Why do I get different readings If I take 2 measurements in the exact same spot using the same probe location??

Carmen -

It is impossible to measure the exact same spot with the POGO. Once you measure a spot, you create voids in the turf. Another sensor in the same spot is not compressed against the turf or soil exactly the same way and that impacts the reading. If you move the sensor right next to that spot, there may be slightly more or less organic matter, microbial activity, roots, or something slightly different that affects the actual moisture content. We measure the moisture content and EC in that zone so precisely that any small change is picked up. It is always best to take an average set of representative samples across the zone. If you do that consistently with multiple devices, the average will be statistically close.