Balancing device, dialysis machine, extracorporeal circulation and method for balancing fluids with a fluid measuring cell

21:

• The balancing device according to claim 20, wherein the differential flow measuring unit is a differential flow sensor for direct measurement of the differential flow between the flow in the first flow path and the flow in the second flow path without a separate measurement of flow in the first flow path or a separate measurement of the flow in the second flow path.

22:

• The balancing device according to claim 21, wherein the differential flow sensor has a first flow measuring cell in first flow path and a second flow measuring cell in the second flow path, the flow passing through the second flow measuring cell in countercurrent with the first flow measuring cell,

23:

• The balancing device according to claim 20, wherein the differential flow measuring unit comprises a first flow sensor for measuring flow in the first flow path and a second flow sensor for measuring flow in the second flow path.

24:

• The balancing device according to claim 23, wherein at least one of the first and second flow sensors is a flow measuring cell selected from the group consisting of a volume flow sensor and a mass flow sensor,

25:

• The balancing device according to claim 20, wherein the additional flow path has a cutoff valve.

26:

• The balancing device according to claim 20, wherein the predetermined condition is satisfied when the differential flow is approximately zero.

27:

• The balancing device according to claim 20, wherein the differential flow is determined as a flow rate or as a flow volume.

28:

• The balancing device according to claim 20, partially or completely embodied as a disposable article or as part of a disposable article.

29:

• The balancing device according to claim 20, wherein the differential flow is measured as a differential volume, as an integral of a differential flow or as a difference between an integral of flow in the first flow path and an integral of flow in the second flow path.

30:

• A dialysis machine comprising a balancing device according to claim 20 for balancing dialysis fluid.

31:

• An extracorporeal blood treatment unit having a blood path and a dialysis fluid path containing a balancing device according to claim I for balancing dialysis fluid in the dialysis fluid path.

33:

• The method according to claim 32, wherein the predetermined condition is met when the differential flow is approximately zero.