A method is provided for measuring a concentration of dibasic acid in a substance in a gas cleaning process, the method comprising the steps of sending a plurality of voltage pulses through the substance by a first electrode and a second electrode, wherein the first and second electrodes are in contact with the substance, receiving current responses generated by the plurality of voltage pulses, and analyzing the current responses using a multivariate data analysis for calculation of the concentration of dibasic acid in the substance. Also provided is a dibasic acid sensor, control unit and analysing unit for performing such a method.
