An Ultrasonic BTU Meter is a device used to measure the heat energy consumption in heating or cooling systems. This consists of two ultrasonic flow sensors that are installed in the supply and return pipes of the heating or cooling system. It is particularly useful for monitoring and billing purposes in residential, commercial, and industrial applications. Furthermore, the Ultrasonic BTU Meter is widely used in district heating and cooling systems, as well as in various applications where precise measurement of energy consumption is necessary for billing, efficiency analysis, and system optimization.