I am thinking to develop a remote-sensing applications for vehicle pollutions. In such cases generally expensive optical IR and UV sensors are used because more precise.
On the contrary gas sensors are cheaper but much less precise. Generally these sensors have a response time from 30 to 60 seconds.
Suppose I can use a less precise estimate: can environmental polluting gas sensors detect emissions of a low speed passing vehicle in a semi-closed environment such as a garage to have an approximate estimation?
My biggest fear is that these sensors are too slow to detect anything, even for a low-speed vehicle in load conditions.