Modifications

[[Fichier:Hygrometrie-et-temperature.jpg|640px]]<small><br />[https://commons.wikimedia.org/wiki/File:Hygrom%C3%A9trie_et_temp%C3%A9rature.jpg#/media/File:Hygrom%C3%A9trie_et_temp%C3%A9rature.jpg Hygrométrie et température]. Sous licence CC BY-SA 3.0 via Wikimedia Commons</small>

[[Fichier:Hygrometrie-et-temperature.jpg|640px]]<small><br />[https://commons.wikimedia.org/wiki/File:Hygrom%C3%A9trie_et_temp%C3%A9rature.jpg#/media/File:Hygrom%C3%A9trie_et_temp%C3%A9rature.jpg Hygrométrie et température]. Sous licence CC BY-SA 3.0 via Wikimedia Commons</small>

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Lorsque vous sortez une bouteille ou une canette du frigo, vous voyez rapidement apparaître de l'eau à la surface de celle-ci. Cela arrive parce que l'air est refroidit autour de la bouteille/canette. Comme l'air refroidit, il devient moins capable de retenir de la vapeur d'eau en suspension. De fait, la vapeur d'eau qui ne peut plus rester en suspension se transforme en eau liquide. Cela s'appelle la condensation.  

When you take a cold can or bottle out of the fridge you see water appearing on it. This happens because the cold bottle is cooling the air around it, causing the air to be less capable of suspending water vapour. This then causes the water vapour that can't be suspended to turn back into liquid water. This is called condensation. So, given this information, we next need to understand that there are two ways that we can measure humidity:

Cette information connue, nous devons maintenant comprendre qu'il y a deux façons de mesurer l'humidité:

 

* L'humidité '''Absolue''' ***traduction*** humidity is the total mass of water vapour suspended in a given volume of air. Temperature is not taken into consideration. It's usually expressed as grams of water per cubic metre of air.

<nowiki>- *Absolute* humidity is the total mass of water vapour suspended in a given volume of air. Temperature is not taken into consideration. It's usually expressed as grams of water per cubic metre of air.

* L'humidité '''Relative''' , however, is expressed as a percentage. For any given air temperature there is a maximum amount of water vapour that it can suspend. Relative humidity is the percentage of actual water vapour present, compared to the maximum possible amount.</nowiki>

- *Relative* humidity, however, is expressed as a percentage. For any given air temperature there is a maximum amount of water vapour that it can suspend. Relative humidity is the percentage of actual water vapour present, compared to the maximum possible amount.</nowiki>

A known amount of water vapour will result in different relative humidity readings, depending on the temperature of the air and the ability of the air to suspend it. So a low air temperature might give a high relative humidity reading because the air can't suspend much more water vapour. Increasing the temperature of the air and keeping the same amount of water vapour will cause the relative humidity reading to drop, because the maximum amount of water vapour that could be suspended has increased.

A known amount of water vapour will result in different relative humidity readings, depending on the temperature of the air and the ability of the air to suspend it. So a low air temperature might give a high relative humidity reading because the air can't suspend much more water vapour. Increasing the temperature of the air and keeping the same amount of water vapour will cause the relative humidity reading to drop, because the maximum amount of water vapour that could be suspended has increased.