Design of a neutrally buoyant self-powered multi-parameter sensor for data logging in flow applications

Experimental acquisition of spatially distributed parameters in large scale vessels and containers is of great interest for investigation and optimization of plants and processes such as stirred tanks, chemical reactors or bioreactors. For the measurement of process parameters in a stirred fermentation biogas reactor we developed the concept of neutrally buoyant self-powered sensor particles. The prototype sensor performs logging of temperature, absolute pressure and 3D-acceleration data and is integrated in a robust capsule which gives a balance between buoyancy and gravitation with respect to the liquid process substrate. In an initial test of the developed prototype its autonomous operation has been successfully proved showing feasibility for future application in a biogas reactor.