For his senior project, Allen Lu (NYU Tandon, IDM ’19) built a prototype for a flood water sensor that can be deployed to track the frequency and depth of street-level flooding. Details are provided on his Instructables post:
“The main component in this project is called the eTape Liquid Level Sensor, which has a range from 0-12″. It’s commonly used for measuring the depth of liquid substances – in this case, it will be used to measure flood depth. Since this is an analog resistive sensor, the value of resistance that it outputs will change based on the water depth. This is how we’ll know whether it’s flooding. For example, with no water at 0″, my sensor outputs 2248 Ω. At 12″, it outputs 490 Ω. Of course, these values will differ slightly for each sensor, but in general it is an inverse relationship: as flood depth increases, resistance decreases, and vice versa. So, if we know the resistance is 1450 Ω, we can say the water depth is around 6″. The only way to find your sensor’s depth vs. resistance relationship is through testing.”
