Measuring device, and conductivity measuring device, for determining flow capacities of electroconductive liquids, measuring element, and method

1. A measuring device for determination of flow amounts, dV(z), of electrically conducting liquids having conductivity LF, for flow through a container in which the liquid level varies in the vertical direction (z-direction), which device is comprised of:

a container having: a bottom wall, a liquid inlet, and a liquid outlet; and

a conductivity measuring device comprised of the following components:

a voltage source;

an evaluation device; and

at least one measuring element, which measuring element:

is disposed in the container and is connected to the evaluation device; and

has at least two electrodes which extend in the z-direction, which electrodes are disposed a distance apart in a direction perpendicular to the z-direction, wherewith

Z max

represents a distance from a first end (lower end) of the electrode (at z=0) to a second end (upper end) of the electrode; wherein at time intervals t i −t i−1 (for i=1 . . . n), the conductivity measuring device delivers measurement values

M t i ( V )= M ( V ( z )) ˜LF·f M ( V ( z ))

wherein at least the container or the conductivity measuring device or a combination thereof is configured such that it is or they are describable by at least one parameter function dependent on V(z), f P I (V(z)) (for I=1 . . . m), so that the following applies:

f M ( V ( z ))˜ f ( f P I ( V ( z ) for I= 1 . . . m ))˜ b M V(z) ,

where b M is a number which is not equal to zero or 1;

wherein the evaluation device is configured at least so as to be able to deliver quotients of the measured values and to obtain logarithms of the quotients.

2. The measuring device according to claim 1 , wherein the parameter P I represents a configuration of the container, F, from which a fill volume is determined, wherewith F is expressed by:

F ( V ( z ))= f P I ( V ( z ))˜ b F V(z) .

3. The measuring device according to claim 1 , wherein the measuring element is integrated into a wall of the liquid container.

4. The measuring device according to claim 1 , wherein the liquid container comprises a feed funnel of a water filter device.

5. A conductivity measurement device for determination of flow amounts, dV(z), of electrically conducting liquids for situations in which the liquid level varies in the vertical direction (z-direction), which device is comprised of:

a voltage source;

an evaluation device; and

at least one measuring element, which measuring element:

is connected to the evaluation device; and

has at least two electrodes which extend in the z-direction, which electrodes are disposed a distance apart in a direction perpendicular to the z-direction, wherewith Z max

represents a distance from a first end (lower end) of the electrode (at z=0) to a second end (upper end) of the electrode; wherein at time intervals t i −t i−1 (for i=1 . . . n), the conductivity measuring device delivers measurement values

M t i ( V )= M ( V ( z ))˜ LF·f M ( V ( z ));

further in that the conductivity measuring device is configured such that it is describable by at least one parameter function dependent on V(z), f P I (V(z)) (for I=1 . . . m), so that the following applies:

f M ( V ( z ))˜ f ( f P I ( V ( z ) for I= 1 . . . m )˜ b M V(z)

where b M is a number which is not equal to zero or 1;

and in that the evaluation device is configured at least so as to be able to deliver quotients of the measured values and to obtain logarithms of the quotients.

6. The device according to claim 1 , wherein for at least one parameter function the following applies:

f P I (V(z))˜b P I V(z) , wherewith preferably 0<b P I ≦5, and b P I ≠1, and wherewith z is expressed in centimeters.

7. The device according to claim 6 , wherein at least one parameter P I is selected such that f P I (V(z))˜b P I V(z) , wherewith preferably 1<b P I ≦1.5 and wherewith z is expressed in centimeters.

8. The device according to claim 1 , wherein the parameter P I is an area A of at least one of the electrodes; and in that the area A is expressed as follows:

A ( V ( z ))= f P I ( V ( z ))˜ b A I V(z) .

9. The device according to claim 1 , wherein the parameter P I is the distance D between the electrodes; and in that the distance D is expressed as follows:

D ( V ( z ))= f P I ( V ( z ))˜ b D −V(z) .

10. The device according to claim 1 , wherein the measuring element has a support element; and in that the two electrodes are disposed on opposite sides or faces of the support element.

11. The device according to claim 1 , wherein the measuring element is disposed in the liquid container in such a manner that the broad second end of the electrode is disposed at the top.

12. The device according to claim 1 , wherein the evaluation device is connected to a display unit.

13. The device according to claim 1 , wherein at least the voltage source, the evaluation device, and at least one measuring element are integrated into a single module or subassembly.

14. The device according to claim 13 , wherein the display unit is integrated into the module or subassembly.

15. The device according to claim 1 , wherein at least one element is disposed between the two electrodes, which element changes a path length of electric field lines which form between the two electrodes.

16. The device according to claim 15 , wherein said element is configured such that the path lengths of the electric field lines decrease exponentially with increasing value of z.

17. The device according to claim 15 , wherein said element is a plate having a curved free forward edge.

18. The device according to claim 17 , wherein the two electrodes are disposed side by side on a support element, and in that the plate is disposed between the two electrodes.

19. The device according to claim 15 , wherein the two electrodes are disposed on opposite sides or faces of a support element, and in that each electrode has a respective plate disposed laterally of and close to it.

20. The device according to claim 18 , wherein the plate is disposed perpendicularly to the support element.

21. The device according to claim 1 wherein the device is a volumetric load measuring device for filter cartridges.

22. The device according to claim 21 , wherein the measuring device has a display unit which indicates when the filter cartridge is due to be replaced.

23. A method of determining the overall amount of flow, dV, of electrically conducting liquids of conductivity LF, through a container in which the liquid level varies in the vertical direction (z-direction), which method employs a container and device for measuring conductivity; comprising the following steps:

configuring at least the container or the conductivity measuring device or a combination thereof such that it is or they are describable by at least one parameter function dependent on V(z), f P I (V(z)) (for I=1 . . . m);

devising or adapting the at least one parameter function, f P I (V(z)), such that for the measurement values delivered by the conductivity measuring device:

M(V(z))˜LF·f M (V(z))˜f(f P I (V(z)))˜b M V(z) ;

carrying out a measurement to determine the basis, b M ;

determining measured values M t i (V(z)) at time intervals t i −t i−1 (for i=1 . . . n);

determining quotients M t i+1 /M t i , and determining the logarithms of such quotients, in order to determine dV i ; and

adding together the n-fold values dV i , to determine the overall amount, dV, which has flowed through.

24. The method according to claim 23 , wherein the measurement values M t i , are determined at time intervals in the range of 1 to 100 seconds.

25. The method according to claim 23 , wherein the measurement values M t i are determined at time intervals in the range of 1 to 20 sec.