Which temperatures can resistance-type temperature indicators using Wheatstone bridge or ratiometer circuits measure?

Resistance-type temperature indicators that utilize Wheatstone bridge or ratiometer circuits are designed to measure a range of temperature types due to their sensitivity and accuracy in detecting changes in resistance caused by temperature. These indicators can be calibrated for various applications, allowing them to measure temperatures in free air, exhaust gas, carburetor air, engine coolant, and oil.

The reason option B is correct is that these systems can effectively track temperatures in diverse environments. For instance, they can measure the temperature of free air, providing data essential for atmospheric assessments. Similarly, they can monitor exhaust gas temperatures, which is crucial for effective engine performance evaluation and to prevent overheating. Carburetor air temperature is monitored to optimize fuel-air mixtures for better engine performance. Moreover, measuring coolant and oil temperatures is vital for engine health, ensuring that the engine operates within safe thermal limits.

The flexibility of resistance-type indicators allows multiple temperature measurements crucial for flight safety and engine performance, making B the most comprehensive choice.