Novel pressure stable thermoelectric flow sensor in non-steady state operation mode for inline process analysis in micro reactors

In this contribution results of the non-steady state operation of a novel pressure stable thermoelectric flow sensor chip for the inline chemical process analysis in micro reactors are presented. The sensor chip consists of a heater in between two thermopiles on a novel perforated membrane, thus liquid flows on both sides. Compared to the conventional constant overtemperature/current operation the heater is now operated in non-steady state/pulsed mode and step responses of both thermopiles are evaluated. Based on our results the non-steady operation of the heater leads to a better discrimination between thermal conductivity and heat capacity of the liquid.