Non-contact liquid level sensors use electromagnetic signals to measure and monitor levels in a container. A signal emitted from the sensor bounces off the surface of a liquid and travels back to the device. The time interval is used to calculate and display a level measurement. These continuous sensors measure the rising and falling liquid levels within a setpoint range but they are not immersed in the liquid. They mount outside of or onto the bung port of a container or tank. These sensors are suited for monitoring corrosive liquids, wastewater, and bulk storage containers.