| Organization | Standard | Alpha | Nominal Resistance(ohms) At 0°C  | 
            
|---|---|---|---|
| International Electrotechnical Commission (Supersedes BS & DIN)  | 
                IEC 60751: 2022 | 0.00385 | 
                100 | 
| ASTM International | ASTM E1137/E1137M-08 (2020) | 0.00385 | 100 | 
| American Scientific Apparatus Makers Association (SAMA)  | 
                RC21-4-1966 | 0.003923 | 98.129 | 
| British Standards Association  | 
                b.S. 1904-1964 | 0.00385 | 100 | 
| Normenstelle Elektrotechnik  | 
                DIN 43760 | 0.00385 | 100 | 
| US Department of Defense  | 
                MIL-T-24388 | 0.00392 | 100 | 
| Tolerance Class | Tolerance Value (°C) | Temperature Range of Validity of Tolerances  | 
            
|---|---|---|
| W 0.1 | ±(0.1° + 0.0017[t]) | -50° to 250° | 
| W 0.15 | ±(0.15° + 0.002[t]) | -100° to 450° | 
| W 0.3 | ±(0.3° + 0.005[t]) | -196° to 661° | 
| W 0.6 | ±(0.6° + 0.01[t]) | -196° to 661° | 
| Tolerance Class | Tolerance Value (°C) | Temperature Range of Validity of Tolerances  | 
            
|---|---|---|
| F 0.1 | ±(0.1° + 0.0017[t]) | -50° to 250° | 
| F 0.15 | ±(0.15° + 0.002[t]) | -50° to 450° | 
| F 0.3 | ±(0.3° + 0.005[t]) | -50° to 661° | 
| F 0.6 | ±(0.6° + 0.01[t]) | -50° to 661° | 
| Tolerance Class | Tolerance Value (°C) | Temperature Range of Validity of Tolerances  | 
            
|---|---|---|
| AA | ±(0.1° + 0.0017[t]) | -50° to 250° | 
| A | ±(0.13° + 0.0017[t]) | -100° to 450° | 
| B | ±(0.25° + 0.0042[t]) | -196° to 600° | 
| C | ±(0.6° + 0.01[t]) | -196° to 600° |