RTD Standards

RTD Standards

There are two standards for platinum RTDs: The European standard (also known as the DIN or IEC standard) and the American standard.

The European standard, also known as the DIN or IEC standard, is considered the world-wide standard for platinum RTDs.

This standard, DIN/IEC 60751 (or simply IEC751), requires the RTD to have an electrical resistance of 100.00 O at 0ºC and a temperature coefficient of resistance (TCR) of 0.00385O/O/ºC between 0 and 100ºC.

There are three resistance tolerances for Thin Film.

RTDs specified in IEC60751:

Class AA (Formerly 1/3B) = ± (0.1+0.0017×t) °C or 100.00 ± 0.04Ω at 0°C

Class A = ± (0.15+0.002×t) °C or 100.00 ± 0.06Ω at 0°C

Class B = ± (0.3+0.005×t) °C or 100.00 ± 0.12Ω at 0°C

Also, one special class not included in DIN/IEC60751:

Class 1/10B = ±1/10 (0.3+0.005×t) °C or 100.00 ± 0.012Ω at 0°C