What type of temperature measurement is generally considered more accurate for assessing hot spots on vessels?

Thermocouples are considered more accurate for assessing hot spots on vessels due to their ability to provide precise temperature readings by directly measuring the temperature of the surface to which they are attached. They work based on the thermoelectric effect, allowing for quick response times and reliable readings in varied temperature ranges. This direct contact with the vessel surface ensures that the temperatures captured reflect actual conditions, especially in areas where overheating may occur.

Unlike hand measurements, which can be subjective and unreliable, thermocouples deliver consistent and reproducible data. Infrared thermometers, while useful for non-contact measurements, can be influenced by surface emissivity and may not accurately reflect the temperature of the surface if not used correctly. Digital readouts, often associated with other measurement devices, do not themselves measure temperature but provide a representation of data collected from sensors. Thus, thermocouples are a preferred choice in industrial settings where precise monitoring of hot spots is crucial for ensuring safety and operational integrity.