THE INVENTION RELATES TO A MEASURING ARRANGEMENT FOR DETERMINING AT LEAST ONE PARAMETER OF A BLOOD SAMPLE, COMPRISING A FLOW-THROUGH MEASURING CELL (1), IN WHICH AT LEAST ONE LUMINESCENCE-OPTICAL SENSOR ELEMENT (ST, SO, SG) IS ARRANGED AND CAN BE BROUGHT INTO CONTACT WITH THE BLOOD SAMPLE, AT LEAST ONE LIGHT SOURCE (4) FOR EXCITING THE LUMINESCENCE-OPTICAL SENSOR ELEMENT AND AT LEAST ONE PHOTODETECTOR (6) FOR RECEIVING THE LUMINESCENCE RADIATION EMITTED BY THE LUMINESCENCE-OPTICAL SENSOR ELEMENT, THE LIGHT SOURCE (4) AND THE PHOTODETECTOR (6) BEING ARRANGED ON OPPOSITE SIDES (7) AND (8) OF THE FLOW-THROUGH MEASURING CELL (1). THE AT LEAST ONE LUMINESCENCE-OPTICAL SENSOR ELEMENT (ST, SO, SG) IS ARRANGED ON THE EXCITATION SIDE (7) OF THE FLOW-THROUGH MEASURING CELL (1), FACING THE LIGHT SOURCE (4), THE LIGHT SOURCE (4) EMITTING AN EXCITATION WAVELENGTH OF LESS THAN 600 NM, FOR EXAMPLE 425 NM, AND THE LUMINESCENCE RADIATION OF THE LUMINSCENCE-OPTICAL SENSOR ELEMENTS (ST, SO, SG) BEING IN A WAVELENGTH RANGE OF MORE THAN 600 NM, SO THAT THE EXCITATION RADIATION THROUGH THE BLOOD SAMPLE IS ABSORBED TO A GREATER EXTENT THAN THE LUMINESCENCE RADIATION. (FIG. 1)
