1. A method of characterizing a process module having a plurality of process inputs that affect a process condition, using a process condition measuring device having a plurality of sensors that measure the process condition, comprising: placing the process condition measuring device in the process module; providing a first excitation to at least a first process input and providing a second excitation to at least a second process input, while recording the output of the plurality of sensors; and using the recorded output of the plurality of sensors to develop a model of relationships between the process condition and the plurality of process inputs, including a first relationship between the process condition at a first sensor and the first process input and a second relationship between the process condition at the first sensor and the second process input.