Stull approximation: T_w = T atan[0.151977 √(RH+8.313659)] + atan(T+RH) − ... Simpler: T_w ≈ T × atan(0.151977(RH+8.31)^0.5) + atan(T+RH) − atan(RH-1.676331) + 0.00391838 RH^1.5 atan(0.023101 RH) − 4.686035.
| Constant | Symbol | Value |
|---|---|---|
| Speed of light | c | 2.99792458×10⁸ |
| Planck's constant | h | 6.62607015×10⁻³‴ |
| Boltzmann constant | kʙ | 1.380649×10⁻²³ |
| Avogadro's number | Nₐ | 6.02214076×10²³ |
| Gravitational constant | G | 6.6743×10⁻¹¹ |
| Gas constant | R | 8.31446 |
| Elementary charge | e | 1.602176634×10⁻¹⁹ |
| Electron mass | mₑ | 9.1093837015×10⁻³¹ |
| Proton mass | mₚ | 1.67262192369×10⁻²⁷ |
| Fine-structure constant | α | 7.2973525693×10⁻³ |
Enter the values for the patient or scenario you are assessing. Stull approximation: T_w = T atan[0.151977 √(RH+8.313659)] + atan(T+RH) − ... Simpler: T_w ≈ T × atan(0.151977(RH+8.31)^0.5) + atan(T+RH) − atan(RH-1.676331) + 0.00391838 RH^1.5 atan(0.023101 RH) − 4.686035. Use the wet bulb temp result to inform your clinical assessment.