Correct Answer:
A. Platinum Wire Wrapped Around a Ceramic Core: The sensing element consists of a thin platinum wire wound around a ceramic core. The resistance of the platinum wire changes with temperature, and this change is used to measure temperature.
Explanation:
- A. Correct: The PT100 probe uses a sensing element made of a thin platinum wire wound around a ceramic core. Platinum is chosen for its stable and predictable change in resistance with temperature, providing accurate temperature measurements.
- B. Incorrect: Copper wire is not used in PT100 probes. While copper wire does change resistance with temperature, it does not have the stability and precision required for PT100 sensors.
- C. Incorrect: This describes a thermocouple, not a PT100 probe. Thermocouples use two different metals to create a voltage based on temperature differences.
- D. Incorrect: While resistance film on a substrate can be used in some temperature sensors, it is not the typical construction for PT100 probes. PT100 sensors rely on platinum wire for its accuracy and stability.
Correct Answer:
A. Platinum Wire Wrapped Around a Ceramic Core: The sensing element consists of a thin platinum wire wound around a ceramic core. The resistance of the platinum wire changes with temperature, and this change is used to measure temperature.
Explanation:
- A. Correct: The PT100 probe uses a sensing element made of a thin platinum wire wound around a ceramic core. Platinum is chosen for its stable and predictable change in resistance with temperature, providing accurate temperature measurements.
- B. Incorrect: Copper wire is not used in PT100 probes. While copper wire does change resistance with temperature, it does not have the stability and precision required for PT100 sensors.
- C. Incorrect: This describes a thermocouple, not a PT100 probe. Thermocouples use two different metals to create a voltage based on temperature differences.
- D. Incorrect: While resistance film on a substrate can be used in some temperature sensors, it is not the typical construction for PT100 probes. PT100 sensors rely on platinum wire for its accuracy and stability.