WO2010142282A1 - Procédé et ensemble pour déterminer des paramètres d'un liquide - Google Patents

Procédé et ensemble pour déterminer des paramètres d'un liquide Download PDF

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Publication number
WO2010142282A1
WO2010142282A1 PCT/DE2010/000659 DE2010000659W WO2010142282A1 WO 2010142282 A1 WO2010142282 A1 WO 2010142282A1 DE 2010000659 W DE2010000659 W DE 2010000659W WO 2010142282 A1 WO2010142282 A1 WO 2010142282A1
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measuring
voltage
measuring cell
determined
electrodes
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German (de)
English (en)
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Udo Braatz
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Priority to DE112010002357T priority Critical patent/DE112010002357A5/de
Priority to EP10734436A priority patent/EP2457084A1/fr
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Anticipated expiration legal-status Critical
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
    • G01N27/06—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a liquid

Definitions

  • the invention relates to a method and an arrangement for determining the mean mobility ⁇ and the mean concentration n of ions and the pH of a liquid.
  • the determination of the mobility of a single type of ion is possible according to the prior art only with great technical effort.
  • the migration speed is determined only by a kind of ions having a certain color.
  • one "Textbook of Physical Chemistry” by Gerd Wedler was found in a Mn0 4 ⁇ + ion migration speed of 5 * 10 "4 Cms" (WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 5th edition; for example, page 207 , IM) Because the ions are generally colorless, this method is not relevant in practice.
  • the Cohen electrolysis cell for determining the Hittorf see transfer numbers (/ 1 /, page 207 - 211) allows under certain conditions, for example. the separate determination of ⁇ positive and negative charged ions using an optical method for detecting small volume differences. This method has a scientific rather than an applicative meaning.
  • Quantum sizes can not be determined with optical methods because of the uncertainty principle.
  • the dimensional analysis also called volumetry, offers.
  • a solution of known concentration to be examined is added to a solution of unknown concentration, the volumes of these solutions being known. The addition takes place until a chemical reaction occurs.
  • the concentration of the investigated solution (titrant) can be determined from the applied volume of the solution. This is greatly simplified, the essence of the large and diverse field of titration (company brochure: "Practical titration", Metrohm AG in Herisau / Switzerland, -2005-01, IZI).
  • the known pH measurement technique is based on the application of the Nernst equation (JM, page 450). It simply expresses the temperature-dependent relationship between the measured voltage (equal to the potential difference) of the pH electrode and the pH value of a fluid (Company brochure: "Metrosensor Electrodes", Metrohm AG in Herisau / Switzerland, -2006-01, ISI ).
  • the commercial pH meter systems usually consist of the combined glass or metal electrode, i. from a pH and a reference electrode with an additional integrated temperature sensor. At the end of a measurement, the meter displays the pH and temperature. Most measuring devices also allow the display of the corresponding measuring voltage in mV.
  • EP 0 929 804 B1 / 6 / discloses an analysis cell which consists of a pair of electrodes between which there is a porous membrane.
  • the redox system is a quinone-hydroquinone system.
  • this analysis cell has a special structure, which differs from the known glass electrode systems.
  • EP 0 456 154 B1 / 7 / proposes an electrochemical measuring device for determining the equivalence concentration of a sample solution, in which the potential differences to specific equivalence concentrations are determined with the aid of an electrode device.
  • EP 1 365232 B1 / 8 / describes a "solid-state pH sensor" with which the potential can be determined with a working electrode and a reference electrode, each coated with different materials. This invention leaves the concept of the commercial glass electrode system.
  • a disadvantage of the prior art is also that for liquids with only a small proportion of water, i. about ⁇ 5%, no pH values can be determined.
  • This relates in particular to high-resistance liquids, e.g. Biodiesel, lubricating oils or waste oils.
  • the commercial measuring systems in particular pH probes, are known to be very sensitive to contamination of the liquid, high mechanical loads or spontaneous temperature changes or high temperatures. Also, the installation and maintenance of said pH probes for process measurement are problematic and technically complex.
  • the invention is therefore based on the object to provide a method and a widely usable arrangement for the determination of parameters of liquids, with which both the average mobility ⁇ and the average concentration n of ions and the pH can be determined. And from thin and viscous as well as polluted and almost anhydrous liquids.
  • the object is achieved by a method for the determination of liquid parameters, the average mobility ⁇ and the average concentration n of ions and the pH, in which at a constant temperature T c and a constant total voltage U c , the zero or different from Can be zero, and which is applied to a measuring chamber M k with a measuring cell M z with the liquid to be tested S x and at least two parallel spaced d arranged electrodes E 1 and E 2 with the surfaces A 1 and A 2 , initially a measuring voltage U m detected at a measuring resistor R m and in a defined cycle time t, a measuring current I n ,, after
  • n d ⁇ z ⁇ / (e ⁇ ⁇ dl ) Eq. 6
  • the measuring current l m by means of a connected in series with the measuring cell M z digital ammeter (DA), with a digital current-voltage converter or with the external measuring resistor R m and connected in parallel with digital voltmeter (DV) or instead, with Help of an oscilloscope or recorder or voltage converter.
  • a further embodiment provides that at a constant total voltage U c different from zero this periodically, alternately, ie as + U c and -U 0 for the same or different duration .DELTA.t with or without short circuit of the measuring cell M z during a dead time or dead time created and provided by a Polwender.
  • an embodiment provides that the total voltage U 0 can be applied as a constant alternating voltage with a constant or variable frequency.
  • temporally variable voltages or voltage pulses with the amplitude ⁇ U C can be applied.
  • the intervals ⁇ t of the cycle times t, constant or freely selectable values are used as intervals ⁇ t.
  • the object is further achieved by an arrangement for determining fluid parameters by the method according to the aforementioned features, consisting of
  • a measuring chamber M k for receiving the liquid to be measured S x , with a arranged in the measuring chamber M k measuring cell M z with at least two equally spaced d arranged electrodes E 1 and E 2 with the conductive surfaces A 1 and A 2 and a Temperature sensor T s ,
  • a particularly advantageous embodiment of the arrangement according to the invention provides that the means for measuring the current l m is a sensitive digital ammeter (similar to a ballistic galvanometer), a measuring resistor R m, a digital voltmeter DV connected to determine the voltage drop across the measuring resistor R m , an oscilloscope, a voltage current transformer or a recorder.
  • all but the mutually positioned conductive electrode surfaces A 1 and A 2 all other surfaces of the electrodes E 1 and E 2 are formed isolated.
  • the measuring chamber M k can be heated or cooled directly or indirectly.
  • the electronic module is equipped with software for calculating, storing and displaying the liquid parameters.
  • R m has a value of up to 10 9 ⁇ .
  • the measuring chamber M k or the entire arrangement are shielded against electromagnetic influences.
  • the arrangement with the aforementioned technical features for the determination, control and monitoring of the parameters of liquids preferably in combustion or electric motors and / or in technological processes and / or hydraulic systems and / or in medical technology and / or in wind turbines and / or used in supply lines and / or in titration technology and / or in laboratory and field measurement technology.
  • the arrangement is particularly preferably used for monitoring and monitoring the parameters of liquids as immersion measuring cell, immersion probe, measuring cell with a defined volume, as a flow measuring cell, as a flow probe or in the form of a bypass arrangement.
  • a simple and timely monitoring of the real state of liquids in technological processes and, for example, in engines is possible by detecting a plurality of state-typical parameters, for example changes as a function of the operating time, the influence of temperature and pressure or other factors to capture.
  • a plurality of state-typical parameters for example changes as a function of the operating time, the influence of temperature and pressure or other factors to capture.
  • several parameters, such as ⁇ , n and the pH at the desired time can be detected simultaneously with a simple probe or measuring cell and a device; which is not possible according to the state of the art.
  • the conductivity ⁇ of liquids and the transit time T r of ions can be determined further parameters.
  • FIG. 1 shows an arrangement for measuring the electric current in liquids with a measuring resistor R m ;
  • Figure 2a shows an arrangement for measuring the electric current in liquids with a sample container with plate electrodes in section;
  • Figure 2b is a perspective view of the plate electrodes of
  • Figure 3 is a thermally and electrically isolated measuring chamber in section
  • FIG. 4a shows a coaxially formed measuring cell in section
  • Figure 4b shows the top view of the measuring cell according to Fig. 4a
  • FIG. 5 shows a measuring cell with pivotably arranged electrodes
  • Figure 6 is a schematic representation of a plurality of electrodes
  • Figure 7 is a schematic representation of a complex device concept for
  • FIG. 8 is a graphic representation of the time dependence of the measuring voltage, of distilled water, U m (t);
  • FIG. 9 shows the graph of the dependence of the average mobility ⁇ and the mean concentration n of the ions of the time t, of distilled water;
  • FIG. 10 is a graphical representation of the temporal dependence of the measuring voltage on the biodiesel, U m (t);
  • FIG. 11 shows the graph of the dependence of the mean mobility ⁇ and the mean concentration n of the ions of the time t, of the biodiesel;
  • FIG. 12 shows the graphical illustration of the time dependence of the measuring voltage,
  • FIG. 13 shows the graph of the dependence of the average mobility ⁇ and the mean concentration n of the ions of the time t, of the oil 04/2;
  • FIG. 14 shows the graph of the dependence of the average mobility ⁇ on different, respectively constant temperatures T cj and oil 04/2;
  • Figure 15 is a graph showing the dependence of the mean mobility ⁇ and the average concentration n of the ions of the time t, the waste oil 04/2;
  • FIG. 16 shows the graphical representation of the time structure of the original voltage of a
  • Fig. 1 shows a simple arrangement with an insulated measuring chamber M k in which the internal temperature of the measuring liquid T c can be measured with a temperature sensor T s . (Simplifies because the measuring cell dips into the liquid and unwanted secondary currents, eg from the back of the electrode, are neglected.)
  • the measuring cell M z is arranged, which is simplified by a plate capacitor.
  • the liquid S x from which the parameters are to be measured.
  • the arrangement further includes a variable measuring resistor R m , which can be adjusted by means of a resistance decade of 0 to 10 9 ⁇ .
  • the voltage drop at R m is measured with the digital voltmeter DV and from this the measurement current L is determined.
  • a current-voltage converter can be used or replaced by an oscilloscope or a pen.
  • a digital, fast and low-impedance ammeter can also be used.
  • the measuring cell M z and the measuring resistor R m form a series circuit which is parallel to the external voltage source U 0 .
  • the switch S e c can be achieved that the voltage source U c can be disconnected In this case, only the original voltage U e of the measuring cell M 2 would cause the flow of current when the switch S e , a is closed.
  • the voltage source, the switches S e , c , S e, a , the temperature sensor T 3 , the ammeter or R m and the DV or the other device variants and modules are connected via their interfaces S s to a PC, which detects the measured data , processes, stores and displays.
  • the measuring chamber M k according to FIG. 1 can be optimally realized by a sample container, similar to the known cuvette geometry, as shown in FIGS. 2 a and 2 b.
  • a liquid volume is filled; they are called volume measuring cells.
  • the immersion measuring cells which are simply immersed in the liquid.
  • the surfaces of the electrodes A 1 2 are connected at its rear side with the large wall surfaces of the container B by a screw thread and the electrical contacts are guided as lines L to the outside, at the same time eliminates the insulating spacers, which otherwise realize the constant distance d of the measuring cell help.
  • Different electrode spacings d become with such sample containers realized by differently thick electrodes or cuvettes, the Küvettengeometrie and thus the surfaces of the electrodes A 1 2 remain the same.
  • the symbols 1 and 2 in Fig. 2a are intended to indicate different levels of liquid; eg in cold or heat.
  • the two electrodes can be curved as a half cylinder and thus the measuring cup to be cylindrical.
  • the completed plan view i. cylindrical body with the electrodes, one would see a circle showing in the middle of a curved double slit, between which the liquid is located.
  • These two variants of measuring cells are also suitable as flow cells, if hose nozzles for inflow and outflow are still provided.
  • thermoglass similar to a cuvette, would at the same time enable the electrical insulation and the rapid heating or cooling of the liquid to be measured in a temperature-controlled bath.
  • Fig. 3 shows the outer measuring chamber M ka with the outer and inner insulation I and Isoi and a cover D 2 in more detail than described in Fig. 1.
  • the inner measuring chamber M kl for example, is realized by a good cold or heat-conducting container, which is filled with a liquid S x .
  • a measuring cell M z is immersed in the liquid S x to be examined. In this measuring cell, all other surfaces except for the active electrode surfaces are formed in isolation.
  • the space between the outer wall of the container B, for example a Schott beaker or a thermo glass cuvette , the inner insulation I 13O i and the lid D 2 is filled with the liquid S u , which generates the generated cold or heat from the cold heat Zone (KW zone) to the vessel B forwards.
  • the KW zone is realized, for example, by a copper coil through which a medium to be cooled or to be heated flows. With the second temperature sensor Ts, the bath temperature T is monitored bath and / or regulated.
  • the KW zone can also be realized, for example, as a heating element and / or as a Peltier element.
  • the electrical voltage U z is passed to the measuring cell M z and the current detected by the measuring cell l z .
  • the cover breakthrough D 3 intended. He can also serve to compensate for overpressure.
  • FIGS. 4a and 4b show, as a further example, another measuring cell variant M 2 which can be used as a submersible measuring cell or as a volume measuring cell. It consists of two coaxial stainless steel cylinders which dive into or through the liquid.
  • Fig. 4a shows the vertical section through the cylinder. The distance between the inner surface of the first, large cylinder and the outer surface of the inner, smaller cylinder is d.
  • the outer cylindrical surface of the inner cylinder (Zj) is: A 1 ⁇ A 2 , the inner cylindrical surface of the outer cylinder (Z a ).
  • FIG. 4b shows the top view of the coaxially executed measuring cell M 2 .
  • This variant can also be realized only by two half cylinders, which are behind each other and in the gap with the distance d, the liquid S x is introduced.
  • the insulating mounting elements for symmetrical cohesion, the inflow and outflow of a moving medium, the shielding and lining of the arrangement and the electrical lines have been omitted here.
  • the holders of immersion measuring cells or the bodies which, by mounting the electrodes, result in the defined volume of the volume measuring cells.
  • Fig. 5 illustrates a practical measuring cell which, by virtue of its construction, enables rapid cleaning after measurement since it has pivotally arranged electrodes.
  • the two pins St 1 and St 2 which run as an axis through the Teflon plates Tp, they are laterally pivotable.
  • the isolated retaining clip Hk must be solved, which holds both electrodes E 1 and E 2 in parallel.
  • the electrodes are held by the foot Fu.
  • the two spacer pins Dst made of Teflon ensure that the desired distance d is maintained.
  • the electrodes are inserted in the Teflon plates. As a result, essentially only the two electrode surfaces BF come into contact with the liquid.
  • the side surfaces and rear sides can also be made insulated (see FIGS.
  • the two lines L 1 and L 2 should be firmly connected to the electrodes and at the same time be isolated externally.
  • the electrode surfaces can now be cleaned well with suitable, solid woolen cloths and suitable aids, polished and rinsed under water. Subsequently, a dip (with and without ultrasound) has proven in losopropanol.
  • FIG. 6 very simply illustrates a multicell (Mmz).
  • Mmz multicell
  • the Mmz invention consists of four stainless steel plates, which are held together by long M4 plastic screws. Between the electrodes there are plastic washers through which the threaded screws pass. This arrangement is housed with the wiring and the four lead bolts (Lb) in a plastic housing Kg. This allows greater Urditionen (EMF's) are generated.
  • EMF's Urditionen
  • Fig. 7 is a schematic complex device concept for determining the
  • the device concept comprises one or two separate measuring chambers M ", which may be, for example, an integrated cooling and heatable arrangement, each with a measuring cell M z . With the other electronic components, the required voltages are provided and measured.
  • For measuring the cell current is at least one measuring resistor R m , whose
  • Voltage drop is measured very accurately and digitally.
  • Advantageous are several, freely selectable measuring resistors. In this way, the relatively expensive pA meter can be saved or it is a connection for the DA provided.
  • the constant and variable parameters can be stored, programmed, queried, calculated and controlled in a targeted manner.
  • the calculation and the display of the desired quantities are carried out automatically: the mean mobility ⁇ and the mean concentration n of the ions and the pH value. Furthermore, the electrical conductivity ⁇ can be determined.
  • a laptop could also serve as a PC, loaded with a CD containing software for the necessary commands and calculations.
  • FIGS. 8 to 18 The further description of FIGS. 8 to 18 is made in the individual embodiments. After describing the arrangement according to the invention, scientific relationships on which the functions of the arrangement and also of the method for determining the desired parameters of liquids are based are illustrated and explained below.
  • the electrical conductivity is not caused by electrons, but by ions (ion conduction). However, this is not primarily about electrolytic processes, but about ionic conduction in homogeneous and molecular substances, e.g. Water, aqueous solutions (such as beer and Coca-Cola), biodiesel, motor oil, waste oil, glycerol and petroleum, i. pure and undiluted. Used motor oil (waste oil) is a targeted exception.
  • the external electrical source supplies the series connection with a constant voltage U c , which consists of the measuring cell M z and the measuring resistor R m .
  • U c is the constant total voltage; U 2 is the cell voltage.
  • the transit time T r is adopted.
  • T n of the drifting ions between the two electrode surfaces A 1 and A 2 which may be the same or different (see, for example, FIG. 2 b and FIGS. 4 a and 4 b).
  • T r transit time equal running time of the drifting ions between the
  • ⁇ the mean mobility of the ions d distance of the electrodes
  • E z the electric field strength in the measuring cell M z .
  • the electrical conductivity ⁇ z in the measuring cell M z is:
  • n, ⁇ b> Z i / (e * ⁇ j) and, Eq. 9b
  • the pH can be found in the well-known Sörenson term:
  • H + is the numerical value of the molar hydrogen ion activity H + .
  • the measured current l m , the electric field strength E z , the mean mobility ⁇ , the mean ion concentration n, the pH value and the conductivity ⁇ are related to U e and processed by software.
  • Embodiment 1 Disistilled water, Dw OD
  • a modified arrangement according to FIG. 1 is used.
  • a measuring resistor of 100 ⁇ (or less) is used, and then the voltage dropping with a high-impedance digital voltmeter (DV, eg of the type: Digitek DT80000, company: Elektronik Literatur Verlag (ELV)) measured over the RS-232 interface is connected to the PC.
  • the switch S e, a in Fig. 1 is replaced by a polarity reverser, which allows the alternating operation of the measuring cell with +/- U z and the intermediate short circuit (this was a self-constructed "Viskosi") Performance data: 96V / 0.6A used.
  • the temperature variation and stabilization was confirmed by means of a CT 52 transparent thermostat and a CK 300 flow cooler, Schott AG. In the water bath of the thermostat hung a stainless steel cup with lid, which was filled with Slikonöl and in which stood the beaker with the probe.
  • the silicone oil was used to exchange the temperature between the water bath and the inside of the beaker, for storage in the event of short-term temperature fluctuations (and for extending the possible creepage distance from the water bath to the measuring substance).
  • the measuring chamber M k (in this example a beaker) was filled with approx. 125 ml of distilled (pure) water (Dw 01).
  • the (cleaned and dust-free) measuring cell M z was immersed, which is designed here as a plate capacitor.
  • the surfaces facing away from the electrodes were not yet isolated in this example. It has proven to be advantageous that the container, as shown in Figs. 2a and 3 (see D 2 ), is tightly covered to prevent dusting, evaporation or interaction with the ambient air of the liquid.
  • Fig. 8 first shows the typical U m (t) - course of distilled water at this DC voltage and temperature.
  • the two quantities ⁇ (tj) and n (t) are plotted as functions of the time (tj, at the same time the x-axis) PC-supported in an x, y-diagram.
  • the superposition of the two functions ⁇ , (t) and ni (t) in a diagram creates a defined intersection point. It has been found that this corresponds at the temperature T CJ and U z ⁇ or R n , just the transit time T r .
  • This quantity is provisionally used as a reference for the parameters: ⁇ , n, ⁇ and pH. See eg Fig. 9.
  • the applied total voltage U 0 was set to 4.00 V.
  • the accuracy of the method can be further increased by e.g. A high-quality digital desk-top multimeter (from the company Fluke 8845A, for example) is used, which records 100 or more measured values in one s and allows the data to be transferred to the PC.
  • a high-quality digital desk-top multimeter (from the company Fluke 8845A, for example) is used, which records 100 or more measured values in one s and allows the data to be transferred to the PC.
  • the application of a pole reverser with an intermediate short circuit enables reproducible measurements, as this reduces the problem of polarization.
  • the pole turner e.g., a commutator or relay, and at the same time a short circuiter
  • a special square-wave generator which in particular can deliver variable amplitudes, long pulses, and the intermediate short-circuit of the measuring cell.
  • Exemplary embodiment 2 biodiesel, Bd 06 (commercial fuel)
  • T CJ constant temperature
  • the diagram according to Fig. 10 shows the typical profile of the measurement voltage U m (t) from the biodiesel _229- K20 06 30.02 at 0 C.
  • the measured resistance was 100 k. This was explained in detail as in the embodiment 1 (Dw 01), according to the new method, Fig. 11 won.
  • the values of ⁇ and n can also be detected at a different time t.
  • the determination of the pH value is not bound to the transit time T r in that the method according to the invention also makes it possible to determine the transit time T r , is another advantage of this method.
  • Exemplary embodiment 3 oil 02/4 (commercial motor oil, type: 10 W-40)
  • This used oil was a commercial motor oil, of the type: 10W - 40 in the freshness state. It was created after 20,000 km mileage of a small delivery truck.
  • the following table compares typical parameters of fresh oil and used oil. Table 1 Parameter comparison of fresh and used oil 04/2 (after 20,000 km)
  • the desired liquid parameters can be determined and displayed automatically in the shortest possible time.
  • the further exemplary embodiments relate to the case where the external voltage U c is zero and only the primary voltage U e of the measuring cell M z causes the current. Furthermore, the determined parameters are not superficially related to the transit time but to arbitrary times.
  • FIG. 16 shows the structure of a primary voltage or electromotive force (EMF), which was created by immersing a multi-measuring cell (Mmz) in a pH 4.00 buffer solution (from Metrohm).
  • EMF electromotive force
  • Mmz multi-measuring cell
  • pH 4.00 buffer solution from Metrohm.
  • the features of this Mmz are (see also Fig. 6): four stainless steel plates of almost 17 cm 2 , which are arranged parallel and opposite, so that 3 chambers can form. In each corner there was a hole of 4.2 mm 0.
  • fasteners were 4 pieces M4 plastic screws and as a distance same plastic washers.
  • the two outer electrodes are connected from behind with a rear wall made of PVC.
  • the plastic screws hold the arrangement firmly together with the end nuts.
  • the remaining interconnection is shown in FIG. 6.
  • the distance between the electrodes was 0.08 cm and the total effective area (ie, without the four holes) was 43.67 cm 2 .
  • the total chamber volume of the Mmz was 3.45 cm 3 .
  • the original voltage is retained even after several measurements. If the switch S e, a is turned on, then the original voltage U e discharges via R m , and with the aid of the deconvolution ⁇ and n can be determined separately.
  • FIG. 17 shows such a case with this Mmz.
  • This was immersed in pH 7 buffer and gave such EMK of 129.2 mV. (The sign can be changed by the apparatus).
  • the pH was checked with a device 827 pH lab Metrohm. At 27.48 0 C it was 7.01.
  • the deviation is due to the fact that the measuring cells still need to be optimized in order to increase the original voltage, resulting in a larger discharge current.
  • the example also illustrates that by this method, the pH can be determined directly without the known calibration curves, as is known in the art. According to this method, the pH measurement is - in contrast to the known methods of the prior art - attributed to the determination of the sizes ⁇ and n, from which immediately follows the pH.
  • a digital ammeter (DA) is also suitable for determining ⁇ and n from the electrical conductivity and the original voltage U e .
  • FIG. 18 shows measurement results for a number of liquids, including glycerol and petroleom.
  • a m average electrode area from A 1 , A 2 mA current unit, milliampere pA pico ammeter
  • B container or vessel e.g. Glass mug or a rectangular cuvette
  • Hk an isolated clamp that holds together eg two electrodes IF isolated areas, l m measuring current, l mi measuring current, at time t "l z electric current, through the measuring cell,
  • n mean ion concentration ions, n s the saturation concentration, n opt optical refractive index
  • R m variable measuring resistor eg 10 ⁇ or 100 k ⁇
  • St 1 pin (as a rotation axis)
  • U m (t) is the time-dependent measurement voltage

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Abstract

L'invention concerne un ensemble et un procédé pour déterminer des paramètres d'un liquide, la mobilité moyenne µ et la concentration moyenne n des ions et la valeur pH. Le procédé est effectué à une température constante (Tc) et à une tension totale constante (Uc), égale ou pouvant être égale à zéro, appliquée à une chambre de mesure (Mk) dotée d'une cellule de mesure (Mz) contenant le liquide à tester (Sx) et d'au moins deux électrodes (E1, E2) séparées d'une distance parallèle (d) et pourvues de surfaces (A1, A2), et consiste à d'abord déterminer une tension de mesure (Um) appliquée à une résistance de mesure (Rm), à définir une intensité de mesure (lmi) dans un temps de cycle (ti) défini et, à partir de la tension totale Uc prédéfinie et de la tension mesurée (Um) sur la résistance de mesure (Rm,), à déterminer la tension (Uzi) de la cellule de mesure; puis à déterminer l'intensité du champ électrique (Ezi) et enfin, comme autre paramètre du liquide, la mobilité moyenne des ions µi et/ou à déterminer la concentration moyenne des ions ni en tant que paramètre du liquide puis la conductivité électrique (sa,zi) et, à l'appui de la mobilité moyenne des ions µ?, à déterminer la concentration moyenne d'ions n, et/ou à déterminer, comme autre paramètre du liquide, la valeur pH à l'appui de la concentration moyenne d'ions ni.
PCT/DE2010/000659 2009-06-08 2010-06-08 Procédé et ensemble pour déterminer des paramètres d'un liquide Ceased WO2010142282A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE112010002357T DE112010002357A5 (de) 2009-06-08 2010-06-08 Verfahren und anordnung zur bestimmung von flüssigkeitsparametern
EP10734436A EP2457084A1 (fr) 2009-06-08 2010-06-08 Procédé et ensemble pour déterminer des paramètres d'un liquide

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102009024937.0 2009-06-08
DE200910024937 DE102009024937A1 (de) 2009-06-08 2009-06-08 Verfahren und Anordnung zur Bestimmung von Flüssigkeitsparametern

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