Which standard defines platinum RTD characteristics?
A. IEC 60751
B. IEC 70751
C. IEC 80751
D. IEC 90751
View Answer
Answer: A
Explanation:
The IEC 60751 standard defines the characteristics, tolerances, temperature coefficients, and resistance-temperature relationship of industrial platinum RTDs such as Pt100 and Pt1000.
IEC 60751 specifies:
Resistance values at various temperatures
Temperature coefficient (α = 0.00385 Ω/Ω/°C)
Accuracy classes (Class AA, A, B, and C)
Tolerance limits
Callendar-Van Dusen coefficients
Construction and performance requirements
For example, according to IEC 60751:
- 0°C = 100.00 Ω
- 100°C ≈ 138.51 Ω
- 200°C ≈ 175.86 Ω
The standard also uses the Callendar-Van Dusen equation to accurately model the resistance-temperature relationship of platinum RTDs.
Why the other options are incorrect:
- IEEE 802.3 → Ethernet networking standard
- ISA 5.1 → Instrumentation symbols and identification standard
- API 650 → Standard for welded storage tanks
Because IEC 60751 is the internationally recognized standard governing platinum RTD characteristics, Option A (IEC 60751) is the correct answer.