Question 59General Subjects - Assistant Engineer

The correct answer is D) Thermocouple pyrometer. A thermocouple pyrometer is the most suitable temperature transmitter for measuring diesel engine exhaust and boiler stack temperatures because it generates its own electromotive force (EMF) based on the temperature difference between the measurement point and a reference junction. This makes it well-suited for high-temperature applications like engine exhaust and boiler stacks. The other options are not as suitable - thermistors and resistance temperature detectors (RTDs) require an external power source, while radiation pyrometers measure the infrared radiation emitted by the target, which may not be as accurate for these specific applications.