WO2010142282A1 - Method and arrangement for determining liquid parameters - Google Patents

Abstract

The invention relates to an arrangement and to a method for determining liquid parameters, the average mobility μ and the average concentration n of ions and of the pH-value. The method is carried out at a constant temperature (T_c) and at a constant total voltage (U_c), which can be zero or different from zero, and is used in a measurement chamber (M_k) having a measurement cell (M_z) containing the liquid to be tested (S_x) and at least two electrodes (E₁, E₂) which are separated from each other at a parallel distance (d) and provided with surfaces (A₁, A₂). According to said method, initially a measurement voltage (U_m) applied to a measurement resistor (R_m) is determined and a measurement flow (l_mi) in a defined cycle time (t_i) is determined and then, from the predefined total voltage U_c and the measured voltage (U_m) on the measurement resistor (R_m,) the measurement cell voltage (U_zi) is determined, followed by the determination of the electric field strength (E_zi) and finally, as an additional liquid parameter, the average mobility of the ions μ_i and/or for determining the average ion concentration n_i as a liquid parameter, initially the electric conductivity (σ_a,zi) is determined and the average ion concentration n is determined using the average mobility of the ions μ_ι, and/or the pH value is determined as an additional liquid parameter using the average ion concentration n_i.

Description

 Method and arrangement for determining liquid parameters

The invention relates to a method and an arrangement for determining the mean mobility μ 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. Here, the migration speed is determined only by a kind of ions having a certain color. For example, ^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 μ positive and negative charged ions using an optical method for detecting small volume differences. This method has a scientific rather than an applicative meaning.

According to the technical solution disclosed in patent specification DD 156 846/2 /, the electrophoretic mobility and the radius of a giant ion were determined by means of a

Microscope determined.

However, all these optical methods are not applicable to small and especially colorless ions, eg H ⁺ or OH ^' , since the velocity and the radius of

Quantum sizes can not be determined with optical methods because of the uncertainty principle. To determine the concentration of ions, the dimensional analysis, also called volumetry, offers. In this method, 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).

According to the Debye-Hückeltheorie (page 343, in IM), individual ion activities a ⁺ or a ^" or individual activity coefficients can not be determined experimentally According to this theory, only mean ionic activities or only average activity coefficients can be determined The activity coefficient of a single ion species is not measurable ,

The term pH was first proposed by Paul Lauritz Sörensen in 1909 (Comptes-Rendus of the Travaux du Laboratoire de Carlsberg 8me Volume Ire Livraison, Copenhague, 1909/47). Over the past 100 years, this process has become a recognized pH measurement technology with multiple applications in industry, chemistry, biology and medical technology.

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.

In summary, it is known that in an aqueous liquid there are positive and negative ions which generally have different mobilities and concentrations. However, they all contribute more or less to the flow of electricity. To determine the pH, 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. In this respect, 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.

From DE 103 58 354 B4 / 9 / there is a pH probe, which is characterized by a special structural design of the housing, are arranged in the pH electrode and reference electrode.

DE 10 2007 034 886 B4 / 10 / discloses an optical measuring method for determining the pH. By irradiation of the pH indicator with fluorescent light and its detection, a measure of the pH of the medium was found.

With the prior art presented here, however, only the pH value can be determined as the liquid parameter. Other fluid parameters, such as the mean mobility μ and the average concentration n of a lonenart, are not determinable with these technical solutions.

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.

Furthermore, 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 μ 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.

According to the invention the object is achieved by a method for the determination of liquid parameters, the average mobility μ 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

l _m , = l ₂ = U _m , / R _m GI.1

is determined and then from the predetermined total voltage U _c and the measured voltage U _m on the measuring resistor R _m the measuring cell voltage U ₂ , after

U _z , = U _c - U _m , GI.2

where U _c = 0 or ≠ 0,

is determined and then the electric field strength E ₂ , after

E ₂ , = U _zl / d Eq. 3

wherein U ₂ , the cell voltage at time t, and d is the distance of the electrode surfaces A ₁ and A ₂ ,

finally, it is determined as a liquid parameter the mean mobility of the ions μι according to the relationship

μ, = d / (t, * E ₂₁ ) Eq. 4

where t, the tact time from i = 1 to n,

and / or for determining the mean ion concentration n, as a further liquid parameter, first the electrical conductivity σ _a , _zl according to the relationship

σ _a , z, = (l _m , / A _m ) / (U _z , / d) Eq. 5

where A _{m is} the mean electrode area A _m = (A ₁ + A ₂ ) / 2, e is the elementary _charge and l _mι the measuring current at time t,

is determined and based on the mean mobility μ, the ions, the average ion concentration n; after the relationship

n _d , = σ _zι / (e μ μ _dl ) Eq. 6

where i = 1 to n,

is determined and / or as a further liquid parameter on the basis of the mean ion concentration n, the pH value of the relationship

pH K - Ig [In (t,) l / (6.02214 ^* 10 ²³ )] Eq. 7

is determined, in which In (t,) l the average ion concentration at time t, dimensionless and in cm ^"3 is used and the size 6.02214 * 10 ^{23 is} the Avogadro constant.

A particularly preferred embodiment of the method according to the invention provides that at U _c = 0, a current flow l _{z is} caused solely by a primary voltage U _{e of} the measuring cell M _z . According to an advantageous embodiment, 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.

Furthermore, an embodiment provides that the total voltage U _{0 can be applied} as a constant alternating voltage with a constant or variable frequency.

Advantageously, temporally variable voltages or voltage pulses with the amplitude ± U _C , arbitrary pulse shapes and / or frequencies can be applied.

According to a further embodiment of the method, the intervals Δt of the cycle times t, constant or freely selectable values are used as intervals Δt.

According to the invention, 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 ,

Has a _z to the measuring cell M connected to the electrical module, which supplies the measuring cell M _z with a total electrical voltage U _0, which may be zero or different from zero, the _ae a switch S and a switch S _ec or only one switch S _ae - and has means for measuring the electric current I _m = I _z conducted through the measuring cell M _z , wherein - The measuring chamber M _k , the voltage source U _c , the switch S _ae , and S _e , _c , the temperature sensor T ₅ , the means for measuring the electrical current l _m via interfaces with an evaluation unit with a computer program and a display for detecting and Storage of all collected data and for calculating and displaying the parameters of the liquid are connected.

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.

According to a further embodiment of the arrangement, the surfaces A ₁ and A _{2 of} the electrodes E ₁ and E ₂ are flat or curved and preferably formed as plates of the same or different geometric shape, as a half-cylinder or as a cylinder and the size of the electrode surfaces Ai = A ₂ or A ₁ not equal to A ₂ and the electrodes E ₁ and E _{2 have} a similar or different material properties and / or coated with similar or different materials.

Advantageously, 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.

According to another embodiment, the measuring chamber M _k can be heated or cooled directly or indirectly.

Preferably, the electronic module is equipped with software for calculating, storing and displaying the liquid parameters.

According to another embodiment, R _{m has} a value of up to 10 ⁹ Ω.

Preferably, the measuring chamber M _k or the entire arrangement are shielded against electromagnetic influences.

According to the invention, 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.

It is an outstanding advantage of the invention that with the provided method and the arrangement according to the invention several parameters of liquids can be determined at the same time regardless of whether they are thin or viscous and dirty or almost anhydrous.

With the aid of the invention, 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. For this purpose, it is advantageous that several parameters, such as μ, 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. In addition, with the arrangement and method, the conductivity σ of liquids and the transit time T _r of ions can be determined further parameters.

In the following, the invention will be explained in more detail with reference to drawings and exemplary embodiments. Show it:

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

Sample container according to Fig. 2a;

Figure 3 is a thermally and electrically isolated measuring chamber in section;

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

Measuring cell; Figure 7 is a schematic representation of a complex device concept for

Measurement of different fluid parameters; 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 μ 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 μ 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,

U _m (t), from oil 04/2; FIG. 13 shows the graph of the dependence of the average mobility μ 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 μ on different, respectively constant temperatures T _{cj and} oil 04/2; Figure 15 is a graph showing the dependence of the mean mobility μ 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

Multicell in a pH 4 buffer; 17 shows the graph of the dependence of the mean mobility μ and the mean concentration n of the ions of the time t from the buffer with pH 7; FIG. 18 Tabular summary of measurement results of various

Liquids and the indication of their typical parameters;

First, arrangements are described with the figures 1 to 7, which consist of individual devices, modules or elements with which the method for determining the desired parameters can be operated.

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.)

In the measuring chamber M _k , the measuring cell M _{z is} arranged, which is simplified by a plate capacitor. Here are two identical and flat stainless steel plates with the electrode surfaces A _{1 2} - parallel and at a distance d - arranged directly to each other. In between is 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 Ω. Furthermore, the voltage drop at R _{m is} measured with the digital voltmeter DV and from this the measurement current L is determined. Also, a current-voltage converter can be used or replaced by an oscilloscope or a pen. Instead of a measuring resistor and DV, 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 . With 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. The measuring cell M ₂ is here formed by the electrodes A _{1 2 are} attached to the two large inner surfaces of the container B, which may for example consist of Teflon or glass. In this way, one also obtains a defined internal volume of the measuring cell V ₂ = Ai ₂ ^* d, which can also be minimized in this way. In this type of measuring cell, a liquid volume is filled; they are called volume measuring cells. In contrast to the immersion measuring cells, which are simply immersed in the liquid. If 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.

In the case of this measuring cell variant (see FIG. 2b), all the surfaces except the opposing electrode surfaces Ai and A ₂ could additionally be formed in isolation. On the other hand, the latter are brightly polished surfaces BF. In this illustration, the visible surfaces are also marked with IF.

Also, the two electrodes can be curved as a half cylinder and thus the measuring cup to be cylindrical. In 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.

A transparent sample container made of 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. In this view, two spacers, arranged here as dashed lines between the electrodes of the measuring cell M _z . With the two temperature sensors T ₅ , the temperatures in the vicinity of the electrodes and those of the bath are measured. 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.

With the electrical lines L, the electrical voltage U _{z is passed} to the measuring cell M _z and the current detected by the measuring cell l _z . For 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. In this arrangement, since the electrode surfaces are different, 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. For simplicity, 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. Likewise, 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. By the two pins St 1 and St 2, which run as an axis through the Teflon plates Tp, they are laterally pivotable. For this purpose, the isolated retaining clip Hk must be solved, which holds both electrodes E ₁ and E _{2 in} parallel. Also, 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. For safety's sake, the side surfaces and rear sides can also be made insulated (see FIGS. 2b, IF). The two lines L ₁ and L ₂ should be firmly connected to the electrodes and at the same time be isolated externally. In the opened state, 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). Here, four electrodes were combined, which together yield three measuring cell chambers. The two horizontal Axes are used for cohesion and distance adjustment. 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 Urspannungen ^(EMF's) are generated. In practice, these multi-cells can also be provided with the advantageous pivoting mechanism.

In Fig. 7 is a schematic complex device concept for determining the

Fluid parameters shown.

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.

About the individual _interfaces all required parameters, such as U _c , l _z or U _mι , T _q , tj (measuring time), etc. digitally recorded and the constant sizes, such. As date, time, S _x , R _m , etc. entered.

By means of an electronic control module or microprocessor M _d , the constant and variable parameters can be stored, programmed, queried, calculated and controlled in a targeted manner.

At the end, the calculation and the display of the desired quantities are carried out automatically: the mean mobility μ and the mean concentration n of the ions and the pH value. Furthermore, the electrical conductivity σ can be determined.

A laptop could also serve as a PC, loaded with a CD containing software for the necessary commands and calculations.

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.

Experimental and theoretical investigations on numerous high and low ohmic liquids have found that they meet Ohm's law of electricity in a relatively large and individual voltage range. This makes them very similar to the electrolytic solutions.

In liquids, 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.

In the following, known equations are used:

According to FIG. 1, 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 = U ₂ + U _mi Eq. 2a

in which mean:

U _{c is} the constant total voltage; U _{2 is} the cell voltage.

If, in FIG. 1, the switch S _{e, c is} in the position c and the switch S _{ea is} closed, then an electric current flows, that is the measuring current l _m . For him: I _n , = U _c / R ₂ , if the low-ohmmeter is in series. Or, if according to FIG. 1, the measuring resistor R _{m is} in series:

l _m = U _m / R _m . Eq. 1 The electric field strength E ₂ in the measuring cell M _z is determined by the cell voltage U ₂ and the distance between the electrodes d. The following applies:

E _zi = U _zi / d, Eq. 3

in which mean:

E _zι the electric field strength E _z , in the measuring cell M _{z ,;}

U _zι the cell voltage d distance of the electrodes.

Now, based on solid-state physics, the concept of the transit time T _{r is} adopted. Here, it is the transit time 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). By definition, then:

μ = d / (T _r * E _z ) => _Mi = d / (ti * E _zi ), GI. 4

in which mean:

T _r transit time, equal running time of the drifting ions between the

electrodes; μ the mean mobility of the ions d distance of the electrodes; E _{z is} the electric field strength in the measuring cell M _z .

And if all quantities are related to t, then Eq. 4th

The electrical conductivity σ _z in the measuring cell M _z is:

σ _a , zi = J zi / E _zi = (I ₂ / U ₂ ) * (d / A) Eq. 9a

in which mean:

J _Zι the current density of the cell current I _{2 ,,} through the electrode surface A;

U _zι the cell voltage, in the measuring cell M ₂ ;

E _zι the electric field strength in the measuring cell M ₂ ; d / A is the cell constant of the measuring cell M _z , where d is the distance between the electrodes and A of the electrode surface, or the electrode surfaces.

And for σ _az , another, identical relation is known:

σ _b , zi = e * rij * μ, - which when transformed is the equation:

n, = σ _{b> Z} i / (e * μj) and, Eq. 9b

where: n, the mean ion concentration and: σ _blZι the electrical conductivity in the measuring cell M _z ; e the elementary charge; μ, the mean ion mobility.

The pH can be found in the well-known Sörenson term:

where a _H ^{+ is} the numerical value of the molar hydrogen ion activity H ⁺ .

As is known, it is known that in dilute solutions the hydrogen ion activity comes close to the hydrogen ion concentration, thus also:

pH "- Ig [Inj / (6.02214 * 10 ²³ )]. Eq. 7

wherein the amount of the mean ion concentration ln (t,) l is dimensionless and in cm ^"3 and is related to t, and the size (6.02214 * 10 ²³ ) is the Avogadro constant.

If σ and the pH value are to be measured in one flow, the influence of the flow velocity on the internal velocity v or on μ has to be considered.

When the switch S _{ec is} closed, then at the same time the external voltage source U _{c is} disconnected. In this case, the current flow through R _m or by the Ammeter caused solely by the original voltage U _e . This gives, in analogy to Eq. 2 the Eqs. 2 B:

U _e = U _z = U _m . Eq. 2 B

As a result, the measured current l _m , the electric field strength E _z , the mean mobility μ, the mean ion concentration n, the pH value and the conductivity σ are related to U _e and processed by software.

The determination of the desired parameters in this condition is analogous to the case that U _c ≠ 0.

In the following, the invention will be explained in more detail with reference to exemplary embodiments.

Embodiment 1 (Distilled water, Dw OD

For measurement, a modified arrangement according to FIG. 1 is used. For the pico-ammeter, a measuring resistor of 100 Ω (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).

By means of an integrated temperature sensor with glass coating (eg TFX 430, the company ebro) was additionally and continuously the temperature of the Dw 01 and thus the Liquid layer inside the measuring cell M _z and in the beaker exactly measured at two places behind the comma.

The measuring chamber M _k (in this example a beaker) was filled with approx. 125 ml of distilled (pure) water (Dw 01). In it, 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.

The further explanations relate to FIG. 8, with the graphical representation of the data from the measurement: U _m (t) _211-K 2 of Dw 01. Therein, the time profile of the measuring voltage U _{m is} shown and on the y-axis based. At an external DC voltage U _c of 4 V, the measuring voltage U _m (t) dropped on a measuring resistor of 100 Ω, which was in series with the measuring cell M _z . And as x-axis time is plotted; In this case, a measurement was carried out in 1s (sampling interval 10).

It will now be shown with reference to FIG. 8 and the following FIG. 9 how the transit time T _r can be determined by the method according to the invention from the course of U _m (t):

Fig. 8 first shows the typical U _m (t) - course of distilled water at this DC voltage and temperature.

Now 50 adjacent times are selected on the x-axis of FIG. 8 (starting with i = 1, 2, 3 s, etc.). An Excel spreadsheet was used to measure U _m (t) _211-K2. It was digitally recorded by the PC during the measurement and contains two columns, the time of the measurement and the amount of the measurement voltage. With the help of U _m , and (Eq 2a). can then be easily determined U _2i , because U _{c is} known and constant. Likewise, let l _Zι = l _m by the knowledge of R _m and U _mi according to Eq. 1 determine.

Then with the help of Eq. 3, 4, 2a and 1 E _zi and μ _d i (t) as a function of t, for i = (1, 2, 3, ... to 50) s. From the variables U _zi , l _z , and the cell constants for A _{1 2} and d (see above) can be calculated according to Eq. (9a and 9b) σj and nι be easily calculated because μι (tj) previously with the Eq. 4 has already been determined. This is done by a programmed Excel spreadsheet that performs the equations. At the end, a table extract can be created from it, which again contains t "and μ, as well as n, and for a diagram formation suitable is. For this purpose, the two quantities μ (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 μ, (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 _zι or R _n , just the transit time T _r . This quantity is provisionally used as a reference for the parameters: μ, n, σ and pH. See eg Fig. 9. The exponential decay curve shows μ (tj) and the increasing function n (ti). It was determined in the measurement (211-K2) the corresponding time of the intersection of both functions at 20.67 ^C C, it was T _n = 35.05 s. Here, the applied total voltage U _{0 was set} to 4.00 V.

At the end of this embodiment, it will be shown how σ and the pH value can be determined with the new method. To obtain σ two ways are shown. In the first way in the Eq. 9a, the parameters U _z and l _{z are used} at T _r and d and A. But in order to use U _z , first U _m (T _r ) must be determined from the diagram of FIG. 8. This gives: U _m (T _r ) = 547.36 mV. By changing the Eq. 2a follows U _z = 3.4526 V, as the cell voltage at time T _r . With the help of Eq. 1 l _z = l _{m is} determined. This gives 5.4736 μA. And now these parameters can be converted into Eqs. 9a are used and one obtains for the measurement (211-K2): 5.17 μS / cm. In this and the other examples of Dw 01, the plate spacing d = 0.083 cm and the electrode area, each A _{1 2} = 25.46 cm ² .

In the second way, the parameters μ and n determined by the new method are read from FIG. 9 and expressed in Eq. 9b used. And this results in a simple possibility of calculating σ, since at T _r both numerical values (μ and n) differ only by their units and can be read in the μ, n diagram according to FIG. 9. The results are: μ = 5.66 ^* 10 ⁵ cm ² / Vs and n = 5.66 * 10 ⁺¹⁷ cm ^"3. This yields, with equation 9b: σ (T _r ) = 1.6022 ^* (Iμl or InI) ^{2 *} (10 ^{("19 + x + y)} ) * S / cm,

where x corresponds to the 10 ^{'of an} exponent of μ and y corresponds to the 10 ^{' of an} exponent of n.

Thus: σ (T _r ) = 1.6022 ^* (5.66) ^{2 *} 10 ⁷ S / cm = 5.132 μS / cm. (The small deviation of both σ values is attributed to the two-fold, manual removal of the parameters from the diagrams and the intermediate calculations). A first relative pH can already be found by looking for the time t = 0 on the x-axis and reading n (t = 0) at this point. We find for t = 0 n = 0.21 * 10 ¹⁷ cm ^"3, which gives us the following equation: pH = 7.46, but if we evaluate n (T _r ) we get: 5.66 * 10 ¹⁷ cm ^{~ 3} , and from this pH = 6.03.

Comparative measurements on fresh (deionized) water (for example Dw 01) gave the following pH measurement results with the devices mentioned here:

1. Hanna Instruments, type HI 120 with the electrode: HI 1053, at 20.2 ⁰ C pH = 6.134.

2. WTW, type pH 91, with the probe Bioblock (90431), at 21, 3 ⁰ C pH = 6.14.

(The small deviation of the pH measurements between the standard instrument method (see 1. and 2.) and the new method is also attributed to the fact that in this experiment the electrodes on the side surfaces and on the back are not isolated and therefore not optimal were.)

The necessary calculations were first carried out with a scientific calculator (of the type: hp 33s) and then on the PC - by extension and programming of the above - mentioned Umi - tj - Excel tables. The time taken to evaluate a measurement can be shortened even further with the help of suitable software and / or a microprocessor so that the results are available immediately at the end of a measurement (for example after a few seconds or minutes).

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.

Now the following important additions to the procedure have to be made concerning the polarity of the voltage:

At the beginning, a constant DC voltage was assumed, without paying attention to the sign of the voltage. But with constant current direction, known polarization effects generally form, which have a disruptive effect on the measurement. However, since a precise time constant T _{r is} required, it has been found that it is advantageous when working with alternating direct voltages. That is, the measurement is started with a constant, positive or negative DC voltage. A few seconds or minutes after the duration of the measurement, the measuring cell is short-circuited to neutralize the inner polarization field again. At the beginning of a new measurement, the short circuit is canceled again and then with the same voltage amount, but with opposite sign, etc., continue working. At the end, the mean value is calculated from the measured values.

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) can, of course, be replaced by a special square-wave generator, which in particular can deliver variable amplitudes, long pulses, and the intermediate short-circuit of the measuring cell.

In Fig. 18, these and other measurement results, including other liquids listed.

Exemplary embodiment 2 (biodiesel, Bd 06 (commercial fuel))

The measuring arrangement and the sampling took place as already explained in the exemplary embodiment 1. Again, a constant temperature (T _CJ ) in the beaker is assumed.

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. To determine the transit time T _r , attention should be directed to FIG. 11, the μ / n diagram of Um (t) _229-K20 (FIG. 10). Is obtained from this graph at 30.02 ⁰ C, for example, the following parameters: T _r = 18.65 s, μ (T _r) = 4.9731 ^* 10 ^"5 cm water and n (T _r) = 4.9731 * 1O ^{+ 13} cm ^3. However, the values of μ 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.

It will now be shown how the new process can be used to determine σ and the pH. To obtain σ (from the measurement: 229-K20), Eqs. 9b, the parameters μ and n are used, which can be read from FIG. 11 at T _r . The parameters μ (T _r ) and n (T _r ) and Eq. 9b: σ (T _r) = 0.396 ^* 10 ^-9 S / cm.

Then, in Fig. 9, n at (t = 0) and n (t = T _r ) are read. With the help of Eq. 7 and the onset of the respective InI, one obtains: pH = 10.78 or 10.08 at T _r . Further parameters for biodiesel 06 are contained in FIG. 18.

Exemplary embodiment 3 (oil 02/4 (commercial motor oil, type: 10 W-40)

The sampling, the determination of the transit time and the μ and n parameters were carried out analogously, as set forth in the exemplary embodiments 1 to 2.

In FIG. 12, the course of Um (t) _241-K19 from the oil 02/4 34,84 ⁰ is shown at C. In this measurement, the total voltage was -12.00 V and the measuring resistor was 100 kΩ. In Fig. 13 again μ and n are shown as a function of time. In this case, a measurement was carried out every 5s. The results at 34.84 ⁰ C are: T _r = 36,29 s, the associated transport parameters can be derived from the diagram of FIG read. 13. They are: μ = 1, 6774 ^* 10 ^"5 cmWs and n = 1, 6774 ^* 10 ⁺ 14 cm- ³ .

In Fig. 14 of this lubricating oil is still μ = f (T _cj ) shown. One recognizes well the typical, exponentially increasing mobility with increasing temperature.

Similar to biodiesel, the following parameters were determined by oil 04/2: μ, n, σ, T _r and the pH value. These parameters are listed in the table, as shown in FIG.

Exemplary Embodiment 5 (Car Waste Oil Which Was Oil 02 in Fresh State)

The sampling, the determination of the transit time and the μ and n - parameters were carried out, as already detailed in the embodiments 1 to 4.

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)

In FIG. 15, this process for used oil μ and n at 25.01 ⁰ C has been obtained and shown. Their and further parameters are listed in FIG. 18.

With the invention it is for example possible to derive the change of the oil in engines depending on the change of objective factors and not more - as is often still the case - from empirical values.

For example, accidents on internal combustion engines and on wind turbines are known in which gearboxes have been destroyed, even though the measured viscosity values of the oils used were still in the "operating range." The changes in the parameters μ n and, above all, the pH value that can be detected with the aid of the invention and in addition to σ and T _r , depending on the operating time and the operating temperatures, it is possible to objectify the necessity of an oil change and to avoid long-term damage.

With the aid of a software which is part of the arrangement according to the invention, 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). 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. As 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 μ 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). Furthermore, the pH was checked with a device 827 pH lab Metrohm. At 27.48 ⁰ C it was 7.01. The unfolding after 12s and an R _m of 100Ω gave an average concentration of the ions of n = 1, 48 ^* 10 ¹⁶ cm ^'3 . Actually, this size should have been 5.87 ^* 10 ¹⁶ cm ^{~ 3} . 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. However, 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 μ and n, from which immediately follows the pH.

A digital ammeter (DA) is also suitable for determining μ 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. REFERENCE NUMBERS

A ₁ , A ₂ electrode surfaces

Acs an axis

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

BF Blank polished and conductive electrode surfaces

cH ⁺ hydrogen ion concentration d electrode spacing e elementary charge

DA Digital Ammeter

DV digital voltmeter

D ₁ Insulating spacers between the electrodes, equal to d

D2 Lid of the measuring chamber

D ₃ opening for bushings,

Dst isolated pins that keep two electrodes at a constant distance

E _c constant, electric field strength

E _z electric field strength in the measuring cell

E _zi electric field strength in the measuring cell,

E ₁ electrode

E ₂ electrode

Foot A foot in which two electrodes are laterally, rotatably mounted

Eq. x equation with the number x

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,

Iso Thermally and electrically insulated measuring chamber

Isoi inner wall of the insulated measuring chamber

J _z current density, in the measuring cell

Kg plastic housing

KW cold-heat elements,

L electrical conductor or lines,

Lb bolt,

M _d module

M _κ measuring chamber

Mmz measuring cell with more than 2 electrodes

M _z measuring cell, n mean ion concentration ions, n _s the saturation concentration, n _opt optical refractive index

R _m variable measuring resistor, eg 10 Ω or 100 kΩ

R _z Ohmic resistance of the measuring cell

S _e , _a switch,

S _{e, c} switch

S _s interface to PC or notebook

St 1 pin (as a rotation axis)

S ₁₁ Ambient bath, for temperature compensation

S _x measuring liquid, general or liquid substance tj time parameter, t _m measuring time or measuring time T _b impulse width of the rectangular pulse (eg +/- U _c )

T _bath bath temperature in a measuring chamber

T _c constant temperature

T _cj constant temperature _values with index

Tp Teflon plate,

T _r transit time

T _s temperature sensor

U _c controllable, constant voltage source,

U _e original voltage source also as electromotive force (EMF),

U _n , measuring voltage

U _m (t) is the time-dependent measurement voltage

U _mi measuring voltage at time t,

U _z voltage applied to the measuring cell

U _zj voltage applied to the measuring cell at time t ,, v average velocity of the ions,

V ₂ Volume of the measuring cell

Z _a outer stainless steel cylinder

Zj inner stainless steel cylinder μ average mobility of ions σ Electrical conductivity, general

Claims

1. A method for determining liquid parameters, the average mobility μ and the average concentration n of ions and the pH, characterized in that at a constant temperature (T _c ) and a constant total voltage (U _c ), the zero or different can be zero, and at 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) from each other electrodes (E ₁ , E ₂ ) with the surfaces (a _1, a ₂₎ is applied, first a measurement voltage (U _m) at a measuring resistor (R _m) is detected and in a defined cycle time (tj), a measurement current (l _mi)

Imi = Iz = U _mi / R _m GI.1

is determined and then from the predetermined total voltage U _c and the measured voltage (U _m ) on the measuring resistor (R _m ) the measuring cell voltage (U _zi ) after

U _zi = U _c - U _mi GI.2

where U _c = 0 or ≠ 0,

is determined and then the electric field strength (E _zi ) after

E _2i = U _zi / d Eq. 3

where (U _zi ) the cell voltage at the time (tj) and (d) is the distance of the electrode surfaces (A ₁ , A ₂ ),

finally, it is determined as a liquid parameter average mobility of ions μ _: on a relation

μ, = d / (t, ^* E _zl ) Eq. 4

where (tj) is the clock time from i = 1 to n,

and / or for determining the mean ion concentration n, as a further liquid parameter, first the electrical conductivity (σ _a , _zi ) according to the relationship

σ _a , ₂ , = (1 _m , / A _m ) / (U _z , / d) Eq. 5

where (A _m ) is the average electrode area A _m = (A ₁ + A ₂ ) / 2, e is the elementary charge and (l _mi ) is the measurement current at the time (tj),

is determined and based on the average mobility of the ions μ, the mean ion concentration n; after the relationship

n _d , = σ _zι / (e * μ _dl ) Eq. 6

where i = 1 to n,

is determined and / or as a further liquid parameter on the basis of the mean ion concentration n; the pH after the relationship

pH * - Ig [In, (t,) l / (6.02214 ^* 10 ²³ )] Eq. 7

where In, (tj) l is the mean ion concentration at time (tj) dimensionless and in cm ^"3 and size 6,02214 * 10 ^{23 is} the avogadro constant,

is determined.

2. The method according to claim 1, characterized in that at (U _c ) = 0 alone by a primary voltage (U _e ) of the measuring cell (M _z ) a current flow (l _z ) is caused.

3. The method of claim 1 or 2, characterized in that the measuring current (l _mi) by means of an in series with the measuring cell (M _z) switched digital ammeter (DA), (with a digital current-voltage converter or with the external sensing resistor R _m ) and connected in parallel digital voltmeter (DV) or instead, with the help of an oscilloscope or recorder or voltage converter, wherein when using the external measuring resistor (R _m ) whose size represents the average internal resistance of the measuring cell (M ₂ ).

4. The method according to any one of claims 1 to 3, characterized in that at constant total voltage (U _c ) different from zero this periodically, alternately, ie as (+ U _C ) and (-U _c ) with the same or different duration .DELTA.t with or without a short circuit of the measuring cell (M _z ) during a dead time or without a dead time applied and provided by a Polwender.

5. The method according to any one of claims 1 to 4, characterized in that the

Total voltage (U ₀ ) is applied as a constant alternating voltage with a constant or variable frequency.

6. The method according to any one of claims 1 to 5, characterized in that temporally variable voltages or voltage pulses with the amplitude (± U _C) ) arbitrary pulse shapes and / or frequencies are applied.

7. The method according to any one of claims 1 to 6, characterized in that as the intervals .DELTA.t the cycle times (t,) constant or freely selectable values are applied.

8. Arrangement for determining liquid parameters by the method according to claims 1 to 7 consisting of

a measuring chamber (M _k) for receiving the liquid to be measured (S _x), which is arranged with a in the measuring chamber (M _k) measuring cell (M _z) (with at least two at the same distance (d) from one another arranged electrodes E _1, E ₂ ) with the conductive surfaces (A ₁ , A ₂ ) and a temperature sensor (T ₈ ), - An electrical module connected to the measuring cell (M _z ) which supplies the measuring cell (M _z ) with a total electrical voltage (U _c ) which may be zero or different from zero, comprising a switch (S _ae ) and a switch ( S _ec ) or only one switch (S _a , _e ) and has means for measuring the current passed through the measuring cell (M ₂ ) electric current (l _m ) = (l _z ), wherein

the measuring chamber (M _k), the voltage source (U _c), the switch (S _{a, e)} and (S _{e, c),} the temperature sensor (T _8), the means for measuring the electric current (l _m) interfaced are connected to an evaluation unit with a computer program and a display for the acquisition and storage of all acquired data and for the calculation and display of the parameters of the liquid.

9. Arrangement according to claim 8, characterized in that as means for measuring the current (l _m ) a sensitive ammeter, a measuring resistor (R _m ), a for detecting the voltage drop across the measuring resistor (R _m ), connected digital voltmeter (DV) , an oscilloscope, a voltage current transformer or a recorder are provided.

10. Arrangement according to claim 8 or 9, characterized in that the surfaces (Ai, A ₂ ) of the electrodes (E ₁ , E ₂ ) are flat or curved and preferably formed as plates of the same or different geometric shape, as a half-cylinder or as a cylinder and the size of the electrode surfaces (A ₁ = A ₂ ) or (A ₁ ) is not equal to (A ₂ ) and the electrodes (E ₁ , E ₂ ) have a similar or different material properties and / or coated with similar or different materials.

11. An arrangement according to one of claims 8 to 10, characterized in that up to the mutually positioned conductive electrode surfaces (A _1, A ₂₎ all other surfaces of the electrodes (Ei, E ₂₎ is isolated or the electrodes (E _1, E ₂ ) are formed completely isolated with the electrode surfaces (Ai, A ₂ ).

12. Arrangement according to one of claims 8 to 11, characterized in that the measuring chamber (M _k ) is directly or indirectly heated or cooled.

13. Arrangement according to one of claims 8 to 12, characterized in that the electronic module is equipped with software for calculating, storing and displaying the liquid parameters.

14. Arrangement according to one of claims 8 to 13, characterized in that (R _m ) has a value to 10 ⁹ Ω.

15. Arrangement according to one of claims 8 to 14, characterized in that individual components or connecting elements or the entire arrangement are shielded against electromagnetic influences.

16. Use of the arrangement according to claims 8 to 15 for the determination, control and monitoring of the parameters of liquids, preferably in combustion or electric motors and / or in technological processes and / or in hydraulic systems and / or in medical technology and / or in wind turbines and / or in supply lines and / or in titration technology and / or in laboratory and field measurement technology.

17. Use of the arrangement according to claim 16, that for controlling and monitoring the parameters of liquids, the arrangement is designed 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.