not deviate from principle of the present utility model and essence, but these changes and modification all fall into protection domain of the present utility model.
Claims (9)
1. capacitive liquid level transmitter, it is characterized in that, this fluid level transmitter includes a sounding rod, a compensating circuit plate and a magnification circuit plate, this sounding rod comprises that the outer bar and of a metal is socketed on the inner metal rod in the outer bar of this metal, the length of the outer bar of this metal and this inner metal rod is 50mm to 450mm, and the sectional area of the outer bar of this metal and this inner metal rod is 10mm
2To 700mm
2, being formed with a liquid accommodating cavity between the outer bar of this metal and this inner metal rod, the linearity scope of this compensating circuit plate is 0 ℃ to 80 ℃ for ± 1%FS and temperature compensation range, the enlargement factor of this magnification circuit plate is higher than 1000.
2. capacitive liquid level transmitter as claimed in claim 1, it is characterized in that, the outer bar of this metal has a liquid feeding end and one first collection terminal, offer a plurality of inlet openings on this liquid feeding end, offer a plurality of vent ports on this first collection terminal, those inlet openings and those vent ports all are connected with this liquid accommodating cavity.
3. capacitive liquid level transmitter as claimed in claim 2, is characterized in that, this inner metal rod has a stiff end and one second collection terminal, and this stiff end is separated mutually by an insulator foot and this liquid feeding end, and this liquid feeding end place is sealed with an insulating end plate.
4. capacitive liquid level transmitter as claimed in claim 3, it is characterized in that, this first collection terminal is connected with a metal base, has a groove in this metal base, be provided with a metal end plate in this groove, this metal end plate fixes by an insulating washer and this groove internal face, and this second collection terminal passes this insulating washer hole and is electrically connected to this metal end plate.
5. capacitive liquid level transmitter as claimed in claim 4, it is characterized in that, the end of this metal base is fixed with an accommodating pedestal, this compensating circuit plate and this magnification circuit plate are arranged in this accommodating pedestal, this compensating circuit plate is electrically connected to this metal base by one first electrode pin, and this compensating circuit plate also is electrically connected to this second collection terminal by one second electrode pin.
6. capacitive liquid level transmitter as claimed in claim 5, is characterized in that, the end part seal of this accommodating pedestal has a gland bonnet, and sealing covers and is fixed with a plug connector, and this plug connector is electrically connected to the outlet line of this magnification circuit plate.
7. capacitive liquid level transmitter as claimed in claim 4, is characterized in that, is provided with a stopper slot in this insulating washer, and this metal end plate is installed in this stopper slot, and fix by an insulcrete and a plurality of clamp nut.
8. capacitive liquid level transmitter as claimed in claim 1, is characterized in that, the outer bar of this metal and this inner metal rod are hollow cylinder, and the external diameter of the outer bar of this metal and this inner metal rod is 4mm to 20mm.
9. capacitive liquid level transmitter as described in any one in claim 1-8, is characterized in that, this magnification circuit plate comprises a capacitance detecting chip, a controller and a loop service chip that is electrically connected to successively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220691087 CN202974385U (en) | 2012-12-13 | 2012-12-13 | Capacitance liquid level transmitter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220691087 CN202974385U (en) | 2012-12-13 | 2012-12-13 | Capacitance liquid level transmitter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202974385U true CN202974385U (en) | 2013-06-05 |
Family
ID=48515444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220691087 Expired - Fee Related CN202974385U (en) | 2012-12-13 | 2012-12-13 | Capacitance liquid level transmitter |
Country Status (1)
| Country | Link |
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| CN (1) | CN202974385U (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103353326A (en) * | 2013-07-01 | 2013-10-16 | 苏州赛智达智能科技有限公司 | Double-tube capacitive type liquid level sensor capable of preventing short circuiting |
| CN103353325A (en) * | 2013-07-01 | 2013-10-16 | 苏州赛智达智能科技有限公司 | Three-tube capacitive type liquid level sensor capable of preventing short circuiting |
| CN103471681A (en) * | 2013-09-29 | 2013-12-25 | 湖南宇航科技有限公司 | Capacitance type oil level sensor filling method |
| CN103868567A (en) * | 2012-12-13 | 2014-06-18 | 上海朝辉压力仪器有限公司 | Capacitance liquid level transmitter |
| CN108120490A (en) * | 2018-01-11 | 2018-06-05 | 上海汽车集团股份有限公司 | Caravan water tank water-level detecting device and method |
| US10493766B2 (en) | 2016-04-21 | 2019-12-03 | Hewlett-Packard Development Company, L.P. | Fluid level sensing with protective member |
| US11046084B2 (en) | 2016-04-21 | 2021-06-29 | Hewlett-Packard Development Company, L.P. | Liquid level sensing |
-
2012
- 2012-12-13 CN CN 201220691087 patent/CN202974385U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103868567A (en) * | 2012-12-13 | 2014-06-18 | 上海朝辉压力仪器有限公司 | Capacitance liquid level transmitter |
| CN103353326A (en) * | 2013-07-01 | 2013-10-16 | 苏州赛智达智能科技有限公司 | Double-tube capacitive type liquid level sensor capable of preventing short circuiting |
| CN103353325A (en) * | 2013-07-01 | 2013-10-16 | 苏州赛智达智能科技有限公司 | Three-tube capacitive type liquid level sensor capable of preventing short circuiting |
| CN103471681A (en) * | 2013-09-29 | 2013-12-25 | 湖南宇航科技有限公司 | Capacitance type oil level sensor filling method |
| US10493766B2 (en) | 2016-04-21 | 2019-12-03 | Hewlett-Packard Development Company, L.P. | Fluid level sensing with protective member |
| US11046084B2 (en) | 2016-04-21 | 2021-06-29 | Hewlett-Packard Development Company, L.P. | Liquid level sensing |
| CN108120490A (en) * | 2018-01-11 | 2018-06-05 | 上海汽车集团股份有限公司 | Caravan water tank water-level detecting device and method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| 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: 20130605 Termination date: 20211213 |