Hygrometer test on OE24.at | Test & Comparison 2022

1. How hygrometers work and where they can be used as practical helpers

The first reliable measurements of humidity were made by Horace-Bénédict de Saussure in 1783. Technology has changed a lot since then, so you can now choose between three types of hygrometer:

Humidity is generally measured in three different ways:

1.1. The absorption method works with steam

Substances designated as "hygroscopic" remove the water vapor present in the room air. By weighing inside the device, the absolute humidity within a room can be determined after the steam has been removed.

1.2. A hair hygrometer changes lengthwise

With a hygrometer you can ensure optimal air conditions in your home.

Hygrometers based on this technology use synthetic fibers resembling a hair. They are calibrated to a certain length and change their length depending on the existing room humidity.

1.3. Psychrometers measure relative humidity

The ball of a liquid thermometer is wrapped with a damp cloth, whereby the evaporative cooling causes the displayed temperature to drop. At the same time, a dry thermometer shows the ambient temperature. The relative humidity can be read from the difference between the two values ​​using a psychrometer chart.

1.4. The dew point method works with a mirror

A mirror is cooled in the room air until water condenses on the surface. The temperature of the mirror and that of the air in the room are measured, with the difference in the values ​​indicating the humidity.

1.5. The different types

The devices in different categories of our comparison, which can be used in private households, are either electrical or mechanical variants. The addition "thermo" or thermo-hygrometer provides information that the hygrometer also acts as a thermometer.

An analogue hygrometer is always a mechanical type that can be calibrated manually. They work energy-saving without batteries and are not very maintenance-intensive. They are excellently suited for determining the room humidity.

Digital hygrometers are capable of functioning as barometers, thermometers and hygrometers as well. They measure and store various values. In some cases, they even emit an alarm signal when certain limit values ​​are exceeded or not reached.

Hygrometers with apps consist of a measuring unit, while the values ​​are not shown on the display of the devices, but on the app in the smartphone.

In general, the different types can be used to measure the humidity in entire rooms, terrariums or cupboards. A hygrometer in the humidor is also very popular and widespread among cigar lovers. In contrast to most rooms, however, there should be no dryness here, but a defined humidity, so that the aromas are preserved and the cigars do not dry out.