Is my pressure sensor faulty if the value is lower than the weather reports?
No. This is expected behavior due to sea-level normalization used by weather services.
Overview
Atmotube PRO 2 features a high-precision Infineon DPS310 barometric pressure sensor, designed to measure absolute (station) atmospheric pressure at the device’s physical location. However, the app allows you to choose how pressure is displayed on the main screen.
Absolute (station) pressure
Atmotube PRO 2 displays:
Actual atmospheric pressure at the device’s altitude
Measured directly by the onboard sensor
Without mathematical adjustment to sea level
This makes readings:
physically accurate,
consistent across locations,
reliable for detecting weather-related pressure changes.
Why Values May Differ from Weather Apps
Most weather apps and city forecasts display sea-level pressure (also called normalized pressure), which is:
mathematically adjusted to what pressure would be at sea level,
independent of the user’s actual elevation.
Because atmospheric pressure decreases with altitude:
~1 hPa per 8–9 meters of elevation,
differences of 20–60 hPa compared to weather apps are completely normal.
Sea-level pressure display on the main screen
For user convenience, the Atmotube PRO 2 app allows you to display sea-level–adjusted pressure on the detailed main screen.
How to enable
Open the app
Go to Settings → Units
Enable “Sea-level pressure on main screen”
Location permission is required
To enable this feature, the app must have permission to access your location while the app is in use, so it can determine altitude.
Data consistency
Main screen: absolute or sea-level pressure (user-selectable)
Graphs & exports: always absolute pressure
This ensures scientific consistency while allowing easy comparison with weather services.
Manual conversion to sea-level pressure (optional)
If you want to compare Atmotube PRO 2 readings with weather services, you can manually estimate sea-level pressure using your elevation.
Simple approximation
For everyday use, a linear approximation is sufficient:
Measured pressure (hPa) + Current Altitude (meters) / 8.5 = Sea-level Pressure (hPa)
Physical model
A more exact conversion uses the barometric formula:
P₀ is sea-level pressure
P is measured (absolute) pressure
T is temperature (K)
M is the molar mass of air
g is gravitational acceleration
z is sensing altitude above sea level
R* is the gas constant
R*T/Mg gives the scale height (approximately equal to 8.4 km for the troposphere).
For most users, the simple linear approximation above is accurate enough and easier to apply.