CN201233264Y - Liquid level sensor with thermister probe and liquid level measuring set thereof - Google Patents
Liquid level sensor with thermister probe and liquid level measuring set thereof Download PDFInfo
- Publication number
- CN201233264Y CN201233264Y CNU2008200994623U CN200820099462U CN201233264Y CN 201233264 Y CN201233264 Y CN 201233264Y CN U2008200994623 U CNU2008200994623 U CN U2008200994623U CN 200820099462 U CN200820099462 U CN 200820099462U CN 201233264 Y CN201233264 Y CN 201233264Y
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- liquid level
- level sensor
- thermistor
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- amplification circuit
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Abstract
The utility model relates to a liquid level sensor with thermosensitive resistors as probes and a liquid level measurement device thereof. The liquid level sensor is a resistor measurement unit with an alternating-current bridge structure, and resistors to be measured are the thermosensitive resistors as the probes of the liquid level sensor. The liquid level measurement device comprises the liquid level sensor, a signal amplification circuit, a display circuit and a voltage regulator circuit; wherein, the signal amplification circuit is connected with the liquid level sensor; and the display circuit and the voltage regulator circuit are connected with the signal amplification circuit. The corresponding thermosensitive resistors in a plurality of same liquid level measurement devices are respectively placed at the highest liquid level line and different positions below the highest liquid level line on the sidewall of a liquid container. The utility model has the advantages of strong visibility and reliable measured data. The signal outputted by the signal amplification circuit can also be used as a warning signal for the high limit of liquid level as well as a control signal for an electromagnetic valve. In addition, all the electronic elements are regular electronic elements, so production can be easily organized.
Description
Technical field
The utility model relates to liquid level sensor and liquid level emasuring device thereof.
Background technology
Liquid level is meant the height of liquid medium liquid level in the liquid container.The purpose of level gauging mainly is to predict the memory space of liquid in the liquid container (water, oil or other liquid mediums), so that the liquid in the liquid container is monitored to guarantee normal productive process and device security.Therefore, in production run and plant engineering field, liquid level is a crucial parameter.Level gauging has very long history, is also accumulating considerable experience aspect measuring method and the surveying instrument making.The a variety of liquid level emasuring devices of industrial use can be divided into direct-reading, floatage-type, static pressure type, condenser type, optical fiber type, laser type, nuclear radiation formula by principle of work.Wherein method fairly simple, be to utilize with the glass tube of fluid to be measured container or equipment bypass or the glass tube of crack to show liquid level intuitively, but this method can only indicate on the spot, can't realize the signal is far passed and problem such as control automatically.
In addition, in the Building Environment and Equipment Engineering field, often relate to Residual oil oil level (Residual oil surplus) the detection problem of many jars, tower, equipment etc.Because the volume of equipment is more and more littler, so communicating pipe is very thin sometimes, existing many oil-level measurement methods and device thereof all are restricted, some kapillary positions particularly, and many existing liquid level sensors can't be installed at all.Though what have can install and measure well, its installation cost is again than higher.
The utility model content
First purpose of the present utility model is, provides a kind of signal can transmit at a distance, can be installed in the less liquid container, and liquid level sensor with low cost.
Second purpose of the present utility model is that a kind of liquid level emasuring device that uses above-mentioned liquid level sensor is provided.
For realizing first purpose, it is the liquid level sensor of thermistor that a kind of probe is provided.This liquid level sensor is the resistance test device that testing resistance, zero-regulator resistor, two fixed resistances is arranged and be with the alternating current bridge structure of AC power.In the utility model, testing resistance is the thermistor as the liquid level sensor probe.Be in series with each electric capacity, an end ground connection of AC power on the brachium pontis of this thermistor and on the brachium pontis of zero-regulator resistor respectively.Node, two joining nodes of fixed resistance brachium pontis that this thermistor brachium pontis and zero-regulator resistor brachium pontis connect are the signal output part of this liquid level sensor.This thermistor with can be by the liquid-immersed state of liquid level to be measured, be placed on the sidewall of this liquid container.
For realizing second purpose, provide a kind of like this liquid level emasuring device.This measurement mechanism includes above-mentioned probe and is the liquid level sensor of thermistor, the signal amplification circuit that is connected with the signal output part node of this liquid level sensor, the display circuit that is connected with the amplifying signal output terminal of this signal amplification circuit and the mu balanced circuit that power supply is provided for liquid level sensor, signal amplification circuit and display circuit.The thermistor of the respective amount in this several same liquid level emasuring device is placed in the highest liquid level line on the sidewall of liquid container and following diverse location place thereof respectively.
From the scheme that realizes first purpose as can be seen, thermistor as this liquid level sensor probe be " with can be by the liquid-immersed state of liquid level to be measured, be placed on the sidewall of this liquid container ", that is to say, liquid level raises and reduces, and just can cause this thermistor or is immersed in the liquid or is exposed in the interior upper space (being mainly air) of liquid container.(it is poor that air conducts heat because liquid-to-air has the difference of conducting heat quite significantly, the thermistor quick heating), cause the resistance of thermistor to have like this,, just can judge the liquid level of liquid in the liquid container by detection to the change in resistance of thermistor than big difference.Compare with existing liquid level sensor, adopt thermistor following advantage to be arranged as the liquid level sensor of probe:
1, volume is little, the liquid level in energy measurement space, cavity and the tubule;
2, highly sensitive;
3, easy to use;
4, low in energy consumption;
5, response fast (thermal inertia is little);
6, realize telemeasurement and control easily;
7, with low cost.
As can be seen, element, signal amplification circuit, display circuit and mu balanced circuit thereof in the liquid level sensor of the thermistor in the utility model, formation bridge structure all do not have special requirement from the scheme that realizes second purpose.That is to say that all elements and the circuit product of forming this technical scheme product all can adopt existing conventional products, in view of, can be a lot of for the existing product that one of ordinary skill in the art select, be not further described at this.From this programme described " thermistor of the respective amount this several same liquid level emasuring device; be placed in the highest liquid level line on the sidewall of liquid container and following diverse location place thereof respectively ", only to find out, the utility model can measure each different liquid level, in practice, should determine the thermistor of this liquid level emasuring device and respective amount thereof according to the specific requirement of measuring.
Carrying out liquid level emasuring device when debugging,, allow thermistor in each liquid level sensor all with during air contacts at first the liquid emptying in the liquid container; The AC high frequency power source of utilizing power circuit to provide heats to the thermistor in each liquid level sensor, after treating that its resistance no longer changes, adjust the zero-regulator resistor in the liquid level sensor, even bridge balance, adjust signal amplification circuit and make its no signal output, this moment, display circuit did not show (in embodiment, promptly LED is for extinguishing state).So far, each liquid level emasuring device debugging finishes, and begins to carry out the supervision and the measurement of liquid level.When adding liquid, cause be positioned at following a certain thermistor and be immersed in liquid level after, as previously mentioned, thermistor is sharply lowered the temperature, and resistance changes, and electric bridge is with imbalance, amplify output signal by signal amplification circuit, by display circuit real liquid level is shown at last.
Compare with existing liquid level emasuring device, the liquid level emasuring device of this programme has stronger intuitive, the advantage of reliable measuring data.Simultaneously, the output of the amplifying signal of signal amplification circuit can also be made liquid level upper limit alarm signal, also can make the control signal of solenoid valve, and controlled liquid level is changed in the set-point scope, realizes position formula control.In addition, the utility model also has used electronic component to be the conventional electrical element, easily the characteristics of tissue production.
The utility model is described in further detail below in conjunction with the drawings and specific embodiments.
Description of drawings
Fig. 1 is the circuit theory diagrams of a liquid level emasuring device of the present utility model
Fig. 2 is the sensor probe (thermistor) in several the utility model and the theory diagram of corresponding liquid level emasuring device thereof
Fig. 3 is the scheme of installation of the sensor probe (thermistor) in several the utility model
Fig. 4 is the display panel synoptic diagram that the light emitting diode in several the utility model constitutes
Embodiment
A kind of probe is the liquid level sensor (with reference to the circuit diagram that is labeled as among the figure 1 in 1 the frame of broken lines) of thermistor.This liquid level sensor is the resistance test device that the alternating current bridge structure of testing resistance, zero-regulator resistor R2, two fixed resistances (R3, R4) and band AC power S is arranged.In the utility model, testing resistance is the thermistor Rrm as liquid level sensor 1 probe.Be in series with each electric capacity (C1, C2), the end ground connection of AC power S on the brachium pontis of this thermistor Rrm and on the brachium pontis of zero-regulator resistor R2 respectively.Node U1, the joining node U2 of two fixed resistances (R3, R4) brachium pontis that this thermistor Rrm brachium pontis and zero-regulator resistor R2 brachium pontis connect are the signal output part of this liquid level sensor 1.This thermistor Rrm with can be by the liquid-immersed state of liquid level to be measured, be placed on the sidewall of this liquid container 4.
A kind of liquid level emasuring device (with reference to figure 1,2).This measurement mechanism includes the liquid level sensor 1 that above-mentioned probe is a thermistor, the signal amplification circuit 2 that is connected with the signal output part node (U1, U2) of this liquid level sensor 1, the display circuit 3 that is connected with the amplifying signal output terminal UO of this signal amplification circuit 2 and the mu balanced circuit that power supply is provided for liquid level sensor 1, signal amplification circuit 2 and display circuit 3.The thermistor Rrm of the respective amount in this several same liquid level emasuring device is placed in the highest liquid level line 5 on the sidewall of described liquid container 4 and following diverse location place (with reference to figure 2,3,4) thereof respectively.
More particularly, in this embodiment (with reference to the circuit diagram that is labeled as among the figure 1 in 2 the frame of broken lines), signal amplification circuit 2 comprises the voltage follower that is made of two identical operation amplifiers (A1, A2) and the differential amplifier that is made of an operational amplifier A 3 that is connected with this voltage follower.Two power inputs of this voltage follower respectively with the both positive and negative polarity of stabilized voltage supply (+VCC ,-VCC) be connected, the electrode input end of two operational amplifiers (A1, A2) in this voltage follower is connected with the signal output part node (U1, U2) of liquid level sensor 1 respectively; Two power inputs of this differential amplifier respectively with the both positive and negative polarity of stabilized voltage supply (+VCC ,-VCC) be connected, the output terminal of the operational amplifier A 3 in this differential amplifier is amplifying signal output terminal UO.Be connected to zero potentiometer RW on the operational amplifier A 3 in differential amplifier, with before the signal output part node (U1, U2) of liquid level sensor 1 is connected, by regulating zero potentiometer RW, the output voltage that makes amplifying signal output terminal UO is zero.In this embodiment, it is the operational amplifier (also not getting rid of other alternative elements) of LF353 that two operational amplifiers (A1, A2) of formation voltage follower can adopt model; It is the operational amplifier (also not getting rid of other alternative elements) of OP-07 that operational amplifier A 3 in the formation differential amplifier can adopt model.
In this embodiment (with reference to the circuit diagram that is labeled as among the figure 1 in 3 the frame of broken lines), display circuit 3 is for including the display circuit of LED and reverser IC1a.The output terminal UO of signal amplification circuit 2 is connected with the input end of this reverser IC1a; Power input in this display circuit 3 is connected with positive pole of stabilized voltage supply output terminal+VCC.
In Fig. 1, resistance R 5, R6, R7, R8 and zero potentiometer RW and operational amplifier A 3 have constituted differential amplifier; What be labeled as R9, R10, R11 is the current-limiting resistance that constitutes display circuit 3, plays the effect of protection LED and reverser IC1a.In view of only with regard to signal amplification circuit 2 and display circuit 3, be well-known to those skilled in the art, so, be not described in further detail at this.
The concrete installation way of this liquid level emasuring device is: according to other conditioned disjunction requirements, thermistor Rrm is arranged in order from top to bottom is installed in one and measures on the plate 6, and this measurement plate 6 is fixed on the inwall (with reference to figure 2,3) of liquid container 4; Be installed in (with reference to the figure 4) on the display panel of the LED correspondence of respective amount.Represent to also have certain liquid level by LED is luminous.Liquid level is when a certain height, and liquid level changes with the thermistor Rrm resistance of lower part, and electric bridge is in non-equilibrium state, and the following respective leds LED of liquid level position is lighted, and the height of being lighted by LED is represented the height of liquid level.
Claims (4)
1, probe is the liquid level sensor of thermistor, this liquid level sensor is the resistance test device that the alternating current bridge structure of testing resistance, zero-regulator resistor (R2), two fixed resistances (R3, R4) and band AC power (S) is arranged, it is characterized in that described testing resistance is the thermistor (Rrm) as liquid level sensor (1) probe; Be in series with each electric capacity (C1, C2), an end ground connection of described AC power (S) on the brachium pontis of this thermistor (Rrm) and on the brachium pontis of described zero-regulator resistor (R2) respectively; Node (U1), two fixed resistance joining nodes of (R3, R4) brachium pontis (U2) that this thermistor (Rrm) brachium pontis and zero-regulator resistor (R2) brachium pontis connect are the signal output part of this liquid level sensor (1); This thermistor (Rrm) with can be by the liquid-immersed state of liquid level to be measured, be placed on the sidewall of this liquid container (4).
2, a kind of liquid level emasuring device, it is characterized in that this measurement mechanism includes the described liquid level sensor of claim 1 (1), the signal amplification circuit (2) that is connected with the signal output part node (U1, U2) of this liquid level sensor (1), the display circuit (3) that is connected with the amplifying signal output terminal (U0) of this signal amplification circuit (2) and the mu balanced circuit of power supply is provided for liquid level sensor (1), signal amplification circuit (2) and display circuit (3); The thermistor (Rrm) of the respective amount in this several same liquid level emasuring device is placed in the highest liquid level line (5) on the sidewall of described liquid container (4) and following diverse location place thereof respectively.
3, liquid level emasuring device according to claim 2, it is characterized in that described signal amplification circuit (2) comprises voltage follower that is made of two identical operation amplifiers (A1, A2) and the differential amplifier by an operational amplifier (A3) formation that is connected with this voltage follower; Two power inputs of this voltage follower respectively with the both positive and negative polarity of stabilized voltage supply (+VCC ,-VCC) be connected, the electrode input end of two operational amplifiers (A1, A2) in this voltage follower is connected with the signal output part node (U1, U2) of liquid level sensor (1) respectively; Two power inputs of this differential amplifier respectively with the both positive and negative polarity of stabilized voltage supply (+VCC ,-VCC) be connected, the output terminal of the operational amplifier in this differential amplifier (A3) is amplifying signal output terminal (U0); Be connected to zero potentiometer (RW) on the operational amplifier in this differential amplifier (A3), with before the signal output part node (U1, U2) of liquid level sensor (1) is connected, regulate zero potentiometer (RW) by this, making amplifying signal output terminal (U0) output voltage is zero.
According to claim 2 or 3 described liquid level emasuring devices, it is characterized in that 4, described display circuit (3) is for including the display circuit of light emitting diode (LED) and reverser (ICla); The output terminal (U0) of described signal amplification circuit (2) is connected with the input end of this reverser (ICla); Power input in this display circuit (3) and positive pole of stabilized voltage supply output terminal (+VCC) be connected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200994623U CN201233264Y (en) | 2008-07-16 | 2008-07-16 | Liquid level sensor with thermister probe and liquid level measuring set thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200994623U CN201233264Y (en) | 2008-07-16 | 2008-07-16 | Liquid level sensor with thermister probe and liquid level measuring set thereof |
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| Publication Number | Publication Date |
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| CN201233264Y true CN201233264Y (en) | 2009-05-06 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNU2008200994623U Expired - Fee Related CN201233264Y (en) | 2008-07-16 | 2008-07-16 | Liquid level sensor with thermister probe and liquid level measuring set thereof |
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| CN (1) | CN201233264Y (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102107716A (en) * | 2010-11-25 | 2011-06-29 | 中国海洋石油总公司 | Liquid tank pool test monitoring device of large-scale liquefied petroleum and natural gas carrier |
| CN102539286A (en) * | 2011-11-16 | 2012-07-04 | 山东轻工业学院 | Automatic timing device and timing method of capillary viscometer |
| CN104568053A (en) * | 2014-12-11 | 2015-04-29 | 中国核电工程有限公司 | Self-heating differential thermoresistor liquid level sensor and liquid level measurement method thereof |
| CN104568054A (en) * | 2014-12-11 | 2015-04-29 | 中国核电工程有限公司 | Liquid level sensor of heating type differential thermal resistor and liquid level measuring method thereof |
| CN104608497A (en) * | 2015-01-20 | 2015-05-13 | 重庆工商大学 | Automatic ink supply system applied to printer |
| CN109892310A (en) * | 2019-04-04 | 2019-06-18 | 江阴职业技术学院 | A kind of adjustable crops field medicine liquid spray device |
| CN111637951A (en) * | 2020-05-27 | 2020-09-08 | 广州大学 | Photosensitive emulsion liquid level detection device and atomization method |
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2008
- 2008-07-16 CN CNU2008200994623U patent/CN201233264Y/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102107716A (en) * | 2010-11-25 | 2011-06-29 | 中国海洋石油总公司 | Liquid tank pool test monitoring device of large-scale liquefied petroleum and natural gas carrier |
| CN102539286A (en) * | 2011-11-16 | 2012-07-04 | 山东轻工业学院 | Automatic timing device and timing method of capillary viscometer |
| CN104568053A (en) * | 2014-12-11 | 2015-04-29 | 中国核电工程有限公司 | Self-heating differential thermoresistor liquid level sensor and liquid level measurement method thereof |
| CN104568054A (en) * | 2014-12-11 | 2015-04-29 | 中国核电工程有限公司 | Liquid level sensor of heating type differential thermal resistor and liquid level measuring method thereof |
| CN104568054B (en) * | 2014-12-11 | 2018-11-20 | 中国核电工程有限公司 | A kind of heated type difference thermal resistance liquid level sensor and its method for measuring liquid level |
| CN104568053B (en) * | 2014-12-11 | 2018-11-20 | 中国核电工程有限公司 | A kind of self-heating difference thermal resistance liquid level sensor and its method for measuring liquid level |
| CN104608497A (en) * | 2015-01-20 | 2015-05-13 | 重庆工商大学 | Automatic ink supply system applied to printer |
| CN109892310A (en) * | 2019-04-04 | 2019-06-18 | 江阴职业技术学院 | A kind of adjustable crops field medicine liquid spray device |
| CN111637951A (en) * | 2020-05-27 | 2020-09-08 | 广州大学 | Photosensitive emulsion liquid level detection device and atomization method |
| CN111637951B (en) * | 2020-05-27 | 2022-03-22 | 广州大学 | Photosensitive emulsion liquid level detection device and atomization method |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090506 |