Dive Regulator
A dive regulator is used to draw the correct amount of
gas from the cylinder for breathing, and allowing exhaled air out. It
is divided into two parts. The first stage is the component that attaches
to the cylinder and converts the pressurized air inside to what's called
intermediate pressure (less pressure than in the tank but still higher
than breathing pressure). The second stage is the component that you
put in your mouth to breathe. It reduces the air coming from the first
stage regulator to ambient pressure (the right pressure for you to breathe).
The dive regulator controls the flow of air, so that the air pressure
within the diver's lungs equals the pressure of the water. This is essential
because the pressure of water is much greater than gas. The air breathed
in must be at the same pressure as the water, which changes with depth,
to ensure ease of breathing. Without pressurized air, a diver’s
lungs and sinuses would collapse from the pressure of deep diving.
Emile Gagnan and Jacques Cousteau invented the modern dive regulator
and an improved autonomous diving suit. In 1942, they redesigned a car
regulator and invented a demand regulator that would automatically fresh
air when a diver breathed. A year later in 1943, Cousteau and Gagnan
began selling the Aqua-Lung.