WSLRW-RULA is a LoRaWAN ultrasonic level sensor to measure the water surface level in the small tanks. This level sensor uses ultrasonic technology to measure the solid surface of waste, the principle is to measure the time of flight of the ultrasound pulse in the air environment. The ultrasound pulse will be ejected from the ultrasonic transducer, go thru the air and reach the solid surface of the waste, then be reflected on the ultrasonic transducer, the measuring circuit will measure the flight time of the pulse and then calculate the distance from the transducer to the surface. The ultra-low power design and smart firmware allow the sensor to last up to 5 years with just 2 x AA batteries (depending on configuration). The sensor will transmit data over kilo-meters to the LoRaWAN gateway, any brand on the market. The level sensors are most widely applied in Water & Wastewater Management, Industrial Manufacturing, Agriculture & Irrigation, Food & Beverage and Residential & Smart Homes.