How does a barometer work?

How does a barometer work?

For centuries, the barometer has been telling us what the weather is like. The Ocean Clock barometer is not just a weather device but a true deco object, in line with tide clocks. So, how does a barometer work?

For those who have never seen this type of device on their parents’ or grandparents’ wall, let us explain in a few words what a weather barometer is and its utility in everyday life.

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What do we measurewith a barometer?

One needs to know that atmospheric pressure, measured in hectopascal (hPa), varies according to several factors like altitude. Indeed, the higher the altitude, the weaker the atmospheric pressure, and that is due to the low air volume available in altitude.

Therefore, it is important to set your weather barometer correctly depending on the pressure present in your place of residence. 


Keep in mind that when we use a barometer, it is not the pressure value that matters but its variation. Pressure changes are mostly linked to weather events, like depression and anticyclones. Therefore, by measuring this variation, the barometer will indicate you the weather forecast for the next hours (12 to 24h), and tell you if the weather is about to improve or worsen.

A quick way to figure out what the sky colour will be today.

How doesa barometer work?

The very first barometer appeared in 1643 thanks to the Italian physicist Torricelli who used a mercury-based device to measure atmospheric pressure. Since that time, other physicists have developed new techniques for measuring pressure. That is why there are different kinds of barometers: water, gas and aneroid barometers.

Nowadays, aneroid barometers are the most commonly used barometers to forecast the weather as their process enables to obtain more accurate and safe indications, unlike mercury barometers that cannot be sold anymore because of their toxicity.

Gas or water barometers, very sensitive to temperature changes, are less precise and need their forecasts to be adjusted.


It is for all these reasons that, at Ocean Clock, we chose to develop a handed barometer that is called aneroid. Technically speaking, how does a handed barometer work?

Created in 1844 by a Frenchman called Lucien Vidie, the aneroid barometer is liquidless and works thanks to a hermetic box whose air was partly removed, also called Vidie capsule.

When air pressure changes, the box becomes distorted which triggers a mechanism that will move the hand according to that pressure.

This specific type of mechanism does not require any energy source (battery) to work, you will just have to tap on the glass to make it react to air pressure and make the hand move. Therefore, the variation of the hand’s position, that is to say the pressure, enables to give the weather forecast for the next hours.

A reference pointer can also be found on the aneroid barometer to help you see the pressure variation in comparison with the last indication and determine the future weather conditions.

HOW TO READa barometer

If you wish to learn more on how to read a handed barometer and interpret its forecasts,

go now to our page that explains how to read a barometer.


There you go, you now know how a barometer works! You wish to master weather forecasts?

For better precision, it is necessary to combine this wood barometer to other measuring tools such as the thermometer, hygrometer (tool to measure air humidity) and anemometer (wind-speed-measuring tool). Once you have mastered all these tools, you will become a true weather master and the weather will no longer have any secrets for you.

You wish to add the Ocean Clock barometer to your decoration?

Discover right away our new french creation and its different variants: our collection of barometers