Which instrument measures the temperature of the feedwater entering the boiler?

The instrument that measures the temperature of the feedwater entering the boiler is the feedwater temperature gauge. This gauge is specifically designed to provide real-time data on the temperature of the feedwater, which is crucial for efficient boiler operation. Measuring the feedwater temperature helps in optimizing the thermal efficiency of the boiler and ensures that the water entering the boiler is at the appropriate temperature for effective steam generation. By accurately monitoring the feedwater temperature, operators can make informed adjustments to the boiler controls and system operations to achieve desired performance levels and avoid issues such as thermal shock or inefficient combustion.

Other instruments, like the pressure regulator, feedwater pump, and main steam stop, serve different functions in the boiler system, such as controlling pressure, moving water into the boiler, or isolating steam flow, respectively. Therefore, they do not measure the feedwater temperature and are not suited for this specific function.