What does a thermocouple primarily indicate in a metal heating setup?

• A. The velocity of gas flow
• B. The chemical composition of the metal
• C. The temperature of the metal to which it is attached
• D. The pressure in the system

Answer: (C)

In a metal heating setup, a thermocouple acts as a temperature sensor that measures the metal’s temperature at the point where it’s attached. It works by producing a small voltage that changes with temperature, which a controller or readout converts into a temperature value. This makes it a direct indicator of how hot the metal itself is, which is what you rely on to control heating, prevent damage, and ensure consistent material properties.

It doesn’t measure how fast gas is flowing, the metal’s chemical makeup, or the system’s pressure. Those require other kinds of tools—flow meters or anemometers for velocity, spectroscopy or chemical tests for composition, and pressure gauges for pressure.