CN1673731A - Apparatus and method for measuring conducting fluid density - Google Patents
Apparatus and method for measuring conducting fluid density Download PDFInfo
- Publication number
- CN1673731A CN1673731A CN 200510069943 CN200510069943A CN1673731A CN 1673731 A CN1673731 A CN 1673731A CN 200510069943 CN200510069943 CN 200510069943 CN 200510069943 A CN200510069943 A CN 200510069943A CN 1673731 A CN1673731 A CN 1673731A
- Authority
- CN
- China
- Prior art keywords
- circuit
- conducting fluid
- electrode
- fluid density
- control circuit
- 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.)
- Granted
Links
Images
Abstract
The conducting fluid measurement equipment includes probe and control circuit. The probe includes one insulating pipe and two electrodes, the electrodes are inserted transversely into the insulating pipe in the place near one end and connected to the control circuit, and the insulating pipe has the other end connected to reference pressure, which is regulated to make the flow speed of the solution passing by the electrodes similar to local flow speed. The control circuit includes AC source, electrode controlling circuit, rectifier circuit, integrating circuit and signal locking circuit, and the signal the electrodes acquire is processed in the rectifier circuit, the integrating circuit and the signal locking circuit before being fed to computer for data processing. The present invention can measure the density distribution and instantaneous pulse information of conducting fluid and may be used in turbulent flow research of conducting fluid.
Description
Technical field
The present invention relates to a kind of measurement mechanism and measuring method of conducting fluid density.
Background technology
The density of fluid goes to determine by certain status method usually in the flow field, but, for conductive fluid, because its density generally changes continuously with dielectric concentration, and dielectric concentration and conductivity are one to one, therefore can remove to measure conducting fluid density by the measurement of conductivity, but also not have relevant report at present.
Conductivity generally can adopt traditional bridge method to measure, but because electric bridge is regulated very time-consumingly, this method also is not suitable in the vertiginous flow field of conductivity.Johnson and Enke (1 970) have invented a kind of alternating impulse voltage technology [Johnson, D.E., and Enke, C.G., " Bipolar Pulse Technique for Fast Conductance Measurements, " AnalyticChemistry, Vol.42, No.3,1970.], can be used for measuring rapidly the conductivity of uniform dielectric solution.Daum and Nelson (1973) have further developed out alternating impulse electric current technology [Daum on this basis, P.H.and Nelson, D.F., " Bipolar Current Method forDetermination of Solution Resistance; " Analytic Chemistry, Vol.45, No.3,1973.], be mainly used to measure fast the conductivity of high concentration uniform dielectric solution.Two kinds of methods have adopted the way of passing through equal strength alternating impulse voltage or electric current in dielectric solution respectively, pass through analytical proof, resistance between the electrode is proportional to electrode response voltage signal intensity of integration again after rectification, therefore can be used for measuring the conductivity of solution.Because the pulse signal width that is adopted is very narrow, generally is 10 microsecond magnitudes, said method can record the conductivity of uniform fluid fast.But, for the flow field of non-homogeneous conductivity, because the resistance between the electrode is an integration amount, the signal that alternating impulse electric current technology provides will comprise the influence of surrounding fluid concentration, and influence is very big, therefore can't carry out one-point measurement to the density of Non-uniform Currents.This problem is even more serious in vertiginous flow field, thereby in fact can not actually use.
Summary of the invention
At the defective that prior art exists, the object of the present invention is to provide a kind of measurement mechanism of conducting fluid density, this device can carry out one-point measurement to conductivity of fluid in the nonstationary flow field.
Further, the object of the present invention is to provide a kind of measuring method that adopts the conducting fluid density of said apparatus.
For realizing purpose of the present invention, the measurement mechanism of a kind of conducting fluid density of the present invention comprises: probe and control circuit, described probe comprises an insulation tube and two electrodes, the suitable distance of described insulation tube one end of described two electrode distances is laterally inserted this insulation tube side by side, and link to each other with described control circuit, the other end of described insulation tube links to each other with reference pressure, by regulating reference pressure so that suitable with local flowing velocity through the flow of solution speed of electrode; Described control circuit comprises alternate current-changing source, electrode control circuit, rectification circuit, integrating circuit and signal lock circuit, alternate current-changing source charges to described electrode, the signal that electrode control circuit is gathered described electrode is imported computing machine at last and is carried out data processing successively through rectification circuit, integrating circuit and signal lock circuit.
Further, also comprise a buffer circuit of being made up of optocoupler components, the electric signal of described signal lock circuit output is input in the computing machine through behind this buffer circuit again.
Further, the model of described optocoupler components is 4N25.
Further, described electrode is a platinum filament.
The measuring method of a kind of conducting fluid density of the present invention is: adopt described conducting fluid density measurement mechanism earlier solution to be measured to be carried out data scaling, obtain the corresponding change curve of output voltage and solution density, adopt described conducting fluid density measurement mechanism in actual measurement, data and the nominal data that obtains to be compared then, thereby obtain Density Distribution.
The present invention can be rapidly and is measured the Density Distribution and the instantaneous pulsation information thereof of conductive fluid exactly, comprises fluctuation intensity and frequency, can be applied to the turbulent flow research of conductive fluid.
Description of drawings
Fig. 1 is the measurement mechanism structural representation of conducting fluid density of the present invention;
Fig. 2 is a probe structure synoptic diagram of the present invention;
Fig. 3 is control circuit figure of the present invention and control signal;
Fig. 4 is that the present invention is to NaCl standardizing of solution curve;
NaCl density is along the scanning curve of water hole short transverse in the water hole that Fig. 5 surveys for the present invention.
Embodiment
As shown in Figure 1, the measurement mechanism of conducting fluid density of the present invention comprises: probe, control circuit, probe connect control circuit successively, be buffer circuit and the computing machine that the optocoupler components of 4N25 is formed by model.In order to isolate the influence of surrounding fluid to measuring effectively, the present invention has designed special sampling probe, as shown in Figure 2.Probe employing external diameter is that insulation (plastic and glass) tubule 2 of 1.6mm is made, and head is contracted to about 1.0mm by the stretching external diameter, its objective is for the ease of fixing, and internal diameter is about 0.5mm.Electrode 1 adopts two platinum filaments that diameter is 0.13mm, laterally inserted head tubule, and spacing is about 12.7mm, and wherein the distance of first platinum filament and end of probe is about 3.2mm.Electrode 1 is drawn lead 3 and is linked to each other with platinum filament by welding, and the blended rubber hydropexis is at detecting probe surface.For fear of short circuit, all leads and interface all adopt the silicone rubber seal insulation.Probe links to each other with reference pressure, the sampling electrode 1 of flowing through.Reference pressure is adjustable continuously, so that flowing velocity in the sampling pipe and the speed that flows with the locality are suitable, thereby can carry out continuous sampling to the instantaneous density of conductive fluid.Because the fluid discharge currents after the sampling outside the venue, electrode 1 electric current is limited between two electrodes 1, has isolated the influence of surrounding fluid to resistance between the electrode 1 effectively, thereby can carry out one-point measurement to conductivity of fluid in the nonstationary flow field.
The control circuit of probe and corresponding switching signal G, H, J and K are as shown in Figure 3.It is similar that ultimate principle and Daum and Nelson design, but owing to adopt computing machine to generate switching signal greatly simplification with carrying out data acquisition automatically.Among Fig. 2, control circuit is made up of alternate current-changing source 4, electrode control circuit 5, rectification circuit 6, integrating circuit 7 and signal lock circuit 8 five parts successively, 4 pairs of electrodes 1 of alternate current-changing source charge, the signal that electrode control circuit 5 is gathered electrode 1 carries out data processing by buffer circuit input computing machine at last successively through rectification circuit 6, integrating circuit 7 and signal lock circuit 8.The negative edge of signal J triggers sampling process, and the negative edge of signal K locking output signal and trigger the data acquisition system (DAS) of computing machine.Charging process to electrode 1 is divided into the two equal stages, by signal G and H control, corresponds respectively to by forward and inverse current.During actual measurement, signal J, the pulse width of K is set to 20 microseconds, and the pulse width of G and H is its half, i.e. 10 microseconds.The corresponding exchange current source signal of the output signal of node A, the corresponding probe electrode response of B, C represents the signal after the rectification, as shown in Figure 2.In order to prevent that electrode 1 from producing bypass by conductive fluid or computer circuitry ground connection, cause very big measuring error, control circuit adopts battery-operated, and isolates by a buffer circuit of being made up of optocoupler components (4N25) before signal enters computing machine.
Fig. 4 has provided the density probe system at given concentration NaCl standardizing of solution data.By fitting of a polynomial, can obtain a pairing solution density curve of different output voltages.As we know from the figure, the output voltage of system can be mapped well with the density of solution, and when low-density, there is very high resolution (unit intensity changes the change in voltage that produces) in system, but, the response of system is non-linear, and along with the increase of density, the resolution of system will reduce.This problem can solve by the way of subregion, also, between different density regions, adopts different pulse current intensity to remove to drive probe electrode.During concrete the experiment, the density of fluid can obtain by output voltage and calibration curve Fig. 3 of system.
Total system is tested in the water hole.Water tunnel test section xsect is 12.7mm * 203.2mm, the about 0.7m/s of flowing velocity.Be the NaCl solution of 4M at 101.6mm place, measurement point upstream injection concentration in the flow field, the injection flow is about 2.2% of main flow flow.Probe adopts step motor drive, moves 100 times in short transverse per second kind, and 0.025mm rises at every turn.Fig. 5 has provided a Density Distribution example that measures.Measure curve and not only provided being evenly distributed of density, also provided the pulsation information of density.Can estimate that from figure density is in the y direction, promptly on the water tunnel test section height, the characteristic length of pulsation is about 0.01h, and about 0.13mm is equivalent to probe and moves about 5 steps, and 0.05 second at interval, so the ripple frequency of fluid density is about 20hz.Consider the about 0.7m/s of flowing velocity, flow performance length be about the test section height half be 6.4mm, the mobile characteristic time is about 20hz.In addition for probe itself, because two electrode separations are about 12.7mm, flowing velocity u and main flow in the sampling conduit are suitable, about 0.5m/s, and then the probe highest frequency that can detect is about 40hz, can satisfy the measurement requirement in this example fully.
Spacing between two electrodes can suitably be regulated according to actual conditions.At first, for Non-Uniform Flow, electrode separation must be enough short, generally should be less than the characteristic length that is flowing on the sampling direction, to guarantee enough spatial resolutions.And owing to adopted the sample rate suitable with flowing velocity, when electrode distance during less than flow performance length, the sampling response frequency of electrode will be higher than mobile characteristic frequency; Secondly, the necessary long enough of electrode separation so that the resistance of fluid is enough big between electrode, can come out by alternating impulse electric current technology for detection.For very little spacing, can increase resistance value by the bore that dwindles sampling pipe.The present invention is based on the mentioned above principle designed probe, through experimental verification, can be rapidly and measure the Density Distribution and the instantaneous pulsation information thereof of conductive fluid exactly, comprise fluctuation intensity and frequency, can be applied to the turbulent flow research of conductive fluid.
Claims (5)
1, a kind of measurement mechanism of conducting fluid density, it is characterized in that, comprise: probe and control circuit, described probe comprises an insulation tube and two electrodes, the suitable distance of described insulation tube one end of described two electrode distances is laterally inserted this insulation tube side by side, and link to each other with described control circuit, the other end of described insulation tube links to each other with reference pressure, by regulating reference pressure so that suitable with local flowing velocity through the flow of solution speed of electrode; Described control circuit comprises alternate current-changing source, electrode control circuit, rectification circuit, integrating circuit and signal lock circuit, alternate current-changing source charges to described electrode, the signal that electrode control circuit is gathered described electrode is imported computing machine at last and is carried out data processing successively through rectification circuit, integrating circuit and signal lock circuit.
2, the measurement mechanism of conducting fluid density according to claim 1 is characterized in that, also comprises a buffer circuit of being made up of optocoupler components, and the electric signal of described signal lock circuit output is input in the computing machine through behind this buffer circuit again.
3, the measurement mechanism of conducting fluid density according to claim 2 is characterized in that, the model of described optocoupler components is 4N25.
4, the measurement mechanism of conducting fluid density according to claim 3 is characterized in that, described electrode is a platinum filament.
5, a kind of employing is as the measuring method of the conducting fluid density of the measurement mechanism of the arbitrary conducting fluid density of claim 1 to 4, it is characterized in that, adopt described conducting fluid density measurement mechanism earlier solution to be measured to be carried out data scaling, obtain the corresponding change curve of output voltage and solution density, adopt described conducting fluid density measurement mechanism in actual measurement, data and the nominal data that obtains to be compared then, thereby obtain Density Distribution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100699430A CN100405047C (en) | 2005-05-11 | 2005-05-11 | Apparatus and method for measuring conducting fluid density |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100699430A CN100405047C (en) | 2005-05-11 | 2005-05-11 | Apparatus and method for measuring conducting fluid density |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1673731A true CN1673731A (en) | 2005-09-28 |
| CN100405047C CN100405047C (en) | 2008-07-23 |
Family
ID=35046405
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100699430A Expired - Fee Related CN100405047C (en) | 2005-05-11 | 2005-05-11 | Apparatus and method for measuring conducting fluid density |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100405047C (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101514958B (en) * | 2008-02-19 | 2011-04-20 | 瑞鼎科技股份有限公司 | Fluid measuring device |
| CN101398400B (en) * | 2007-09-28 | 2011-11-09 | 中国核动力研究设计院 | Conductivity electrode flowing and mixing measuring systems |
| CN101711351B (en) * | 2007-06-30 | 2012-04-11 | 恩德斯+豪斯流量技术股份有限公司 | Measuring system for a medium flowing in a process line |
| CN101796386B (en) * | 2007-06-30 | 2012-05-16 | 恩德斯+豪斯流量技术股份有限公司 | Measuring system for a medium flowing in a process line |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3769831A (en) * | 1971-10-13 | 1973-11-06 | Itt | Densitometer |
| US3878374A (en) * | 1973-12-10 | 1975-04-15 | Itt | Densitometer |
| US4751466A (en) * | 1987-01-20 | 1988-06-14 | Ford Motor Company | Instrument for on-line measurement of the absolute electrical conductivity of a liquid |
| CN2072686U (en) * | 1990-06-06 | 1991-03-06 | 机械电子工业部第四十九研究所 | Small-diameter high-temp. high-pressure differential densimeter |
-
2005
- 2005-05-11 CN CNB2005100699430A patent/CN100405047C/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101711351B (en) * | 2007-06-30 | 2012-04-11 | 恩德斯+豪斯流量技术股份有限公司 | Measuring system for a medium flowing in a process line |
| CN101796386B (en) * | 2007-06-30 | 2012-05-16 | 恩德斯+豪斯流量技术股份有限公司 | Measuring system for a medium flowing in a process line |
| CN101398400B (en) * | 2007-09-28 | 2011-11-09 | 中国核动力研究设计院 | Conductivity electrode flowing and mixing measuring systems |
| CN101514958B (en) * | 2008-02-19 | 2011-04-20 | 瑞鼎科技股份有限公司 | Fluid measuring device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100405047C (en) | 2008-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101057125A (en) | Method for testing a magnetic inductive flow meter | |
| CN1879015A (en) | System and method for monitoring defects in structures | |
| CN101413911A (en) | Method and device for measuring two-phase flow parameter based on double-end capacitance probe | |
| CN104678186B (en) | The measuring system of capacitive touch screen sensor | |
| CN102175130B (en) | Real-time measuring device and measuring method for thickness of gas-containing liquid film in interface fluctuation | |
| CN100405047C (en) | Apparatus and method for measuring conducting fluid density | |
| CN103513111A (en) | System and method for testing electric conductivity of metal wire | |
| CN202948069U (en) | Measuring device for solution conductivity | |
| CN107728036A (en) | Hall effect tester and method of testing | |
| CN100434906C (en) | Electrical conductance probe measurement system for real-time measurement of phase content and phase interface in multiple-phase pipe flow system | |
| CN1721862A (en) | Method and equipment for recording lightning stroke current intensity and occurrence time | |
| CN104678134B (en) | AC constant-current source, internal resistance of cell detection means and cell tester | |
| CN207964570U (en) | A kind of adjustable grain count device of accuracy of detection | |
| CN1170125C (en) | Intelligent frequency conversion, current transform type excitation method and electromagnetic flow meter | |
| DE4042257A1 (en) | Electrically conducting liquids level measurement - using discrete sensor positions, e.g. inform of metal surfaces along vertical bar | |
| CN104067113B (en) | The conductivity type contact test system of low conductivity | |
| CN1621782A (en) | Method of operating a measuring apparatus | |
| CN1797014A (en) | Detection method for testing current in resistance property of lightning arrester | |
| CN204514975U (en) | AC constant-current source, internal resistance of cell pick-up unit and cell tester | |
| KR101681179B1 (en) | Potentiometric Cytometer Microchip for Microdispersion Analysis and Quantification | |
| CN105115885B (en) | A kind of portable ground net corrosion condition monitoring system and monitoring method | |
| CN109048023A (en) | A kind of electric motor of automobile stator lead welding monitoring system and its monitoring method | |
| CN208672715U (en) | A kind of Estimate of Resistance for DC Low Resistance monitoring system that multichannel is tested simultaneously | |
| CN210486978U (en) | Oil gas field flow metering system | |
| CN204287125U (en) | A kind of transformer oil chromatographic on-line monitoring equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| 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: 20080723 Termination date: 20170511 |