absolutehumidity adapter for ioBroker

build absolute humidity from actual temperature and relative humidity

Calculation method

The adapter uses empirical Magnus approximation formulas to calculate the saturation vapor pressure from temperature and relative humidity.

Absolute humidity is calculated from the saturation vapor pressure using the Magnus/Bolton approximation and the ideal gas law. The result is returned in g/m³.
Dew point temperature is calculated using the Magnus formula with Sonntag coefficients. The result is returned in °C.

Small deviations from online tables are expected because different tables often use different Magnus, Tetens, Sonntag, Bolton or Buck coefficient sets.

The instance page is interactive, allowing for the calculation of absolute humidity, dew point temperature, and ventilation recommendations based on data recorded via analog or manual methods. Simply enter the values, and the result will be displayed automatically.

Installation

As long as the adapter is not yet listed in the stable repository, it can be installed manually from NPM. Note: NEVER install it from GitHub.

Installation Link: https://github.com/BenAhrdt/ioBroker.absolutehumidity

Create a tab in the tab bar

Use the pin to create a tab in the tab bar. Use "+ Add device" to add a device.

Add a Device

To add a device, you must assign a name and select the two states for temperature and relative humidity. Optionally, you can specify whether these two values should also be included (again) in the adapter's objects.

Tile view

The tiles for outdoor use are displayed in green, and those for indoor use in blue. In the tile view, the tiles are sorted in ascending order, that is, from dry to more humid. (If the green tile appears first, ventilating the room might be advisable)

Object view

Iobroker Forum Link

https://forum.iobroker.net/topic/85455/test-adapter-absolut-humidity

Changelog

0.1.6 (2026-09-28)

Rename the visible Device Manager references to Config Manager in the adapter configuration and translations.
Add delayed device configuration backups with manual restore and startup recovery when no device configuration exists.

0.1.5 (2026-09-27)

Update the repository-check dependencies and test the adapter on Node.js 26.

0.1.4 (2026-09-21)

Keep long Device Manager measurements readable with a smaller value font and at most two decimal places.

0.1.3 (2026-09-21)

Restore the regular adapter configuration page with interactive outdoor and indoor preview cards, and provide a link to the Device Manager in Config Manager.

0.1.2 (2026-09-20)

Keep the Device Manager in the adapter configuration instead of a separate Admin tab. Render the four live measurements through one shared HTML row template per card; Admin's read-only numeric state control otherwise adds a progress indicator for percent and bounded states.

Collaboration

The adapter was developed in collaboration with Joerg Froehner

License

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.