WSSFC-ULC is a Sigfox-Ready Ultrasonic Level Sensor to measure the level of liquid surface of water, oil... This level sensor utilizes ultrasonic technology to measure the surface of liquid, the principle is to measure the time of flight of the ultrasound pulse in the air environment. The ultrasound pulse will be ejected from ultrasonic transducer, go thru the air and reaching the surface of liquid, then reflected back to the ultrasonic transducer, the measuring circuit will measure the time of flight of the Pulse then calculate the distance from transducer to the surface. With ultra-low power design and smart firmware allow the sensor can last up to 10 years with 02 x AA-type batteries (depends on configuration). WSSFC-ULC can support all regions of Sigfox network in over the world.