Lesson 1, Topic 1
In Progress

High Pressure Gauge


The high pressure gauge is used to measure air pressure, or other type of gas mixture, inside the dive bottle.


In conventional mechanical gauges the pressure is indicated by a pointer moving on a circular dial, graduated in bar (kg/cm2) or PSI (psi/square inch).

Usually the dial has the sector between 0 and 50 bar painted red. When the pointer enters this sector it is said that the diver has entered the reserve. This means that the dive is at the end and the return to the surface must begin immediately.

The dive gauge is connected, through a special hose, to the high pressure output (HP) of the 1st floor of the regulator, measuring the pressure inside the bottle as soon as the tap is opened.


This is intended to measure the pressure of the bottles to the surface.


This indicates the air pressure in the bottle during the dive.

The dive gauge is a mandatory instrument for the diver as it allows him to control the amount of air in the bottle so that he can return to the surface before the air finishes.

Like the other instruments described above, the dive gauge is a passive control system. This means that the diver should have a habit of consulting him regularly.


On the electronic pressure gauge, the pressure value is displayed on a digital display.

In addition to the numerical representation, usually the pressure value is also plotted by a column, where the reserve zone is marked.

These gauges are already embedded in the dive computers.


The manometer hose should be treated with care to avoid deterioration, such as toric joints sealing the connection between the hose and the pressure gauge, which must be kept clean and well lubricated. Attention to the sand that can be glued to the toric joints, for it is half way to its destruction.