When you’re working with projects involving vacuum pumps, a vacuum gauge will show you the pressure in the chamber being evacuated. There are many different approaches to measuring the pressure in a vacuum, but we’ll focus on one of the most common, called the Bourdon pressure gauge.

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At the heart of the Bourdon gauge is a C-shaped flattened tube that is connected to the chamber being evacuated. The removal of the air in the tube causes the tube to bend slightly, which moves a mechanism attached to the end of the tube. This mechanism amplifies and converts the bending motion into rotation, moving the pressure dial to indicate the pressure in the tube.

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Vacuum Gauge Selection Chart
Different types of pressure gauges have different pressure ranges that they can measure. If you’re trying to reach a specific pressure, the following chart can help you find a gauge that can read that pressure.