A sensor assembly for bio-analytic measurements in body fluids, the sensor assembly comprising: - a measurement chamber extending in an axial direction from an inlet to an outlet the measurement chamber having a transverse cross-section with side walls defining a chamber width in a horizontal direction, and with top and bottom walls defining a chamber height in a vertical direction, each of the side walls, top wall and bottom wall having a respective wall wettability for aqueous solutions; - a first sensor (10a-h) adapted to measure a first parameter of body fluids, the first sensor having a first sensor surface (11a-h) exposed to the inside of the measurement chamber at a first axial position, the first sensor surface having a first wettability for aqueous solutions; characterized in that the sensor assembly further comprises: - a second sensor adapted to measure a second parameter of body fluids, the second sensor having a second sensor surface exposed to the inside of the measurement chamber at a second axial position upstream or downstream from the first axial position, the second sensor surface having a second wettability for aqueous solutions higher than the first wettability, wherein the second sensor surface and the measurement chamber at the second axial position are dimensioned such that the width of the measurement chamber is larger than the width of the sensor, and wherein the top and bottom walls are plane parallel and separated from each other by a spacer gasket (B) with a through-going recess defining a contour of the measurement chamber as seen in a vertical projection, wherein the spacer gasket has a thickness determining the chamber height. - a measurement chamber extending in an axial direction from an inlet to an outlet the measurement chamber having a transverse cross-section with side walls defining a chamber width in a horizontal direction, and with top and bottom walls defining a chamber height in a vertical direction, each of the side walls, top wall and bottom wall having a respective wall wettability for aqueous solutions; - a first sensor (10a-h) adapted to measure a first parameter of body fluids, the first sensor having a first sensor surface (11a-h) exposed to the inside of the measurement chamber at a first axial position, the first sensor surface having a first wettability for aqueous solutions; characterized in that the sensor assembly further comprises: - a second sensor adapted to measure a second parameter of body fluids, the second sensor having a second sensor surface exposed to the inside of the measurement chamber at a second axial position upstream or downstream from the first axial position, the second sensor surface having a second wettability for aqueous solutions higher than the first wettability, wherein the second sensor surface and the measurement chamber at the second axial position are dimensioned such that the width of the measurement chamber is larger than the width of the sensor, and wherein the top and bottom walls are plane parallel and separated from each other by a spacer gasket (B) with a through-going recess defining a contour of the measurement chamber as seen in a vertical projection, wherein the spacer gasket has a thickness determining the chamber height. <EOS>