What is an indirect reading device that changes the fluid level to an electronic signal?

The correct choice refers to a device specifically designed to measure the level of fluid in a tank and convert this measurement into an electronic signal. A tank level indicator, as described, typically utilizes sensors that respond to changes in fluid level—such as ultrasonic, capacitive, or pressure-based sensors—to provide real-time data. This data is then transformed into an electronic signal that can be displayed on monitoring systems or integrated into process control systems.

This capability is essential in various applications, from industrial processes to wastewater management, where knowing the exact fluid level is critical for safety, efficiency, and preventing overflow. The use of electronic signals also allows for better integration with automated systems, enabling advanced monitoring and control capabilities.

The other choices represent devices with different functions: a pressure gauge measures the pressure within a system rather than fluid level; a digital flow meter measures the rate of flow rather than the level; and a flow switch is designed to detect the presence or absence of flow rather than quantify fluid levels directly.