Accuracy and consistency for level measurements is of great importance to different industries. Level measurements are taken and used for both processes and storage tanks for inventory and control. The reliable measurement and reporting of fluid level is often critical to a process efficiency and safety of a storage tank. The end of measurement range or the bottom of the tank receives special attention to reliably detect the emptiness or nearly emptiness of a product in a storage tank.
For non-contact level measurement methods employing time of flight methods, such as ultrasound, radar, and laser, the measurement extends nearly to the bottom of the tank with some margin defined by the manufacturer. Even then, the measurement is usually not possible or not reliable to the absolute bottom of the tank.