A device that converts a physical quantity into a measurable electrical signal is known as what?

A device that converts a physical quantity into a measurable electrical signal is referred to as a transducer. Transducers are essential components in instrumentation and control systems, as they allow for the measurement and monitoring of various physical parameters, such as temperature, pressure, flow, and level.

The primary function of a transducer is to take a physical input (like pressure, temperature, light, etc.) and transform it into an electrical signal that can be easily measured, recorded, or manipulated by electronic systems. This conversion is crucial in a wide range of applications, enabling accurate data collection and response in various industries.

While sensors also play a critical role in detecting and responding to physical phenomena, they do not necessarily imply the conversion into an electrical signal; they may only respond to physical changes. A transmitter is typically used to send the signal over distances and often involves additional processing of the signal. A converter generally refers to devices that change one form of signal into another but may not specifically relate to the direct conversion of physical properties to electrical signals. Therefore, transducers uniquely meet the criteria established in the question.