This work describes the development and application of different lance-based monitoring systems coupled to an integrated multiparameter sensor probe for the spatial investigation of the liquid phase in biotechnological processes. Miniaturized electrochemical sensors are integrated into a housing, which is fixed at the head of a lance, both made of stainless steel. It can be moved inside a reactor in horizontal direction by the lance itself and in vertical direction by a flexible rope, which is connected to the sensor probe. Inserting the sensor unit directly into the liquid phase of a fermenter, e.g. in laminar processes like biogas and beer production, coupled with multiposition measurements allows to obtain space and time resolved data. The monitored parameters are the pH value, the redox potential, the temperature, and the concentration of dissolved carbon dioxide. Wireless data transfer is realized by means of radio technology with the virtual control center RAMOC (Radio Aided Monitoring) of the company innotas GmbH. Results of the real-time determination in the liquid phase in an industrial, continuously operated biogas plant during several weeks are presented as a case study.