Measuring temperature with a thermocouple isn’t always as simple as attaching a sensor and reading the value. One of the most common sources of confusion—and error—is the difference between surface temperature and internal (process) temperature. In this video, we explain why a thermocouple mounted on the outside of a pipe, vessel, or component often reads differently than a probe measuring the internal fluid or gas. We explore how thermal gradients, material thermal conductivity, wall thickness, insulation, mounting methods, and ambient temperature all influence surface measurements. You’ll learn:
- Why surface temperatures rarely match internal process temperatures
- How ambient air, airflow, and surrounding heat sources can shift readings
- How mounting method and thermal contact affect accuracy and stabilityWhen surface thermocouples are appropriate—and when an immersion probe is the better choice
Understanding these factors helps engineers, technicians, and designers select the right thermocouple style and installation method for accurate, meaningful temperature data. For help choosing the right temperature sensor for your application, contact us!