The invention relates to a device for measuring at least one parameter of an arterial blood sample, comprising a flow sensor (2) having standardized connecting elements (3, 4) which are connected to the inlet and the outlet side (5, 6) of the measuring cell (7) of the flow sensor (2), said measuring cell (7) having at least one optochemical sensor element (8) which can be brought in contact with the blood sample. A connector (9) is removably placed on the flow sensor (2) and comprises at least one light source (10) for exciting the optochemical sensor element (8) and at least one photodetector (11) for receiving the measurement radiation of the optochemical sensor element (8). An electronic module (12) has an electric connecting line (13) to the connector (9) and contacts the at least one light source (10) and the at least one photodetector (11), the flow sensor (2) being connectible to the standardized connection (14) of an arterial catheter (1) via the connecting element (3) on the inlet side and to the standardized connection (15) of an arterial infusion set (16) via the connection (4) on the outlet side.
