The present application is directed to a multi-sensor gas sampling detection system and method for detecting and measuring the radicals in a radical gas stream and includes at least one radical gas generator in communication with at least one gas source. The radical gas generator may be configured to generate at least one radical gas stream which may be used within a processing chamber. As such, the processing chamber is in fluid communication with the radical gas generator. At least one analysis circuit in fluid communication with the radical gas generator may be used in the detection and measurement system. The analysis may be configured to receive a defined volume and/or flow rate of the radical gas stream. In one embodiment, the analysis circuit may be configured to react at least one reagent with radicals within the defined volume of the radical gas stream thereby forming at least one chemical species within at least one compound stream. At least one sensor module within the analysis circuit may be configured to measure a concentration of the chemical species within the compound stream. One or more flow measurement modules may be in fluid communication with the sensor module. During use, the flow measurement module may be configured to measure the volume of at least one of the compound stream and radical gas stream.