Method and devices for the calibration of a pump for the blood treatment

A method for determining an actual pump rate or for calibrating a blood pump of a blood treatment apparatus connected to an extracorporeal blood circuit, the method comprising:

• providing a blood pump of a blood treatment apparatus, or establishing a signal connection to a blood pump, the blood pump connected to comprising:
• at least a first fluid source;
• at least a first line of an extracorporeal blood circuit which is connected downstream to the first fluid source;
• and
• at least one reception unit for receiving fluid of the first fluid source, wherein the reception unit is in fluid communication with the first line,
• wherein the reception unit is arranged on or at a first weighing device such that a weight of at least one of the reception unit or of a content of the reception unit is determinable via the first weighing device;
• setting a value for a pump rate being adjustable at the blood pump as a set pump rate, or transmitting such a value to the blood pump as a set pump rate;
• operating the blood pump at the set pump rate during a conveyance time period such that the fluid from the first fluid source is conveyed as actual volume through the first line into the reception unit;
• determining via the first weighing device an actual volume conveyed during the conveyance time period based on a change of the weight of the reception unit or of the contents of the reception unit;
• and
• determining a mathematical relation between the actual volume and a target volume, the target volume resulting from the conveyance time period and the set pump rate;
• wherein the blood treatment apparatus is configured to maintain a particular pressure within the first line before the conveyance time period and to maintain the particular pressure within the first line after the conveyance time period.