Non-contact high-temperature measurement: Compared with thermocouples, which statement best characterises radiation pyrometers used in industry?

Difficulty: Easy

Correct Answer: can measure higher temperature

Explanation:


Introduction / Context:
Temperature sensors fall into contact (thermocouples, RTDs) and non-contact (radiation/optical pyrometers) categories. Selection depends on temperature level, response needs, accessibility, and process environment. This item asks for the most distinguishing advantage of radiation pyrometers relative to thermocouples.


Given Data / Assumptions:

  • Typical industrial use over a wide temperature span.
  • Direct line-of-sight is available for the pyrometer.
  • Comparison focuses on principal capability rather than niche models.


Concept / Approach:
Radiation pyrometers infer temperature from thermal radiation, enabling measurement at very high temperatures beyond the safe or practical limits of contact sensors. They are also suitable for moving or rotating targets since no contact is required. While response speed can vary by design, modern pyrometers are often very fast; their headline advantage remains access to higher temperature ranges and non-contact operation.


Step-by-Step Solution:

Identify thermocouple limits: drift/oxidation and sheath limits constrain the top measurable temperature.Recognise pyrometer advantage: non-contact technique tolerates incandescent/high-temperature targets.Select the statement capturing this key benefit: “can measure higher temperature.”


Verification / Alternative check:
Specifications for optical/IR pyrometers routinely extend well above 1000°C, where many thermocouples face life or accuracy limitations without elaborate protection.


Why Other Options Are Wrong:

Slower response — not universally true; many pyrometers are very fast.Cannot measure moving objects — incorrect; non-contact is ideal for moving targets.More affected by corrosive atmosphere — false; non-contact and remote optics reduce exposure.Require physical contact — the opposite of how pyrometers work.


Common Pitfalls:
Overgeneralising response time; model specifics matter. The most robust, broadly true differentiator is the higher measurable temperature range with non-contact operation.


Final Answer:
can measure higher temperature

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