Passes a spark to any conductor when touched by an element The element is determined by the ctype of the sensor. With the new Prop tool it'll be really easy to change it. Uses incude polution sensor for engines, No walls in reactors since one could just set the ctype to WTRV, also the reactor will not loose water, because there are no gas walls for water to get deleted in. Im sure many other uses are out there

Well the detector wall passes spark when any particle goes into it. Even with filtering with liquid\solids\gas walls it will still accept any particle. Sensor will only pass a spark when touched by a particle specified with Sensor's ctype. Ex lets say you want to monitor un-burnt oil from an engine. Set the ctype of Sensor to oil. then if oil is present it will spark. It will not spark when in contact with anyother material