After having done several runs for Hoogheemraadschap Delfland with the usual array of DO, EC, Ph and temp sensors we agreed to have a test with a dedicated nitrogen sensor. Normally, we would infer nitrogen values based on the combination of EC and DO, but in this case we knew that in certain cases water gets polluted with fertilized that cause an enormous rise in NO3, while hardly affecting EC and DO. So we took the latest in NO3 real-time sensing from In-Situ and mounted it on the Aquatroll 600, adding it to one of the Platypus drones. We left the normal sensor array, mainly from Atlas Scientific, in place in order to have a comparison.
In general we were very happy with the results. The values are very close to what we expected, and the user-friendlyness of the Aquatroll is very good. The only drawback was the sensor sticking out quite a bit, which increased the minimum depth we needed to operate to about 20 centimeters. Still quite impressive, but in The Netherlands dry season this year that worked only just in the small ditches between the greenhouses. Still, a big success and this will most likely be part of the standard service in the future.