RASP-SENSE-HAT-ASTRO-PI-Pression

Senseur de Pression

The Sense HAT features a number of sensors, including a pressure sensor.

Le source anglaise de cette traduction se trouve sur sur www.raspberrypi.org/learning/astro-pi-guide/sensors/pressure.md

Qu'est ce que la pression et comment la mesurer?

Pressure, generally speaking, is the force applied to a surface per unit of area. Imagine a brick sitting on a table. The force of its weight is being applied through the area of one of its faces. If you were then to balance the brick on a needle the force of its weight is concentrated on the area of the needle's tip, so the pressure being applied to the table is much higher.

Atmospheric pressure (also known as barometric pressure) is the pressure exerted by the weight of air in the Earth's atmosphere. Air pressure is pushing on every part of your body all the time. The pressure inside your body is the same as outside, though, so you don't feel anything. The unit of measurement is usually bars or millibars. One bar is about equal to the atmospheric pressure on Earth at sea level, which is 1000 millibars.

Les faits à propos de la pression

• Atmospheric pressure decreases smoothly from the Earth's surface (sea level) up to the edge of space.

• The plastic bottle above was sealed at approximately 4300 metres altitude, and was crushed by the increase in atmospheric pressure at 2700 metres and then 300 metres as it was brought down towards sea level.
• Animal and plant life need atmospheric pressure in order to survive. The air above 8000 metres altitude is dangerous to humans and has been named the Death Zone by mountain climbers. The summit of Mount Everest is in this zone.
• The limite d'Armstrong is the altitude beyond which humans absolutely cannot survive in an unpressurised environment. This is between 18900 and 19350 metres, where water boils at the normal temperature of the human body.
• The ISS maintains an orbit with an altitude of about 400 km (400000 metres), which is way past the Armstrong line and right out in the vastness of space without any atmosphere (zero millibars). However, the air pressure inside the ISS is maintained at about 1013 millibars, which is nice and comfortable for the crew.

Qu'est ce que la pression?

1. Open Python 3 from a terminal window as sudo by typing:

sudo idle3 &

2. A Python Shell window will now appear. The terminal window can now be closed.

3. Select File > New Window (fichier > nouvelle fenêtre).

4. Enter the following code:

from sense_hat import SenseHat

sense = SenseHat()
sense.clear()

pressure = sense.get_pressure()
print(pressure)

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Source: Getting Started with Astro PI et Astro-Pi Guide proposé par Raspberry Pi Learning Resource (www.raspberrypi.org)

Licence Creative Commons - CC-BY-SA
The learning resource is provided for free by the Raspberry Pi Foundation under a Creative Commons licence.
Find more at raspberrypi.org/resources and github.com/raspberrypilearning.

Traduction réalisée par Meurisse. D pour shop.MCHobby.be - Licence CC-BY-SA.
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