A detection system is presented. The detection system includes a sensing component and a data analyzer. The sensing component includes a first sensor and a second sensor in fluid communication with the first sensor. The first sensor is disposed to allow operation at a predetermined temperature T.sub.1 and is selective to a first gas species at T.sub.1 and in presence of a second gas species. The second sensor is disposed to allow operation at a temperature T.sub.2 and is sensitive to the first gas species and a second gas species at T.sub.2. Temperature T.sub.2 is lower than T.sub.1. The data analyzer is disposed to receive an output signal from the sensing component and configured to calculate concentrations of the first gas species and the second gas species based on the output signal from the sensing component. A method of calculating concentrations of gas species in a gaseous mixture is also presented.