Atmospheric lock (lock chamber) - a sealed device or structure that allows communication between zones with different pressures and different atmospheric gases on both sides of the device, including in the case of different aggregate states of matter, such as, for example, in the case of lock devices on underwater vehicles.
If it is necessary to use such a device to transfer from one medium to another, it is sealed, after which the state of the environment in it is leveled with the surrounding conditions, the transition to which is carried out when using it.
Application
Before opening one of the doors, the air pressure of the airlock - the space between the doors - is equalized with the pressure of the medium located behind the next door.
A gradual change in pressure reduces temperature fluctuations (see Boyle's Law ), which helps to reduce fogging and condensation, reduces the load on air seals, and also makes it possible to safely check and operate a spacesuit or a height-compensating suit .
In the event that a person without a spacesuit moves between environments with significantly different pressures, the atmospheric airlock gradually changes the pressure to facilitate internal adaptation of the sinuses and to prevent decompression sickness . This is extremely important when underwater diving , while the diver may need to wait about a few hours in the gateway, in accordance with the decompression tables .