D1CS-D Capacitive Water Tank Level Sensor Come with 500mm Cable(Pack of 3)

Los use para controlar una válvula solenoide de entrada de agua a un tanque de 300l de apartamento, y para detectar tanque vacío y apagar la bomba de agua. Debido a que funcionan con 5V , use un circuito de 2 relés que venden en Amazon para Arduino y trabajan bien, a través de la pared del tanque de 4mm de espesor.

They are nice and compact. Unfortunately since you can't calibrate these, you might find that they come on / remain off when they shouldn't, and this behavior can change day to day. I ended up having to replace them with a homemade one so I'd have more control.

The data sheet that came with these sensors was terrible, so I made my own for others to use. I tested these sensors to measure: Current draw, sensing distance, and general operability. They sense water level well (doesn't matter if the liquid is conductive or not, I did the experiment and nothing changes). You must put the smooth side towards the liquid to be sensed, or they won't work. This is odd, as the mounting flanges seem backwards at first glance. You will see for yourself. I initially thought they didn't work. There are errors in the data sheet supplied by the manufacturer, but my numbers are correct for the three units I tested. Overall, not a bad deal especially for something so cheap. I wouldn't use it for Grandma's meds, but that goes without saying...