RTD Standards

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 

 

Parameter

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

 

RESISTANCE MATERIALS

  1.    Platinum
  2.    Nickel
  3.    Copper
  4.    Balco (rare

 

Troubleshooting

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.