Which device is specifically used to measure low pressures and vacuums?

The inclined manometer is specifically designed to measure low pressures and vacuums with a high degree of accuracy. Its construction involves a U-shaped tube filled with liquid, often water or mercury, where one side is open to the atmosphere and the other side is connected to the pressure source. The inclination of the tube enhances sensitivity to small pressure changes, allowing for precise readings in low-pressure scenarios.

In the case of low pressures, the horizontal leg of the manometer minimizes the effect of atmospheric pressure variations, which is crucial for accurate measurements. The inclination also allows for a greater length of liquid column to be utilized in the measurement, thus enabling the accurate detection of very small pressure differences.

Other devices, such as thermocouples, transducers, and bourdon tubes, serve different functions. Thermocouples are primarily used for temperature measurements, transducers convert one form of energy to another (such as pressure to electrical signals) but are not specifically tailored for low-pressure readings, and bourdon tubes are typically used for higher pressures. This makes the inclined manometer uniquely suited for applications requiring the measurement of low pressures and vacuum conditions.