Two standards are available for platinum RTDs:
- American standard
- European standard
There are two resistance tolerances specified in DIN/IEC751:
Class A = ±(0.15 + 0.002*t)°C or 100.00 ±0.06 Ω at 0ºC
Class B = ±(0.3 + 0.005*t)°C or 100.00 ±0.12 Ω at 0ºC
Maximum Operating Range = -195°C to 660°C
Interchangeability = ±.25°C at 0°C
Stability = Less than .05°C shift per year.
Nominal Operating Current = 1 milliampere
Maximum Safe Current = 20 Milliampere
- Balco (rare
Problems associated with RTD assemblies tend to be straightforward and easily fixed. As RTD elements are susceptible to damage by vibration or mechanical shock, the most likely problem will be that the element is open circuit. Depending on the type of assembly, this can be determined easily with a multimeter.