FieldengThermal & HVAC
Dew Point
Magnus dew point from dry-bulb temperature and relative humidity (a = 17.62, b = 243.12 °C).
Thermal & HVAC
Magnus dew point from dry-bulb temperature and relative humidity (a = 17.62, b = 243.12 °C).
App id: THERM-11. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
Tdp = b γ / (a − γ); γ = ln(RH) + a T / (b + T)Inputs
| Name | Unit |
|---|---|
| Dry-bulb temperature (camera) | C |
| Relative humidity (camera) | % |
Outputs
| Name | Unit |
|---|---|
| Dew point (hero result) | C |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
| When | Observation | Severity |
|---|---|---|
RH > 0.7 | High relative humidity | caution |
RH < 0.2 | Low relative humidity | info |
Assumptions
- RH is a fraction (enter %). RH = 0 is rejected because ln(0) is undefined.
Provenance
- WMO Magnus over water. Valid roughly −45 °C to 60 °C. Not ice.