Why do we use Helium? Helium is a very light inert gas. It is used by technical divers to reduce narcosis when diving at deeper depths. With normal air (21% oxygen/ 79% Nitrogen) nitrogen narcosis becomes an issue at these depths.
Why is helium used in diving cylinders?
Air contains a large amount of nitrogen and the solubility of gases in liquids increases with increase in pressure. Therefore, air in oxygen cylinders used for diving is diluted with helium gas. … This is done as He is sparingly less soluble in blood.
Why are the tanks used by scuba divers filled with air diluted with helium?
Answer: Hence scuba diver use a tank filled with air diluted with helium (11.7% helium, 56.2% nitrogen and 32.1% oxygen) to avoid bends as well as toxic effects of high concentration of nitrogen in the blood because of increase in pressure underwater and decreasing pressure towards the water surface.
Why do divers have squeaky voices?
Finally, a question we’re asked often: Does heliox give divers a squeaky voice? Yes, it does! The effect is the same as inhaling helium from a birthday balloon – and surface crews often pitch-correct radio communications to make them more understandable.
Is helium used in scuba diver tank?
For normal, no decompression dives, helium is not used in scuba tanks, just normal air( 21% Oxygen and 79% Nitrogen). Technical divers who go beyond recreational depths (30m – 40m) employ the use of trimix. Trimix is a mixture of oxygen nitrogen and helium.
Why regular air Cannot be used in divers tank?
Because our body needs it for its metabolic function, the air in a SCUBA tank cannot be devoid of oxygen. But oxygen does have toxic effects on the body when it is subjected to higher levels of pressure, specifically the central nervous system, pulmonary function, and ocular function.
Which gas is used in scuba tank?
Nitrogen (N2) is a diatomic gas and the main component of air, the cheapest and most common breathing gas used for diving. It causes nitrogen narcosis in the diver, so its use is limited to shallower dives. Nitrogen can cause decompression sickness.
What is the composition of gas in the tanks used by the scuba divers?
Nowadays it is filled with 11.7% helium, 56.2% nitrogen and 32.1% oxygen.
Why do divers tap their heads?
These surface communication signals involve the whole arm so that boat captains and surface support staff can easily understand a diver’s communication from far away. The “OK” sign is made by joining both arms in a ring above the head, or if only one arm is free, by touching the top of the head with the fingertips.
Can divers communicate underwater?
Scuba divers are trained to use hand signals to communicate with their buddies. They also use underwater writing boards, which allow for better communication.
Why do scuba divers tap their head?
How to do it: Communicate “OK” above water by joining both hands to create a ring with your arms over the top of your head; if you can only use one arm, you can do this signal by touching the top of your head with your fingertips. To do the “Problem” or “Help” signal, wave your arm over your head as if to say, “hi.”
At what depth do divers use helium?
Commercial and exotic gases
This mixture of helium and oxygen can be used at depths of up to 984 feet (300 m). Any deeper than that requires divers to replace helium with hydrogen. Helium becomes narcotic at these depths, and the body becomes susceptible to High Pressure Nervous Syndrome (HPNS).
Why don t scuba divers fill their tanks with pure oxygen?
Diving with pure oxygen deeper than 20 feet can cause a person to absorb more oxygen than his system can safely handle, leading to central nervous system (CNS) oxygen toxicity. CNS oxygen toxicity causes a diver to go into convulsions (among other things).
How deep can you dive with Hydrox?
Comex subsequently developed procedures allowing dives between 500 and 700 metres (1650 to 2300 feet) in depth, while breathing gas mixtures based on hydrogen, called hydrox (hydrogen-oxygen) or hydreliox (hydrogen-helium-oxygen).