Dear @sylke
this is very kind of you.
i) Could you detail the 2 different sensors that you have been using with citizens throughout Hollandse Luchten? How do these sensors differ? Where can they be purchased?
ii) How have you been guiding citizens to use the sensors and make sense of the gathered data?
iii) How many sensors are needed to make for meaningful contrasted data? 
e.g. for a citizens use case like this that @robert.axelsson is in touch with.