Towards a wireless sensor system for real‐time H 2 O 2 monitoring in aseptic food processes

A wireless sensor system based on the industrial ZigBee standard for low‐rate wireless networking was developed that enables real‐time monitoring of gaseous H 2 O 2 during the package sterilization in aseptic food processes. The sensor system consists of a remote unit connected to a calorimetric gas sensor, which was already established in former works, and an external base unit connected to a laptop computer. The remote unit was built up by an XBee radio frequency (RF) module for data communication and a programmable system‐on‐chip controller to read out the sensor signal and process the sensor data, whereas the base unit is a second XBee RF module. For the rapid H 2 O 2 detection on various locations inside the package that has to be sterilized, a novel read‐out strategy of the calorimetric gas sensor was established, wherein the sensor response is measured within the short sterilization time and correlated with the present H 2 O 2 concentration. In an exemplary measurement application in an aseptic filling machinery, the suitability of the new, wireless sensor system was demonstrated, wherein the influence of the gas velocity on the H 2 O 2 distribution inside a package was determined and verified with microbiological tests.