A level transmitter is a device used in industrial applications to measure and transmit information about the level of a substance (such as liquid or solid material) in a tank or vessel. It employs various technologies, including ultrasonic, radar, capacitance, or pressure sensors, to accurately gauge the height of the substance. The transmitter then converts this measurement into a standardized signal, typically a 4-20 mA current or digital signal, which can be easily interpreted by control systems. This information is crucial for monitoring and controlling processes in industries such as manufacturing, petrochemicals, and water treatment, ensuring efficient and safe operations.