I was thinking about what sensors i could use to monitor my generator. a coolant temp sensor could be used to monitor my water temps. and a differential Pressure Feedback EGR sensor could be calibrated to monitor flow. those of you not familiar a DPFE is a sensor used br ford to monitor the flow of EGR. it has a metal tube with a tube with a larger tube diameter and a smaller tube diameter attached perpendicular to the flow tube. it can monitor flow by measuring the difference in pressure between the small and large tubes, hence the name. it must be caliabrated but it could be used to make sure you are getting the flow rate you want and make sure that it stays that rate over a long period of time.