[Mike] lives in a temperate rainforest in Alaska (we figured from his website’s name) and uses a 570 gallon oil tank to ... the oil level and finally opted for an ultrasonic sensor.

[Renzo Mischianti]’s friend has to keep a water tank topped up ... with a solar-powered sensor that communicates over LoRa, and a controller that receives the water level readings and powers ...

These sensors are used for tank level measurement ... These durable ultrasonic sensors also play a vital environmental role in water monitoring for irrigation, flood, tsunami, and sea level ...