If I didn't think this had a good chance of being successful I wouldn't attempt. In an effort to fine tune the WM Smartline + weather monitor ET based watering system that I have I'm adding a Baseline Watertec S100 to it. http://www.baselinesystems.com/s100.html Now the limitation that the WM SL has is that it does not accurately measure rainfall. It is a traditional wafer type sensor. An upgrade to a tipping rain gauge would not improve this much since a tipping raingauge isn't going to measure a 2" rain in 30 minutes any different that a 2" rain over 6 hours. A more accurate assessment of watering needs can be made by an accurate and properly installed soil monitor is the basic hypothesis to all this. To set this all up I upgraded my WM SL panel to the latest version. This allows me to set the ET monitor rain delay manually. I adjusted my monitor rain sensor to 1/8" which is the most moisture sensitive setting. I zeroed out any rain delay so basically when it drys out watering can resume. Now on the Smartline is a second sensor port for break in the common type sensors. WM tells me it is okay to still use this port and it will also shut down the system. When the system has been shut down by this sensor port the ET data will still continue to accumulate. The ET data is only cleared by rain or manually clearing. The auto adjust setting will not override the secondary sensor unless put on sensor bypass. Anyway I'm not going to describe all the install details but want to mention that one sensor is being used for the whole system. Where Henry is standing is where it was installed. I chose this spot because it drains well, watered by MP rotators, gets dry just a tad faster than the rest of the yard, and the valve isn't too far away. Right now the sensor is going through a 24 hour threshold calibration.