Gas Concentration and Flow Speed Measurement by Thermal Excitation using one Single Chip

In this contribution, a novel approach is presented to measure simultaneously gas concentration and flow speed of binary gas mixtures. This multi parameter detection is achieved by a thermal flow sensor using two different time independent excitation modes. Gas concentration is obtained by power mode; afterwards flow speed is measured by temperature excitation. The combination of these two principles improves the accuracy and sensitivity. One possible application of this measurement technique might be in biogas plant in order to control the fermentation process and calculate the gas’ fuel value.