CN102778255A - High-precision liquid level, temperature, density multifunctional measuring system - Google Patents

High-precision liquid level, temperature, density multifunctional measuring system Download PDF

Info

Publication number
CN102778255A
CN102778255A CN2012102404852A CN201210240485A CN102778255A CN 102778255 A CN102778255 A CN 102778255A CN 2012102404852 A CN2012102404852 A CN 2012102404852A CN 201210240485 A CN201210240485 A CN 201210240485A CN 102778255 A CN102778255 A CN 102778255A
Authority
CN
China
Prior art keywords
liquid level
temperature
signal
main
sensor
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
Application number
CN2012102404852A
Other languages
Chinese (zh)
Inventor
赵玉龙
牛喆
郭方方
王建军
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xian Jiaotong University
Original Assignee
Xian Jiaotong University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Xian Jiaotong University filed Critical Xian Jiaotong University
Priority to CN2012102404852A priority Critical patent/CN102778255A/en
Publication of CN102778255A publication Critical patent/CN102778255A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)

Abstract

A high-precision liquid level, temperature, density multifunctional measuring system comprises a liquid level transducer, wherein the output signal of the liquid level transducer is transmitted to a signal processing and displaying circuit; a liquid level transducer shell is connected with a connection rod; the connection rod is connected with an anti-explosion junction box by an adapter; the signal processing and displaying circuit is fixed in the anti-explosion junction box; a contrast measurement sensor and a main liquid level measurement sensor, which are distributed up and down and are vertical to the liquid level, are packaged in the liquid level transducer shell; the back surface of the main liquid level measurement sensor is further provided with a temperature sensor; the signal processing and displaying circuit comprises two signal transducer units and is respectively connected with the main liquid level measurement sensor and the contrast measurement sensor; the two signal transducer units are connected with a main processor unit; the temperature sensor is connected with the main processor unit; and the main processor unit is connected with an LED (light emitting diode) display unit. The multifunctional measuring system is capable of synchronously measuring the liquid level, the density and the temperature of the liquid, and has the characteristics of high precision, high sensitivity and good linearity.

Description

A kind of high-precision liquid level, temperature, density multifunctional measuring system
Technical field
The invention belongs to the level gauging technical field, specially refer to a kind of high-precision liquid level, temperature, density multifunctional measuring system.
Background technology
Level gauging is the important detection index of enterprise automation, and the Detection & Controling to liquid levels such as jar, still, tower and interface have great significance to automated production in process of production.The kind of level gauging instrument is a lot of on the market; Differential pressure type level gauge is to use one of kind the most widely; Its measurement hydrostatic pressure of passing through obtains liquid level information; Have simple in structure, measure accurately and characteristics such as installation and maintenance are convenient, adaptable across fields such as chemical industry, metallurgy, power station, water conservancy, urban water supply and industrial waste waters.
But, in existing differential pressure levelmeter liquid level computing formula, employing be the fluid density of fixing, the density of general fluid to be measured receives temperature, pressure, the one-tenth factor affecting of grading bigger, the pressure uncertainty of build-up of pressure sensor measurement is also bigger.In the occasion that requires liquid level is carried out high-acruracy survey; For example diesel oil, gasoline small canister case, common differential pressure levelmeter is difficult to satisfy its requirement on the market, and existing liquid level gauge function singleness; Information such as energy measurement density of liquid, temperature can't comprehensively not fed back liquid information.
Summary of the invention
In order to overcome the shortcoming of above-mentioned prior art; The object of the present invention is to provide a kind of high-precision liquid level, temperature, density multifunctional measuring system; Can measure liquid level, density and the temperature of liquid simultaneously, have precision height, highly sensitive, characteristics that the linearity is good.
To achieve these goals, the technical scheme of the present invention's employing is following:
A kind of high-precision liquid level, temperature, density multifunctional measuring system comprise fluid level transmitter 1, and the output signal of fluid level transmitter 1 is sent into signal condition and display circuit 13;
Described fluid level transmitter 1; Its case top is connected with connecting link 2 bottoms; Connecting link 2 tops link to each other with anti-explosion terminal box 4 through adapter 3; Signal condition and display circuit 13 are fixed in the anti-explosion terminal box 4; Measurement of comparison sensor 8 and main BL 6 are packaged in fluid level transmitter 1 housing with the mode that distributes up and down perpendicular to liquid level, and the back side that is positioned at the main BL 6 of bottom also is provided with temperature sensor 5, and the signal output part of measurement of comparison sensor 8, main BL 6 and temperature sensor 5 is connected through air guide cable 7 and signal condition and display circuit 13;
Described signal condition and display circuit 13 comprise first signal transmission unit 9 and secondary signal transducing unit 10; The input end of first signal transmission unit 9 and secondary signal transducing unit 10 is connected with the signal output part of main BL 6 and measurement of comparison sensor 8 respectively; The output terminal of first signal transmission unit 9 and secondary signal transducing unit 10 is connected with first input end, second input end of main processor unit 11 respectively; The 3rd input end of the signal output part of temperature sensor 5 and main processor unit 11 is connected, and the output terminal of main processor unit 11 is connected with the input end of led display unit 12.
Described fluid level transmitter 1 uses the stainless steel encapsulating structure with connecting link 2.
Described measurement of comparison sensor 8 adopts high precision MEMS micro-pressure sensor with main BL 6.
Described temperature sensor 5 adopts numeric type temperature sensor DS18B20.
Described first signal transmission unit 9, secondary signal transducing unit 10 are based on the AD693 chip.
Described main processor unit 11 is based on the C8051F020 single-chip microcomputer.
The present invention measures simple and reliable, but high-acruracy survey liquid level, density and temperature; Fluid level transmitter 1 and connecting link 2 use stainless steel encapsulating structures are not only applicable to the measurement of light water, also are applicable to the level gauging of medium special occasions such as high temperature, thickness, corrosion.
Description of drawings
Fig. 1 is a theory diagram of the present invention.
Fig. 2 is a contour structures synoptic diagram of the present invention.
Fig. 3 is fluid level transmitter 1 structural representation.
Fig. 4-(a) is the circuit diagram of main processor unit 11, and Fig. 4-(b) is the circuit diagram of first signal transmission unit 9, and Fig. 4-(c) is the circuit diagram of secondary signal transducing unit 10.
Embodiment
Below in conjunction with accompanying drawing the present invention is done detailed description.
As shown in Figure 1, a kind of high-precision liquid level, temperature, density multifunctional measuring system comprise fluid level transmitter 1, and the output signal of fluid level transmitter 1 is sent into signal condition and display circuit 13;
As shown in Figures 2 and 3; Described fluid level transmitter 1; Its case top is connected with connecting link 2 bottoms; Connecting link 2 tops link to each other with anti-explosion terminal box 4 through adapter 3, and signal condition and display circuit 13 are connected and fixed in the anti-explosion terminal box 4 through bolt, and measurement of comparison sensor 8 and main BL 6 are packaged in fluid level transmitter 1 housing with the mode that distributes up and down perpendicular to liquid level; The back side that is positioned at the main BL 6 of bottom also is provided with temperature sensor 5, and the signal output part of measurement of comparison sensor 8, main BL 6 and temperature sensor 5 is connected through air guide cable 7 and signal condition and display circuit 13;
Described signal condition and display circuit 13 comprise first signal transmission unit 9 and secondary signal transducing unit 10; The input end of first signal transmission unit 9 and secondary signal transducing unit 10 is connected with the signal output part of main BL 6 and measurement of comparison sensor 8 respectively; The output terminal of first signal transmission unit 9 and secondary signal transducing unit 10 is connected with first input end, second input end of main processor unit 11 respectively; The 3rd input end of the signal output part of temperature sensor 5 and main processor unit 11 is connected, and the output terminal of main processor unit 11 is connected with the input end of led display unit 12.
Described fluid level transmitter 1 uses the stainless steel encapsulating structure with connecting link 2.
Described measurement of comparison sensor 8 adopts high precision MEMS micro-pressure sensor with main BL 6.
Described temperature sensor 5 adopts numeric type temperature sensor DS18B20.
Shown in Fig. 4-(a); Described main processor unit 11 has been selected the C8051F020 single-chip microcomputer for use; First signal transmission unit 9 is sent into Main Processor Unit 11 with the two-way voltage signal of secondary signal transducing unit 10 outputs and is obtained absolute difference and carry out A/D conversion, filtering and density conversion; Obtain density information; One road voltage signal of main simultaneously BL 8 outputs carries out the A/D conversion of single-ended input form in primary processor 11, through further handling the liquid level information that obtains, numeric type temperature sensor DS18B20 is output as digital signal and directly sends into single-chip microcomputer and convert and obtain temperature information.Integrated 12 8 passage ADC on the C8051F020 single-chip microcomputer sheet do not need the outer analog to digital conversion chip of sheet, have simplified circuit structure, have higher precision.
Like Fig. 4-(b); Shown in the 4-(c); Described first signal transmission unit 9, secondary signal transducing unit 10 have identical circuit structure; All adopted the AD693 chip, main BL 6 and measurement of comparison sensor 8 output signals are sent into first signal transmission unit 9 respectively and are carried out processing such as filtering, amplification with secondary signal transducing unit 10 and obtain two-way 1-5V standard signal.
Principle of work of the present invention is:
During use; The lower end of fluid level transmitter 1 is fixed under the liquid level perpendicular to liquid level; The lower end of fluid level transmitter 1 is fixed on the liquid level; The main BL 6 that is positioned at fluid level transmitter 1 lower end leads directly to atmosphere with the measurement of comparison sensor 8 that is positioned at fluid level transmitter 1 upper end through air guide cable 7 back pressures, and main BL 6 is met the pressure survey that liquid level carries out liquid with measurement of comparison sensor 8; Temperature sensor 5 carries out temperature survey.
Density measure principle: Δ P=P 6-P 8=ρ .g.L; Wherein: P 6, P 8Be respectively the pressure output value of main BL 6 and measurement of comparison sensor 8; The difference in height of L-master's BL 6 and measurement of comparison sensor 8; ρ-measured medium density; The acceleration of gravity of the tested locality of g-.The difference in height of main BL 6 and measurement of comparison sensor 8 is a definite value, and the differential pressure Δ P that records is directly proportional with density of liquid ρ, has so just become the problem of measuring differential pressure to the problem of measuring fluid density.
The level gauging principle: when liquid level gauge was put in the fluid to be measured a certain degree of depth, it was P that main BL 6 is met the pressure that liquid level receives 6=ρ .g.H+Po; In the formula: P-master's BL 6 is met the liquid level pressure; ρ-fluid to be measured density measures with measurement of comparison sensor 8 through main BL 6; The g-local gravitational acceleration; Atmospheric pressure on the Po-liquid level; The H-transmitter drops into the degree of depth of liquid.Simultaneously, the negative pressure cavity that the atmospheric pressure Po on the liquid level is caused main BL 6 is met the Po of liquid level with offset sensor, and making main BL 6 record pressure is Ρ 6=ρ .g.H.Therefore, main BL 6 records pressure and is directly proportional with the height H of liquid, has so just become the problem of the height of measuring liquid the problem of gaging pressure.
In measuring process, processing such as main BL 6 and the two paths of signals of measurement of comparison sensor 8 outputs send into respectively that first signal transmission unit 9 amplifies with secondary signal transducing unit 10, filtering and V/I conversion become the normal voltage signal of 1-5V.The two-way voltage signal is sent into Main Processor Unit 11 and is obtained absolute difference and carry out A/D conversion, filtering and density conversion; Obtain density information; One road voltage signal of main simultaneously BL 8 outputs carries out the A/D conversion of single-ended input form in primary processor 11, through further handling the liquid level information that obtains.Numeric type temperature sensor DS18B20 is output as digital signal and directly sends into single-chip microcomputer and convert and obtain temperature information.At last single-chip microcomputer being handled data such as gained density, liquid level and temperature sends into led display unit 12 and shows.
Main liquid level sensor 6 causes the measuring error under the varying environment temperature with measurement of comparison sensor 8 owing to " temperature is floated "; In main liquid level sensor 6 back mounting temperature sensors 5 measured temperature values; And, can effectively improve the measuring accuracy of density and liquid level according to the influence that measured temperature value compensation temperature causes measurement result.
The piezoresistance coefficient of pressure resistance type element has bigger temperature coefficient, causes the sensitivity of MEMS micro-pressure sensor and zero point drift bigger, and the present invention has adopted the temperature compensation algorithm based on least square method, improves output result's the linearity.The present invention has adopted median average filter method can eliminate because the caused sampled value deviation of impulse disturbances, improves the precision of measuring, and software filtering has than hardware filtering effect better simultaneously, and has simplified circuit.

Claims (6)

1. a high-precision liquid level, temperature, density multifunctional measuring system comprise fluid level transmitter (1), and it is characterized in that: the output signal of fluid level transmitter (1) is sent into signal condition and display circuit (13);
Described fluid level transmitter (1); Its case top is connected with connecting link (2) bottom; Connecting link (2) top links to each other with anti-explosion terminal box (4) through adapter (3); Signal condition and display circuit (13) are fixed in the anti-explosion terminal box (4); Measurement of comparison sensor (8) and main BL (6) are packaged in fluid level transmitter (1) housing with the mode that distributes up and down perpendicular to liquid level; The back side that is positioned at the main BL (6) of bottom also is provided with temperature sensor (5), and the signal output part of measurement of comparison sensor (8), main BL (6) and temperature sensor (5) is connected through air guide cable (7) and signal condition and display circuit (13);
Described signal condition and display circuit (13) comprise first signal transmission unit (9) and secondary signal transducing unit (10); The input end of first signal transmission unit (9) and secondary signal transducing unit (10) is connected with the signal output part of main BL (6) with measurement of comparison sensor (8) respectively; The output terminal of first signal transmission unit (9) and secondary signal transducing unit (10) is connected with first input end, second input end of main processor unit (11) respectively; The signal output part of temperature sensor (5) is connected with the 3rd input end of main processor unit (11), and the output terminal of main processor unit (11) is connected with the input end of led display unit (12).
2. a kind of high-precision liquid level according to claim 1, temperature, density multifunctional measuring system is characterized in that: described fluid level transmitter (1) and connecting link (2) use the stainless steel encapsulating structure.
3. a kind of high-precision liquid level according to claim 1, temperature, density multifunctional measuring system is characterized in that: described measurement of comparison sensor (8) and main BL (6) adopt high precision MEMS micro-pressure sensor.
4. a kind of high-precision liquid level according to claim 1, temperature, density multifunctional measuring system is characterized in that: described temperature sensor (5) adopts numeric type temperature sensor DS18B20.
5. a kind of high-precision liquid level according to claim 1, temperature, density multifunctional measuring system is characterized in that: described first signal transmission unit (9), secondary signal transducing unit (10) are based on the AD693 chip.
6. a kind of high-precision liquid level according to claim 1, temperature, density multifunctional measuring system is characterized in that: described main processor unit (11) is based on the C8051F020 single-chip microcomputer.
CN2012102404852A 2012-07-12 2012-07-12 High-precision liquid level, temperature, density multifunctional measuring system Pending CN102778255A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2012102404852A CN102778255A (en) 2012-07-12 2012-07-12 High-precision liquid level, temperature, density multifunctional measuring system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2012102404852A CN102778255A (en) 2012-07-12 2012-07-12 High-precision liquid level, temperature, density multifunctional measuring system

Publications (1)

Publication Number Publication Date
CN102778255A true CN102778255A (en) 2012-11-14

Family

ID=47123250

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2012102404852A Pending CN102778255A (en) 2012-07-12 2012-07-12 High-precision liquid level, temperature, density multifunctional measuring system

Country Status (1)

Country Link
CN (1) CN102778255A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104132674A (en) * 2014-07-31 2014-11-05 西安交通大学 Multi-signal output intelligent pressure transmitter
CN105067038A (en) * 2015-08-10 2015-11-18 上海峥岚实业有限公司 Multi-parameter density/ liquid level instrument and manufacture method thereof
CN105371891A (en) * 2015-09-25 2016-03-02 河海大学 Multifunctional integrated data collection system for indoor oscillation test platform
CN107702749A (en) * 2017-10-16 2018-02-16 中国核动力研究设计院 A kind of liquid waste evaporator multiparameter measuring device and measuring method
CN109341669A (en) * 2018-10-31 2019-02-15 广东小天才科技有限公司 Water-depth measurement method and device
CN109827636A (en) * 2019-03-14 2019-05-31 国投新疆罗布泊钾盐有限责任公司 Digital liquid level measuring instrument
CN109900308A (en) * 2019-02-19 2019-06-18 南京南瑞水利水电科技有限公司 A kind of sensor it is artificial than examining system and its method
CN110410666A (en) * 2019-07-08 2019-11-05 环宇智谷(北京)科技有限公司 A kind of Internet of things system based on NB-IOT intelligent radio transmitter
CN114609344A (en) * 2022-03-29 2022-06-10 南京高华科技股份有限公司 Concentration measuring device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1489014A (en) * 2003-08-08 2004-04-14 河南安彩高科股份有限公司 Glass bulb slurry level-concentration control system
CN102322897A (en) * 2011-08-27 2012-01-18 蚌埠迅科自控有限公司 Intelligent slurry density and liquid level integrative analysis instrument and analysis method
CN102359923A (en) * 2011-06-20 2012-02-22 东莞广州中医药大学中医药数理工程研究院 Device for measuring density and liquid level of liquid medicine on line in process of producing Chinese medicines

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1489014A (en) * 2003-08-08 2004-04-14 河南安彩高科股份有限公司 Glass bulb slurry level-concentration control system
CN102359923A (en) * 2011-06-20 2012-02-22 东莞广州中医药大学中医药数理工程研究院 Device for measuring density and liquid level of liquid medicine on line in process of producing Chinese medicines
CN102322897A (en) * 2011-08-27 2012-01-18 蚌埠迅科自控有限公司 Intelligent slurry density and liquid level integrative analysis instrument and analysis method

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104132674A (en) * 2014-07-31 2014-11-05 西安交通大学 Multi-signal output intelligent pressure transmitter
CN105067038A (en) * 2015-08-10 2015-11-18 上海峥岚实业有限公司 Multi-parameter density/ liquid level instrument and manufacture method thereof
CN105371891A (en) * 2015-09-25 2016-03-02 河海大学 Multifunctional integrated data collection system for indoor oscillation test platform
CN107702749A (en) * 2017-10-16 2018-02-16 中国核动力研究设计院 A kind of liquid waste evaporator multiparameter measuring device and measuring method
CN109341669A (en) * 2018-10-31 2019-02-15 广东小天才科技有限公司 Water-depth measurement method and device
CN109900308A (en) * 2019-02-19 2019-06-18 南京南瑞水利水电科技有限公司 A kind of sensor it is artificial than examining system and its method
CN109827636A (en) * 2019-03-14 2019-05-31 国投新疆罗布泊钾盐有限责任公司 Digital liquid level measuring instrument
CN110410666A (en) * 2019-07-08 2019-11-05 环宇智谷(北京)科技有限公司 A kind of Internet of things system based on NB-IOT intelligent radio transmitter
CN114609344A (en) * 2022-03-29 2022-06-10 南京高华科技股份有限公司 Concentration measuring device

Similar Documents

Publication Publication Date Title
CN102778255A (en) High-precision liquid level, temperature, density multifunctional measuring system
CN102494670A (en) Method for monitoring foundation settlement by using static water level gauge and static water level gauges used in method
CN102146648B (en) High-speed railway structure settlement monitoring device and monitoring method
CN202351148U (en) High-precision throw-in type liquid density and level sensor
CN203719811U (en) Weak voltage signal detection device of micro-voltage sensor
CN104976988A (en) Tunnel large-elevation-difference settlement measuring system
CN203310718U (en) Device for measuring density and liquid level height of engine fuel oil
CN101839711A (en) Portable digitalized high-precision tilt angle measuring instrument and measuring method
CN107091667A (en) The liquid level detection system that a kind of use temperature sensor is realized
CN100392362C (en) Liquid level transmitter for sealed oil tank
CN206177288U (en) A testing arrangement for component slant angle measuring
CN113899344B (en) High-precision settlement monitoring system and method for long tunnel considering temperature effect
CN201688837U (en) Portable digital high-accuracy dipmeter
CN106895886B (en) High-sensitivity gas flow measuring device and method based on giant piezoresistive sensor
CN202372170U (en) Static level instrument
CN210666065U (en) Calibration device of seismic intensity instrument
CN205228583U (en) Accurate liquid level measurement probe
CN216954495U (en) Low-temperature drift detection system of high-speed railway foundation settlement monitoring hydrostatic level
CN207231472U (en) Fixed capacitive grating encoder inclination measurement device, inclinometer, deviation survey equipment and inclination measurement system
CN102279029A (en) Self-calibrating putting-into-type pressure liquid level meter and measuring method thereof
CN206648643U (en) Based on piezoresistive transducer DCM BD settlement monitoring level meters
CN201060079Y (en) Intelligent differential pressure cell
CN113654518A (en) Low-temperature drift detection system of high-speed railway foundation settlement monitoring hydrostatic level
CN204924517U (en) Portable electronic dynamometer
CN204064232U (en) A kind of deflection of bridge span network monitoring system

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C12 Rejection of a patent application after its publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20121114