The global impact of COVID-19 on our people and the global economy is significant, and Watlow has taken a comprehensive approach to deal with the current crisis. Our contingency planning includes protecting our team members, communicating often with our customers and partners and maintaining the continuity of supply lines.

At the beginning of the pandemic, we set two priorities that guide our responses and decisions: the health and safety of our team members while continuing to supply essential products needed by our customers.

If you have questions about how the pandemic is impacting Watlow or Watlow’s response, please contact your Watlow representative.

RTD Tolerances, Classes and Comparisons

Platinum RTD Tolerance Values

Temperature °C Resistance Value Ω Tolerance DIN-IEC-751
Class A
°C (Ω)
Class B
°C (Ω)
-200
-100
0
100
200
18.52
60.26
100.00
138.51
175.86
±0.55-(±0.24)
±0.35-(±0.14)
±0.15-(±0.06)
±0.35-(±0.13)
±0.55-(±0.20)
±1.3-(±0.56)
±0.8-(±0.32)
±0.3-(±0.12)
±0.8-(±0.30)
±1.3-(±0.48)
300
400
500
600
650
212.05
247.09
280.98
313.71
329.64
±0.75-(±0.27)
±0.95-(±0.33)
±1.15-(±0.38)
±1.35-(±0.43)
±1.45-(±0.46)
±1.8-(±0.64)
±2.3-(±0.79)
±2.8-(±0.93)
±3.3-(±1.06)
±3.6-(±1.13)

RTD Tolerance Class Definitions

DIN class A: ± [ (0.15 + 0.002 | t | ] °C 
DIN class B: ± [ (0.30 + 0.005 | t | ] °C


RTD Resistance Wire Comparisons

Element Metal Temperature Range Benefits Base Resistance TCR (Ω/Ω/°C)
Platinum -260 to 850°C
(-436 to 1562°F)
Best stability, good linearity 100 Ω at 0°C 0.00385 (DIN-IEC-761), 0.003916 (JIS 1604-1981)
Copper -100 to 260°C
(-148 to 500°F)
Best linearity 10 Ω at 25°C 0.00427
Nickel -100 to 260°C
(-148 to 500°F)
Low cost, High Sensitivity 120 Ω at 0° C 0.00672