The tolerance class of a Pt100 sensor defines how closely the sensor's actual resistance values match the ideal curve defined by the IEC 60751 standard. There are five quality classes with the following tolerances at 0 °C.
Class B: |
±0.3 K |
Class A: |
±0.15 K |
Class B 1/3: |
±0.1 K |
Class B 1/5: |
±0.06 K |
Class B 1/10: |
±0.03 K |
The table below illustrates the tolerances for each PT100 sensor class at different temperatures
New standard
The manufacturing tolerances were formerly sub-divided into the accuracy Classes A and B (see above). The new standard contains the additional classes AA and C. Within the validity range of every class for wire-wound resistors and film resistors, the limit deviations (tl) are given in dependence on the temperature (t) in Celsius:
Class AA: |
tl = 0.1 K + 0.0017 · t |
Class A: |
tl = 0.15 K + 0.002 · t |
Class B: |
tl = 0.30 K + 0.005 · t |
Class C: |
tl = 0.6 K + 0.01 · t |