How do fuel flow transmitters primarily transmit data?

Fuel flow transmitters primarily transmit data electrically, which is the basis for the correct answer. These devices use electrical signals to measure and report the flow of fuel within the system. When fuel passes through the transmitter, it interacts with a sensing element that generates an electrical signal proportional to the flow rate. This signal is then transmitted to the aircraft's engine control unit or instrumentation system for monitoring and analysis.

The advantage of using electrical signals is that they can be easily integrated with other electronic systems within the aircraft. This allows for precise measurement and quick response times, crucial for efficient engine performance and fuel management. Additionally, electrical transmission of data allows for greater accuracy and reliability, especially in harsh operating environments like those encountered in aviation.

Other methods, such as mechanical transmission, would involve moving parts that are more prone to wear and failure, while optical methods are less common in fuel flow measurement due to practical challenges in application. Pressure change transmission may be useful in certain contexts, but it is not the primary method used in modern fuel flow transmitters, as electrical methods provide a better combination of accuracy, speed, and reliability.