Negative pressure

As negative pressure (fachsprachlich: negative pressure ) refers to the condition of the lower pressure in a given volume. A negative pressure when the pressure within the volume is less than the ambient pressure.

The term vacuum is useful only if the selected reference pressure is known. Under pressure will be referred to in this context as the negative pressure or suction. In current standards bar is used as the reference pressure 1 ( to 1978 atm).

For example, a negative pressure inside the device is generated in the vacuum cleaner, so that the air at the end of the tube ( " sucked in ") by the external atmospheric pressure is blown.

At sea level, a maximum negative pressure of 1 bar is possible.