Method for quality monitoring and detecting the contamination of a space, wherein the space is a volume which can be determined by spatial coordinates and which comprises a fluid or which is substantially filled with a fluid, comprising the method steps: a) measuring a plurality of quality parameter actual values in a space by use of a sensor system, wherein the space is a volume which can be determined by spatial coordinates and which comprises a fluid or which is substantially filled with a fluid, wherein the actual value of at least one quality parameter is measured at a plurality of measurement locations, wherein the sensor system comprises a plurality of sensors, wherein the sensors are mobile sensors, or at least one sensor is a stationary sensor and at least one sensor is a mobile sensor, wherein each sensor measures the at least one actual quality parameter value at a position of the measurement location determined by means of spatial coordinates; b) transmitting the quality parameter actual values measured at a plurality of measurement locations to a data processing system; c) matching the quality parameter actual values measured at the respective measurement locations with target values stored in the data processing system for the respective measurement locations, d) moving the at least one mobile sensor by means of a control system to a measurement location spaced apart from the previous measurement location of the at least one mobile sensor, wherein the at least one mobile sensor approaches different measurement locations according to a movement plan stored in the data processing system, characterized in that in the event of a malfunction in which at least one actual value deviates from the target value defined for the respective measurement location, at least one mobile sensor is moved by the control system in a manner deviating from the stored movement plan and measures in the space around the position of the measurement location with the detected actual value deviation additional quality parameter actual values at additional measurement locations and transmits them to the data processing system, wherein the data processing system determines the spatial spread, type of contamination and/or concentration of the respective contamination of the space. a) measuring a plurality of quality parameter actual values in a space by use of a sensor system, wherein the space is a volume which can be determined by spatial coordinates and which comprises a fluid or which is substantially filled with a fluid, wherein the actual value of at least one quality parameter is measured at a plurality of measurement locations, wherein the sensor system comprises a plurality of sensors, wherein the sensors are mobile sensors, or at least one sensor is a stationary sensor and at least one sensor is a mobile sensor, wherein each sensor measures the at least one actual quality parameter value at a position of the measurement location determined by means of spatial coordinates; b) transmitting the quality parameter actual values measured at a plurality of measurement locations to a data processing system; c) matching the quality parameter actual values measured at the respective measurement locations with target values stored in the data processing system for the respective measurement locations, d) moving the at least one mobile sensor by means of a control system to a measurement location spaced apart from the previous measurement location of the at least one mobile sensor, wherein the at least one mobile sensor approaches different measurement locations according to a movement plan stored in the data processing system,