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Encyclopedia > Rebreather

A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. This recycling reduces the volume of breathing gas used, making a rebreather lighter and more compact than an open-circuit breathing set for the same duration in environments where humans cannot safely breathe from the atmosphere. In the armed forces it is sometimes called "CCUBA" (Closed Circuit Underwater Breathing Apparatus). For breathing apparatus used underwater, see scuba sets and rebreather and surface supplied diving. ... Air is the most common and only natural breathing gas. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... Open circuit can mean: In electronics, where there is nothing connected to a load and no current can flow. ... For breathing apparatus used underwater, see scuba sets and rebreather and surface supplied diving. ... This article does not cite any references or sources. ...

Inspiration closed circuit diving rebreather

Contents

Download high resolution version (500x667, 30 KB)rebreather inspiration front This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Download high resolution version (500x667, 30 KB)rebreather inspiration front This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ...

Basics

Rebreather technology is used in many environments:

  • Underwater - where it is sometimes known as "closed circuit scuba" or "semi closed scuba", or CCUBA = "closed circuit underwater breathing apparatus", as opposed to Aqua-Lung-type equipment, which is known as "open circuit scuba".
  • Mine rescue and in industry - where poisonous gases may be present or oxygen may be absent.
  • Space suits - outer space is, for all intents and purposes, a vacuum where there is no oxygen to support life.
  • Hospital anaesthesia breathing systems - to supply controlled proportions of gases to patients without letting anaesthetic gas get into the atmosphere that the staff breathe.
  • Submarines and hyperbaric oxygen therapy chambers - where the gas in the habitat must remain safe. Here the rebreather is big and is connected to the air in the habitat.

This article is mainly about diving rebreathers. A scuba diver in usual sport diving gear SCUBA is an acronym for Self-Contained Underwater Breathing Apparatus. ... ... Mine rescue is the specialized job of rescuing miners and others who have become trapped or injured in underground mines, often coalmines. ... Apollo 15 space suit A spacesuit is a complex system of garments, equipment, and environmental systems designed to keep a person alive and comfortable in the harsh environment of outer space. ... Layers of Atmosphere - not to scale (NOAA)[1] Outer space, sometimes simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. ... Look up Vacuum in Wiktionary, the free dictionary. ... Anesthesia (AE), also anaesthesia (BE), is the process of blocking the perception of pain and other sensations. ... USS Virginia, a Virginia-class nuclear attack (SSN) submarine Alvin in 1978, a year after first exploring hydrothermal vents. ... This article does not cite any references or sources. ...


As a person breathes, the body consumes oxygen and makes carbon dioxide. A person with an open-circuit breathing set typically only uses about a quarter of the oxygen in the air that is breathed in. The rest is breathed out along with nitrogen and carbon dioxide. General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... In order to meet Wikipedias quality standards, this article requires cleanup. ... Open circuit can mean: In electronics, where there is nothing connected to a load and no current can flow. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ...


With a rebreather, the exhaled gas is not discharged to waste. The rebreather recovers the exhaled gas for re-use. It absorbs the carbon dioxide, which otherwise would accumulate and cause carbon dioxide poisoning. It adds oxygen to replace what was consumed. Thus, the gas in the rebreather's circuit remains breathable and supports life processes. Nearly always, the oxygen comes from a gas cylinder, and the carbon dioxide is absorbed in a canister full of some absorbent chemical designed for diving applications such as Sofnalime or Dragersorb. These absorbents may contain small amounts of soda lime, but are generally less toxic. Pure oxgyen is not considered to be safe for recreational diving below 6 meters, so recreational rebreathers also have a diluent cylinder to reduce the percentage of oxygen breathed and enable them to be used to greater depths. Hypercapnia is a condition where there is too much carbon dioxide (CO2) in the body. ... Industrial compressed gas cylinders used for oxy-fuel welding and cutting of steel. ... // Soda lime is a mixture of chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent CO2 retention and carbon dioxide poisoning. ...


History of rebreathers

British navy frogman in 1945
British navy frogman in 1945
See also: Timeline of underwater technology

Around 1620 in England, Cornelius Drebbel made an early oar-powered submarine. Records show that, to re-oxygenate the air inside it, he likely generated oxygen by heating saltpetre (sodium or potassium nitrate) in a metal pan to make it emit oxygen. That would turn the saltpetre into sodium or potassium oxide or hydroxide, which would tend to absorb carbon dioxide from the air around. That may explain how Drebbel's men were not affected by carbon dioxide build-up as much as would be expected. If so, he accidentally made a crude rebreather nearly three centuries before Fluess and Davis: see this link. Image File history File links Download high-resolution version (304x629, 50 KB) Description: A British navy frogman. ... Image File history File links Download high-resolution version (304x629, 50 KB) Description: A British navy frogman. ... Timeline of underwater technology // Pre-industrial Several centuries BC: (Relief carvings made at this time show Assyrian soldiers crossing rivers using inflated goatskin floats. ... Year 1620 was a leap year starting on Wednesday (link will display the full calendar) of the Gregorian calendar (or a leap year starting on Saturday of the 10-day slower Julian calendar). ... For other uses, see England (disambiguation). ... Cornelius Jacobszoon Drebbel (Alkmaar, 1572 - London, November 7, 1633) was the Dutch inventor of the first navigable submarine in 1620. ... USS Virginia, a Virginia-class nuclear attack (SSN) submarine Alvin in 1978, a year after first exploring hydrothermal vents. ... Saltpeter is variously: potassium nitrate (niter); or sodium nitrate (soda niter) ... For sodium in the diet, see Edible salt. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Standard atomic weight 39. ... An electrostatic potential map of the nitrate ion. ... An oxide is a chemical compound containing an oxygen atom and other elements. ... Hydroxide is a polyatomic ion consisting of oxygen and hydrogen: OH− It has a charge of −1. ... // Hypercapnia (from the Greek hyper = above and kapnos = smoke), also known as CO2 Poisoning, is a condition where there is too much carbon dioxide (CO2) in the blood. ...


The first certainly known closed circuit breathing device using stored oxygen and absorption of carbon dioxide by an absorbent (here caustic soda), was invented by Henry Fluess in 1879 to rescue mineworkers who were trapped by water. Sodium hydroxide (NaOH), also known as caustic soda or lye in North America, is a caustic metallic base used in industry (mostly as a strong chemical base) in the manufacture of paper, textiles, and detergents. ... Henry Fluess, a british inventor. ... 1879 (MDCCCLXXIX) was a common year starting on Wednesday (see link for calendar). ... Chuquicamata, the second largest open pit copper mine in the world, Chile. ...


The Davis Escape Set was the first rebreather which was practical for use and produced in quantity. It was designed about 1900 in Britain for escape from sunken submarines. Various industrial oxygen rebreathers (e.g. the Siebe Gorman Salvus and the Siebe Gorman Proto) were descended from it; this link shows a Draeger rebreather used for mines rescue in 1907. The Davis Submerged Escape Apparatus (also referred to as DSEA), is an early make of oxygen rebreather invented in 1910 by Sir Robert Davis, head of Messrs. ... Ğ: For the film, see: 1900 (film). ... CGI image: 2 views of a diver wearing a Siebe Gorman Salvus rebreather The Salvus is a light oxygen rebreather for industrial use (including by firemen and in coalmine rescue) or in shallow diving. ... The Proto is a type of rebreather that was made by Siebe Gorman. ... Dräger is a big German firm who makes diving gear. ... Mine rescue is the specialized job of rescuing miners and others who have become trapped or injured in underground mines, often coalmines. ...


The first known systematic use of rebreathers for diving was by Italian sport spearfishers in the 1930s. This practice came to the attention of the Italian Navy, which developed its frogman unit, which had a big effect in World War II. Image of wartime Italian frogman. Face The 1930s (years from 1930–1939) were described as an abrupt shift to more radical and conservative lifestyles, as countries were struggling to find a solution to the Great Depression, also known in Europe as the World Depression. ... Pre-unitarian navies of the Italian states Regia Marina - Royal Navy of the Kingdom of Italy (1861 - 1946) Marina Militare - Navy of the Italian Republic (1946 - today) This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... The Decima Flottiglia MAS (Decima Flottiglia Mezzi dAssalto, also known as La Decima or Xª MAS) (Italian for 10th Assault Vehicle Flotilla) was an Italian commando frogman unit created during the Fascist government. ... Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000...


In World War II captured Italian frogmen's rebreathers influenced design of British frogman's rebreathers. Ref British commando frogmen#1942 at "April" for more information: Many British frogmen's breathing sets' oxygen cylinders were German pilot's oxygen cylinders recovered from shot-down German Luftwaffe planes. Those first breathing sets may have been modified Davis Submarine Escape Sets; their fullface masks were the type intended for the Siebe Gorman Salvus. But in later operations different designs were used, leading to a fullface mask with one big face window. One version had a flip-up single window for both eyes to let the user get binoculars to his eyes when on the surface. They used bulky thick diving suits called Sladen suits. Early British frogman's rebreathers had rectangular breathing bags on the chest like Italian frogman's rebreathers; later British frogman's rebreathers had a square recess in the top so they could extend further up onto his shoulders; in front they had a rubber collar that was clamped around the absorbent canister, as in the CGI image below. Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... Britains commando frogman force is now the SBS, which is part of the Royal Marines. ... The Deutsche Luftwaffe or   (German: air force, literally Air Weapon, pronounced lufft-va-fa, IPA: ) is the commonly used term for the German air force. ... The Davis Submerged Escape Apparatus (also referred to as DSEA), is an early make of oxygen rebreather invented in 1910 by Sir Robert Davis, head of Messrs. ... CGI image: 2 views of a diver wearing a Siebe Gorman Salvus rebreather The Salvus is a light oxygen rebreather for industrial use (including by firemen and in coalmine rescue) or in shallow diving. ... Porro-prism binoculars with central focusing Binocular telescopes, or binoculars, (also known as field glasses) are two identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. ... The Sladen Suit was a heavy type of British divers drysuit made by Siebe Gorman. ... Inspiration Closed Circuit Diving Rebreather Description A rebreather is a type of breathing equipment that provides a breathing gas containing oxygen and recycles exhaled gas. ... CGI may mean: Computer-generated imagery, a film-making technology Common Gateway Interface, a technology used in web servers CGI.pm, a Perl module used for dealing with it CGI Group, a Canadian headquartered information management company (formerly ) Computer graphics interface, a low-level interface between the Graphical Kernel System...


US Navy rebreathers were developed by Dr. Christian J. Lambertsen in the early 1940s for underwater warfare. Dr. Lambertsen, who currently works at the University of Pennsylvania, is considered by the US Navy as "the father of the Frogmen". Information about early history of USA frogman's rebreathers is scarce because the many available photographs of UDT men and training and operations rarely show a rebreather, as if there was a secrecy law against it. The United States Navy (USN) is the branch of the United States armed forces responsible for naval operations. ... Dr. Christian J. Lambertsen developed US Navy frogmens rebreathers in the early 1940s for underwater warfare. ... This article does not cite any references or sources. ... This article is about the private Ivy League university in Philadelphia. ... For the Wizard of Oz series character, see Frogman (Oz character). ... UDT may refer to: Underwater Demolition Team, American commando frogmen and the precursor to the U.S. Navy SEALs UDP-based Data Transfer Protocol, a high performance data transport protocol and its open source library User-defined type, a concept in computer science that is generally synonymous with record, structure...


Innovations in recreational diving rebreather technology

Over the past ten or fifteen years rebreather technology has advanced considerably often driven by the growing market in recreational diving equipment. Innovations include:

  • The electronic, fully closed circuit rebreather itself - use of electronics and electro-galvanic fuel cells to monitor oxygen concentration within the loop and maintain a certain partial pressure of oxygen
  • Automatic diluent valves - these inject diluent gas into the loop when the loop pressure falls below the limit at which the diver can comfortably breathe.
  • Dive/surface valves or bailout valves - a device in the mouthpiece on the loop which connects to a bailout demand valve and can be switched to provide gas from either the loop or the demand valve without the diver taking the mouthpiece from his or her mouth. An important safety device when carbon dioxide poisoning occurs.
  • Integrated decompression computers - these allow divers to take advantage of the decompression benefits provided by the ideal mix in the loop of a fully closed circuit rebreather. By monitoring the oxygen content of the mix they can work out the inert gas content and generate a schedule of decompression stops.
  • Carbon dioxide scrubber life monitoring systems - temperature sensors monitor the progress of the reaction of the soda lime and provide an indication of when the scrubber will be exhausted.

An electro-galvanic fuel cell is an electrical device used to measure the concentration of oxygen gas in SCUBA diving and medical equipment. ... In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. ... Hypercapnia is a condition where there is too much carbon dioxide (CO2) in the body. ... A Decompression Stop is a period of time a diver must spend at a constant depth in shallow water at the end of a dive in order safely to eliminate inert gases from the divers body to avoid decompression sickness. ... // Soda lime is a mixture of chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent CO2 retention and carbon dioxide poisoning. ...

Advantages of rebreather diving

Efficiency advantages

The main advantage of the rebreather over other breathing equipment is the rebreather's economical use of gas. With "open circuit" scuba, the entire breath is expelled into the surrounding water when the diver exhales. A breath inhaled from an open circuit scuba system whose cylinder(s) are filled with ordinary air is about 21%[1] oxygen. When that breath is exhaled back into the surrounding environment, it has an oxygen level in the range of 15 to 16% when the diver is at atmospheric pressure. [1] This leaves the available oxygen utilization at about 25%; the remaining 75% is lost.


At depth, the advantage of a rebreather is even more marked. The amount of CO2 in exhaled gas is not a constant percentage, but a constant partial pressure of about 0.04bar. The amount of oxygen used from each breath is about the same - so as the ambient pressure increases (as a result of going deeper), the percentage of oxygen used from each breath drops. At 30m (100ft), a diver's exhaled breath contains about 20% oxygen and about 1% CO2. In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. ...


Feasibility advantages

Long or deep dives using open circuit equipment may not be feasible as there are limits to the number and weight of diving cylinders the diver can carry. The economy of gas consumption is also useful when the gas mix being breathed contains expensive gases, such as helium. In normal use only oxygen is consumed: small volumes of expensive inert gases can be reused for many dives. 12 litre and 3 litre steel diving cylinders A diving cylinder, scuba tank or diving tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Standard atomic weight 4. ...


Other advantages

Rebreathers produce far fewer bubbles[1] and make less noise than open-circuit scuba; this can conceal military divers and allow divers engaged in marine biology and underwater photography to avoid alarming marine animals and thereby get closer to them. The electronic fully closed circuit rebreather, is able to minimise the proportion of inert gases in the breathing mix, and therefore minimise the decompression requirements of the diver, by maintaining a specific and relatively high oxygen partial pressure at all depths. The breathing gas in a rebreather is warmer and more moist than the dry and cold gas from open circuit equipment making it more comfortable to breathe on long dives and causing less dehydration in the diver. Soap bubbles Bubble may refer to: Soap bubble, spherical liquid film, also possibly of bubble gum Cavitation, pocket of air caught in a liquid Bubble (economics), where speculation causes prices to rise to unsustainable levels a (normally) transparent dome Light bulb, in theater lighting terminology [1] in poker tournaments, the... SCUBA is an acronym for Self-Contained Underwater Breathing Apparatus. ... Military diving is a branch of professional diving carried out by world armed forces. ... Various species of reef fish in the Northwestern Hawaiian Islands. ... Pink Anemonefish hiding in tentacles Underwater photography is the process of taking photographs while underwater. ... A Decompression Stop is a period of time a diver must spend at a constant depth in shallow water at the end of a dive in order safely to eliminate inert gases from the divers body to avoid decompression sickness. ... In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. ...


Parts of a rebreather

A simple naval-type diving oxygen rebreather with the parts labelled
A simple naval-type diving oxygen rebreather with the parts labelled
Back of an Inspiration Diving Rebreather, with its casing opened

A simple naval-type diving oxygen rebreather with the parts labelled I made the image with CGI. File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A simple naval-type diving oxygen rebreather with the parts labelled I made the image with CGI. File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Download high resolution version (500x667, 31 KB)rebreather inspiration back I photographed thi myself This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Download high resolution version (500x667, 31 KB)rebreather inspiration back I photographed thi myself This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ...

The loop

Although there are several design variations of diving rebreather, all types have a gas-tight loop that the diver inhales from and exhales into. The loop consists of components sealed together. The diver breathes through a mouthpiece or a fullface mask (or with industrial breathing sets, sometimes a mouth-and-nose mask). This is connected to one or more tubes bringing inhaled gas and exhaled gas between the diver and a counterlung or breathing bag. This holds gas when it is not in the diver's lungs. The loop also includes a scrubber containing carbon dioxide absorbent to remove from the loop the carbon dioxide exhaled by the diver. Attached to the loop there will be at least one valve allowing injection of gases, such as oxygen and perhaps a diluting gas, into the loop. There may be valves allowing venting of gas from the loop. A diver in a pool wearing an AGA full face mask A diver wearing an Ocean Reef full face mask A full-face diving mask is a type of diving mask worn by SCUBA divers so that they can talk with the surface or other divers. ... In order to meet Wikipedias quality standards, this article requires cleanup. ...


Most modern rebreathers have a twin hose mouthpiece or breathing mask where the direction of flow of gas through the loop is controlled by one-way valves. Some have a single pendulum hose, where the inhaled and exhaled gas passes through the same tube in opposite directions. The mouthpiece often has a valve letting the diver take the mouthpiece from the mouth while underwater or floating on the surface without water getting into the loop. Many rebreathers have "water traps" in the counterlungs, to stop large volumes of water from entering the loop if the diver removes the mouthpiece underwater without closing the valve, or if the diver's lips get slack letting water leak in.


Carbon dioxide scrubber

The exhaled gases are forced through the chemical scrubber which removes the carbon dioxide from the gas mixture and leaves the oxygen and other gases available for re-breathing[1]. The active ingredient of the scrubber is often soda lime. The carbon dioxide passing through the scrubber absorbent is removed when it reacts with the absorbent in the canister; this chemical reaction is exothermic. This reaction occurs along a "front" which is a cross section of the canister, of the unreacted soda lime that is exposed to carbon dioxide-laden gas. This front moves through the scrubber canister, from the gas input end to the gas output end, as the reaction consumes the active ingredients. However, this front would be a wide zone, because the carbon dioxide in the gas going through the canister needs time to reach the surface of a grain of absorbent, and then time to penetrate to the middle of each grain of absorbent as the outside of the grain becomes exhausted. In larger environments, such as recompression chambers, a fan is used to pass gas through the canister. // Soda lime is a mixture of chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent CO2 retention and carbon dioxide poisoning. ... In order to meet Wikipedias quality standards, this article requires cleanup. ... Vapours of hydrogen chloride in a beaker and ammonia in a test tube meet to form a cloud of a new substance, ammonium chloride A chemical reaction is a process that results in the interconversion of chemical substances. ... In thermodynamics, the word exothermic describes a process or reaction that releases energy in the form of heat. ...


Scrubber failure

The term "break through" means the failure of the "scrubber" to continue removing carbon dioxide from the exhaled gas mix. There are several ways that the scrubber may fail or become less efficient:

  • Complete consumption of the active ingredient ("break through").
  • The scrubber canister has been incorrectly packed or configured. This allows the exhaled gas to bypass the absorbent. In a rebreather, the soda lime must be packed tightly so that all exhaled gas comes into close contact with the granules of soda lime and the loop is designed to avoid any spaces or gaps between the soda lime and the loop walls that would let gas avoid contact with the adsorbent. If any of the seals, such as o rings, or spacers that prevent bypassing of the scrubber, are not cleaned or lubricated or fitted properly, the scrubber will be less efficient, or outside water or gas may get in circuit.
  • When the gas mix is under pressure caused by depth, the inside of the canister is more crowded by other gas molecules (oxygen or diluent) and the carbon dioxide molecules are not so free to move around to reach the absorbent. In deep diving with a nitrox or other gas-mixture rebreather, the scrubber needs to be bigger than is needed for a shallow-water or industrial oxygen rebreather, because of this effect. Among British naval rebreather divers, this type of carbon dioxide poisoning was called shallow water blackout.
  • A Caustic Cocktail - Soda lime is caustic and can cause burns to the eyes and skin. A "caustic cocktail" is a mixture of water and soda lime that occurs when the "scrubber" floods. It gives rise to a chalky taste, which should prompt the diver to switch to an alternative source of breathing gas and rinse his or her mouth out with water. Many modern diving rebreather absorbents are designed not to produce "cocktail" if they get wet.

Typical O-ring and application An O-ring is a loop of elastomer with a round (o-shaped) cross-section used as a mechanical seal or gasket. ... Nitrox refers to any gas mixture composed (excluding trace gases) of nitrogen and oxygen; this includes normal air which is approximately 78% nitrogen and 21% oxygen, with around 1% other gases. ... Hypercapnia is a condition where there is too much carbon dioxide (CO2) in the body. ... A shallow water blackout is a loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive in water typically shallower than five metres (16 feet), when the swimmer does not necessarily experience an urgent need to breathe and has no other obvious medical condition that... Look up caustic in Wiktionary, the free dictionary. ... Air is the most common and only natural breathing gas. ...

Failure prevention

  • An indicating dye in the soda lime. It changes the colour of the soda lime after the active ingredient is consumed. For example, a rebreather absorbent called "Protosorb" supplied by Siebe Gorman had a red dye, which was said to go white when the absorbent was exhausted. With a transparent canister, this may be able to show the position of the reaction "front". This is useful in dry open environments, but is not useful on diving equipment, where:
    • A transparent canister would likely be brittle and easily cracked by knocks.
    • Opening the canister to look inside would flood it with water or get unbreathable outside gas in circuit.
    • The canister is usually out of sight of the user, e.g. inside the breathing bag or inside a backpack box.
  • Temperature monitoring. As the reaction between carbon dioxide and soda lime is exothermic, temperature sensors, such as thermocouples along the length of the scrubber can be used to measure the position of the front and therefore the life of the scrubber. [1]
  • Diver training. Divers are trained to monitor and plan the exposure time of the soda lime in the scrubber and replace it within the recommended time limit. At present, there is no effective technology for detecting the end of the life of the scrubber or a dangerous increase in the concentration of carbon dioxide causing carbon dioxide poisoning. The diver must monitor the exposure of the scrubber and replace it when necessary.
  • Carbon dioxide gas sensors exist, but they are not sensitive enough to be used in a rebreather - the scrubber "break through" occurs quite suddenly and the diver shows symptoms before the sensor indicates a dangerous build-up of carbon dioxide. Even if a sensitive carbon dioxide sensor is developed, it may not be useful as the primary tool for monitoring scrubber life when underwater, because mixed gas rebreathers allow very long dives where long decompression stops may be needed: knowing that the rebreather will begin to deliver a poisonous breathing gas in five minutes may not be useful to a diver needing to carry out an hour or more of decompression stops.

Look up dye in Wiktionary, the free dictionary. ... Siebe Gorman Ltd was a British company which developed diving equipment and breathing equipment and worked on commercial diving and underwater salvage projects. ... In electronics, thermocouples are a widely used type of temperature sensor and can also be used as a means to convert thermal potential difference into electric potential difference. ... Hypercapnia is a condition where there is too much carbon dioxide (CO2) in the body. ... A Decompression Stop is a period of time a diver must spend at a constant depth in shallow water at the end of a dive in order safely to eliminate inert gases from the divers body to avoid decompression sickness. ... Air is the most common and only natural breathing gas. ...

Effectiveness

In rebreather diving, the typical effective duration of the scrubber will be half an hour to several hours of breathing, depending on the granularity and composition of the soda lime, the ambient temperature, the design of the rebreather, and the size of the canister. In some dry open environments, such as a recompression chamber or a hospital, it may be possible to put fresh absorbent in the canister when break through occurs.


Controlling the mix

A basic need with a rebreather is to keep the amount of oxygen in the mix, or more technically known as the partial pressure of oxygen or ppO2, from getting too low (causing anoxia or hypoxia) or too high (causing oxygen toxicity). In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. ... Asphyxia is a condition of severely deficient supply of oxygen to the body. ... Hypoxia is a pathological condition in which the body as a whole (generalised hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. ... Oxygen toxicity or oxygen toxicity syndrome is severe hyperoxia caused by breathing oxygen at elevated partial pressures. ...


With humans, the urge to breathe is caused by a build-up of carbon dioxide rather than lack of oxygen. When using a rebreather, carbon dioxide is removed from the breathing gas by the scrubber, suppressing this natural warning. The resulting serious hypoxia causes sudden blackout with little or no warning. This makes hypoxia a deadly problem for rebreather divers. Hypoxia is a pathological condition in which the body as a whole (generalised hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. ...


In many rebreathers the diver can control the gas mix and volume in the loop manually by injecting each of the different available gases to the loop and by venting the loop. The loop often has a pressure relief valve preventing the "hamster cheek" effect on the diver caused by over-pressure of the loop. Genera Mesocricetus Phodopus Cricetus Cricetulus Allocricetulus Cansumys Tscherskia Hamsters are rodents belonging to the subfamily Cricetinae. ...


In some early rebreathers the diver had to manually open and close the valve to the oxygen cylinder to refill the counter-lung each time. In others the oxygen flow is kept constant by a pressure-reducing flow valve like the valves on blowtorch cylinders; the set also has a manual on/off valve called a bypass. In some modern rebreathers, the pressure in the breathing bag controls the oxygen flow like the demand valve in open-circuit scuba; for example, trying to breathe in from an empty bag makes the cylinder release more gas. Most modern closed-circuit rebreathers have electro-galvanic fuel cell sensors and onboard electronics, which monitor the ppO2, injecting more oxygen if necessary or issuing an audible warning to the diver if the ppO2 reaches dangerously high or low levels. The word blowtorch can mean:- A cutting torch used for cutting metal. ... An electro-galvanic fuel cell is an electrical device used to measure the concentration of oxygen gas in SCUBA diving and medical equipment. ...


Counterlung

Underwater, the position of the breathing bag, on the chest, over the shoulders, or on the back, has an effect on the ease of breathing. The design of the rebreather also affects the swimming diver's streamlining and thus ease of swimming. Used most typically in competitive swimming, the streamline position is the position a swimmer takes underwater after pushing off a pool wall. ...


For use out of water, this does not matter so much: for example, in an industrial version of the Siebe Gorman Salvus the breathing bag hangs down by the left hip. CGI image: 2 views of a diver wearing a Siebe Gorman Salvus rebreather The Salvus is a light oxygen rebreather for industrial use (including by firemen and in coalmine rescue) or in shallow diving. ...


A rebreather whose counterlung is rubber and not in an enclosed casing, should be sheltered from sunlight when not in use, to prevent the rubber from perishing. This does not cite any references or sources. ... Prism splitting light High Resolution Solar Spectrum Sunlight in the broad sense is the total spectrum of the electromagnetic radiation given off by the Sun. ... Vulcanization refers to a specific curing process of rubber involving high heat and the addition of sulfur. ...


Bailout

Some diving rebreather sets include a bailout regulator allowing the user to bail onto open-circuit using his diluent tank. This lets the diver ascend on a separate gas supply. The majority of rebreather trainers teach students to also carry an open-circuit scuba cylinder and regulator as a separate bailout source. Bailout is a key area of discussion for rebreather diving, as when the depth starts to increase the bailout strategy becomes a crucial part of planning particularly for technical diving. Open circuit can mean: In electronics, where there is nothing connected to a load and no current can flow. ... Technical diving is a form of SCUBA diving that exceeds the scope of recreational diving. ...


Casing

Many rebreathers have their main parts in a hard backpack casing. This casing needs venting to let surrounding water or air in and out to allow for volume changes as the breathing bag inflates and deflates. In a diving rebreather this needs fairly large holes, including a hole at the bottom to drain the water out when the diver comes out of water. The SEFA, which is used for mine rescue, to keep grit and stones out of its working, is completely sealed, except for a large vent panel covered with metal mesh, and holes for the oxygen cylinder's on/off valve and the cylinder pressure gauge. Underwater the casing also serves for streamlining, e.g. in the IDA71 and Cis-Lunar. // The SEFA is a make of backpack industrial breathing set formerly made by Sabre Safety. ... Mine rescue is the specialized job of rescuing miners and others who have become trapped or injured in underground mines, often coalmines. ... A mesh is similar to fabric or a web in that it has many connected or weaved pieces. ... Used most typically in competitive swimming, the streamline position is the position a swimmer takes underwater after pushing off a pool wall. ... 3 views of a frogman with IDA rebreather The Russian IDA71 military and naval rebreather is an oxygen rebreather intended for use by naval and military divers. ... The word cis-lunar is Latin for on this side of the moon, not beyond the moon, and may refer to the scuba sets described here, or it may refer generically to space travel. ...


Main rebreather design variants

Oxygen rebreather

This is the oldest type of rebreather and was commonly used by navies from the early twentieth century. The only gas that it supplies is oxygen. As pure oxygen is toxic when inhaled at pressure, oxygen rebreathers are limited to a depth of 6 meters (20 feet); some say 9 meters (30 feet). Oxygen rebreathers are also sometimes used when decompressing from a deep open-circuit dive, as breathing pure oxygen makes the nitrogen diffuse out of the blood more rapidly. The multinational Combined Task Force One Five Zero (CTF-150) The British Grand Fleet, the supreme naval force of World War I A rare occurrence of a 5-country multinational fleet, during Operation Enduring Freedom in the Oman Sea. ... Oxygen toxicity or oxygen toxicity syndrome is severe hyperoxia caused by breathing oxygen at elevated partial pressures. ... A Decompression Stop is a period of time a diver must spend at a constant depth in shallow water at the end of a dive in order safely to eliminate inert gases from the divers body to avoid decompression sickness. ...


In some rebreathers, e.g. the Siebe Gorman Salvus, the oxygen cylinder has two first stages in parallel. One is constant flow; the other is a plain on-off valve called a bypass; both feed into the same exit pipe which feeds the breathing bag. In the Salvus there is no second stage and the gas is turned on and off at the cylinder. Some simple oxygen rebreathers had no constant-flow valve, but only the bypass, and the diver had to operate the valve at intervals to refill the breathing bag as he used the oxygen. CGI image: 2 views of a diver wearing a Siebe Gorman Salvus rebreather The Salvus is a light oxygen rebreather for industrial use (including by firemen and in coalmine rescue) or in shallow diving. ... A gas pressure regulator has one or more valves in series, which let the gas out of a gas cylinder in a controlled way, lowering its pressure at each stage. ... In rebreather breathing sets, a bypass is a hand-operated valve that can be used to let more oxygen (or other breathing gas) into the breathing system, by-passing the cylinders flow rate control valve. ... Inspiration Closed Circuit Diving Rebreather Description A rebreather is a type of breathing equipment that provides a breathing gas containing oxygen and recycles exhaled gas. ...


Semi-closed circuit rebreather

Military and recreational divers use these because they provide good underwater duration with fairly simple and cheap equipment. Semi-closed circuit equipment generally supplies one breathing gas such as air or nitrox or trimix. The gas is injected at a constant rate. Excess gas is constantly vented from the loop in small volumes. Nitrox refers to any gas mixture composed (excluding trace gases) of nitrogen and oxygen; this includes normal air which is approximately 78% nitrogen and 21% oxygen, with around 1% other gases. ... Trimix is a breathing gas, consisting of oxygen, helium and nitrogen, and is often used in deep commercial diving and during the deep phase of dives carried out using Technical diving techniques. ...


The diver must fill the cylinders with gas mix that has a maximum operating depth that is safe for the depth of the dive being planned. As the amount of oxygen required by the diver increases with work rate, the oxygen injection rate must be carefully chosen and controlled to prevent either oxygen toxicity or unconsciousness in the diver due to hypoxia. In technical diving, the maximum operating depth (MOD) of a breathing gas is the depth at which the partial pressure of oxygen (ppO2) of the gas mix exceeds a safe limit. ... Oxygen toxicity or oxygen toxicity syndrome is severe hyperoxia caused by breathing oxygen at elevated partial pressures. ... Unconsciousness is the absence of consciousness. ... Hypoxia may refer to: Hypoxia (medical), the lack of oxygen in tissues Hypoxia or Oxygen depletion, a reduced concentration of dissolved oxygen in a water body leading to stress or even death in aquatic organisms This is a disambiguation page: a list of articles associated with the same title. ...


Fully closed circuit rebreather

Military, photographic and recreational divers use these because they allow long dives and produce no bubbles. Closed circuit rebreathers generally supply two breathing gases to the loop: one is pure oxygen and the other is a diluent or diluting gas such as air, nitrox or trimix.


The major task of the fully closed circuit rebreather is to control the oxygen concentration, known as the oxygen partial pressure, in the loop and to warn the diver if it is becoming dangerously low or high. The concentration of oxygen in the loop depends on two factors: depth and the proportion of oxygen in the mix. Too low a concentration of oxygen results in hypoxia leading to sudden unconsciousness and ultimately death when the oxygen is exhausted. Too high a concentration of oxygen results in oxygen toxicity, a condition causing convulsions, which make the diver spit his regulator out when they occur underwater and can lead to drowning. In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. ... This article or section does not adequately cite its references or sources. ...


In fully automatic closed-circuit systems, a mechanism injects oxygen into the loop when it detects that the partial pressure of oxygen in the loop has fallen below the required level. Often this mechanism is electrical and relies on oxygen sensitive electro-galvanic fuel cells called ppO2 meters to measure the concentration of oxygen in the loop. The article on electrical energy is located elsewhere. ... An electro-galvanic fuel cell is an electrical device used to measure the concentration of oxygen gas in SCUBA diving and medical equipment. ... A diving breathing gas oxygen analyser consisting of the cylindrical fuel cell connected to the display and calibration box An electro-galvanic fuel cell is an electrical device used to measure the concentration of oxygen gas in scuba diving and medical equipment. ...


The diver may be able to manually control the mixture by adding diluent gas or oxygen. Adding diluent can prevent the loop's gas mixture becoming too oxygen rich. Manually adding oxygen is risky as additional small volumes of oxygen in the loop can easily raise the partial pressure of oxygen to dangerous levels.


Rebreathers whose absorbent releases oxygen

There have been a few rebreather designs (e.g. the Oxylite) which had an absorbent canister filled with potassium superoxide, which gives off oxygen as it absorbs carbon dioxide: 4KO2 + 2CO2 = 2K2CO3 + 3O2; it had a very small oxygen cylinder to fill the loop at the start of the dive. This system is dangerous because of the explosively hot reaction that happens if water gets on the potassium superoxide. The Russian IDA71 military and naval rebreather was designed to be run in this mode or as an ordinary rebreather. 3 views of a frogman with IDA rebreather The Russian IDA71 military and naval rebreather is an oxygen rebreather intended for use by naval and military divers. ...


Rebreathers which store their oxygen as liquid oxygen

Aerorlox rebreather in a coalmining museum
Aerorlox rebreather in a coalmining museum

If used underwater, the liquid-oxygen tank must be well insulated against heat coming in from the water. As a result, industrial sets of this type may not be suitable for diving, and diving sets of this type may not be suitable for use out of water. They include these types: Image File history File links Download high-resolution version (570x740, 52 KB) An Aerorlox industrial oxygen rebreather in a coal mining museum I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version... Image File history File links Download high-resolution version (570x740, 52 KB) An Aerorlox industrial oxygen rebreather in a coal mining museum I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version...

An Aerophor in a coal mining museum The Blacketts Aerophor is a nitrox semi-closed-circuit rebreather with liquid gas storage made in England from 1910 onwards for use in mine rescue and other industrial uses. ...

Cryogenic rebreather

There have been plans for a "cryogenic rebreather". It has a tank of liquid oxygen and no absorbent canister. The carbon dioxide is frozen out in a "snow box" by the cold produced as the liquid oxygen expands to gas as the oxygen is used and is replaced from the oxygen tank.


Such a rebreather called the S-1000 was built around or soon after 1960 by Sub-Marine Systems Corporation. It had a duration of 6 hours and a maximum dive depth of 200 meters of salt water. Its ppO2 could be set to anything from 0.2 bar to 2 bar without electronics, by controlling the temperature of the liquid oxygen, thus controlling the equilibrium pressure of oxygen gas above the liquid. The diluent could be either liquid nitrogen or helium depending on the depth of the dive. The set could freeze out 230 grams of carbon dioxide per hour from the loop, corresponding to an oxygen consumption of 2 liters per minute. If oxygen was consumed faster (high workload), a regular scrubber was needed. See: General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... In order to meet Wikipedias quality standards, this article requires cleanup. ...

  • Fischel H., Closed circuit cryogenic SCUBA, "Equipment for the working diver" 1970 symposium, Washington, DC, USA. Marine Technology Society 1970:229-244.
  • Cushman, L., Cryogenic Rebreather, Skin Diver magazine, June 1969, and reprinted in Aqua Corps magazine, N7, 28, 79.

There are articles on the web about a cryogenic rebreather called Titanic II. These articles are a hoax; some of them include unrealistic technology. A hoax is an attempt to trick an audience into believing that something false is real. ... Unobtainium is a colloquial term, collectively describing rare, costly, or physically impossible materials that are needed for a given application. ...


Other designs

  • In the Siebe Gorman Proto the absorbent was in a flexible-walled compartment in the bottom of the breathing bag and not in a canister.
  • This link describes an experimental drysuit (with built-in hood and fullface mask) and rebreather combination where the drysuit acts as the breathing bag, like in an old Draeger standard diving suit variant which had a rebreather pack attached.
  • Some British naval rebreathers (e.g. the Siebe Gorman CDBA) had a backpack weight pouch instead of the diver having a separate weight belt.

The Proto is a type of rebreather that was made by Siebe Gorman. ... drysuits are used in a number of sports to provide a barrier between the occupant and cold water. ... Inspiration Closed Circuit Diving Rebreather Description A rebreather is a type of breathing equipment that provides a breathing gas containing oxygen and recycles exhaled gas. ... Dräger is a big German firm who makes diving gear. ... A standard diving dress consists of a copper, brass or bronze diving helmet, an umbilical cord leading to a surface supplied diving air pump, a canvas diving suit and lead boots. ... The Siebe Gorman CDBA from three angles The Clearance Divers Breathing Apparatus (CDBA) is a type of rebreather made by Siebe Gorman in England. ... A bag weight belt and a traditional weight belt Divers wear weighting systems, weight belts or weights, generally made of lead, to counteract the buoyancy of other diving equipment, such as diving suits and aluminium diving cylinders. ...

Risks and precautions with rebreather diving

Many diver training organizations teach the "diluent flush" technique as a safe way to restore the mix in the loop to a level of oxygen that is neither too high nor too low. It only works when partial pressure of oxygen in the diluent alone would not cause hypoxia or hyperoxia, such as when using a normoxic diluent and observing the diluent's maximum operating depth. The technique involves simultaneously venting the loop and injecting diluent. This flushes out the old mix and replaces it with a known proportion of oxygen from the diluent. This page lists SCUBA diver training organizations. ... In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. ... Hypoxia is a pathological condition in which the body as a whole (generalised hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. ... Wikipedia does not have an article with this exact name. ... Trimix is a breathing gas, consisting of oxygen, helium and nitrogen, and is often used during the deep phase of dives carried out using Technical diving techniques. ... In technical diving, the maximum operating depth (MOD) of a breathing gas is the depth at which the partial pressure of oxygen (ppO2) of the gas mix exceeds a safe limit. ...


Divers using oxygen rebreathers are advised to flush the system when they start the dive, to get surplus nitrogen out of the system.


In addition to the other diving disorders suffered by divers, rebreather divers are also more susceptible to: Divers face specific physical and health risks when they go underwater (e. ...

  • Sudden blackout due to hypoxia caused by too low a partial pressure of oxygen in the loop. A particular problem when using a closed circuit rebreather is the drop in ambient pressure caused by the ascent phase of the dive, which reduces the partial pressure of oxygen to hypoxic levels leading to what is sometimes called deep water blackout.
  • Seizures due to oxygen toxicity caused by too high a partial pressure of oxygen in the loop. This can be caused by the rise in ambient pressure caused by the descent phase of the dive, which raises the partial pressure of oxygen to hyperoxic levels. In fully closed circuit equipment, aging oxygen sensors may become "current limited" and fail to measure high partial pressures of oxygen resulting in dangerously high oxygen levels.
  • Disorientation, panic, headache, and hyperventilation due to excess of carbon dioxide caused by incorrect configuration, failure or inefficiency of the scrubber. The scrubber must be configured so that no exhaled gas can bypass it; it must be packed and sealed correctly. Another problem is the diver producing carbon dioxide faster than the absorbent can handle, for example, during hard work or fast swimming. The solution to this is to slow down and let the absorbent catch up. The scrubber efficiency may be reduced at depth where the increased concentration of other gas molecules, due to pressure, stops all the carbon dioxide molecules reaching the active ingredient of the scrubber.
  • The rebreather diver must keep breathing in and out all the time, to keep the exhaled gas flowing over the carbon dioxide absorbent, so the absorbent can work all the time. Divers need to lose any air conservation habits that may have been developed while diving with open-circuit scuba. In closed circuit rebreathers, this also has the advantage of mixing the gases preventing oxygen-rich and oxygen-lean spaces developing within the loop, which may give inaccurate readings to the oxygen control system.
  • "Caustic cocktail" in the loop if water comes into contact with the soda lime used in the carbon dioxide scrubber. The diver is normally alerted to this by a chalky taste in the mouth. A safe response is to bail out to "open circuit" and rinse the mouth out.

When compared with Aqua-Lungs, rebreathers have some disadvantages including expense, complexity of operation and maintenance and fewer failsafes. A malfunctioning rebreather can supply a gas mixture which cannot sustain life. Various rebreathers try to solve these problems by monitoring the system with electronics, sensors and alarm systems. Many very competent divers have died using rebreathers in accidents, which are often put down to operator error. Rebreathers are generally considered safer in extreme conditions such as deep dives (75m = 246 feet or more) or overhead environments, as they reduce the risk of running out of breathable gas. In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. ... Latent hypoxia hits on ascent A deep water blackout is a loss of consciousness caused by cerebral hypoxia on ascending from a deep freedive or breath-hold dive, typically of ten metres or more when the swimmer does not necessarily experience an urgent need to breathe and has no other... This article is about epileptic seizures. ... Oxygen toxicity or oxygen toxicity syndrome is severe hyperoxia caused by breathing oxygen at elevated partial pressures. ... An electro-galvanic fuel cell is an electrical device used to measure the concentration of oxygen gas in SCUBA diving and medical equipment. ... Panic is the primal urge to run and hide in the face of imminent danger. ... A headache (cephalalgia in medical terminology) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... In medicine, hyperventilation (or hyperpnea) is the state of breathing faster or deeper (hyper) than necessary, and thereby reducing the carbon dioxide concentration of the blood below normal. ... // Hypercapnia (from the Greek hyper = above and kapnos = smoke), also known as CO2 Poisoning, is a condition where there is too much carbon dioxide (CO2) in the blood. ... // Soda lime is a mixture of chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent CO2 retention and carbon dioxide poisoning. ... Open circuit can mean: In electronics, where there is nothing connected to a load and no current can flow. ... // Soda lime is a mixture of chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent CO2 retention and carbon dioxide poisoning. ... In order to meet Wikipedias quality standards, this article requires cleanup. ... ... The term Fail-safe is used to describe: A device which, if (or when) it fails, fails in a way that will cause no harm or at least a minimum of harm to other devices or danger to personnel. ... In scuba diving, an Overhead environment is a situation where there is not open water overhead, and thus the diver in an emergency cannot escape upwards to atmosphere if his breathing set malfunctions. ...


The bailout requirement of rebreather diving can sometimes also require a rebreather diver to carry almost as much bulk of cylinders as an open-circuit diver so the diver can complete the necessary decompression stops if the rebreather fails completely. Some rebreather divers prefer not to carry enough bailout for a safe ascent breathing open circuit, but instead rely on the rebreather, believing that an irrecoverable rebreather failure is very unlikely. This practice is known as alpinism or alpinist diving and is generally maligned due to the perceived extremely high risk of death if the rebreather fails. This article is about the breathing apparatus. ... 12 litre and 3 litre steel diving cylinders A diving cylinder, scuba tank or diving tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ... A Decompression Stop is a period of time a diver must spend at a constant depth in shallow water at the end of a dive in order safely to eliminate inert gases from the divers body to avoid decompression sickness. ...


Some makes of rebreather

The Davis Submerged Escape Apparatus (also referred to as DSEA), is an early make of oxygen rebreather invented in 1910 by Sir Robert Davis, head of Messrs. ... The Davis Submerged Escape Apparatus (also referred to as DSEA), is an early make of oxygen rebreather invented in 1910 by Sir Robert Davis, head of Messrs. ... The Sladen Suit was a heavy type of British divers drysuit made by Siebe Gorman. ... 3 views of a frogman with IDA rebreather The Russian IDA71 military and naval rebreather is an oxygen rebreather intended for use by naval and military divers. ... The Siebe Gorman CDBA from three angles The Clearance Divers Breathing Apparatus (CDBA) is a type of rebreather made by Siebe Gorman in England. ... CGI image: 2 views of a diver wearing a Siebe Gorman Salvus rebreather The Salvus is a light oxygen rebreather for industrial use (including by firemen and in coalmine rescue) or in shallow diving. ... Siebe Gorman Ltd was a British company which developed diving equipment and breathing equipment and worked on commercial diving and underwater salvage projects. ... Image File history File links Aa_savox1. ... The Blacketts Aerophor is a nitrox semi-closed-circuit rebreather with liquid gas storage made in England from 1910 onwards for use in mine rescue and other industrial uses. ... Nitrox refers to any gas mixture composed (excluding trace gases) of nitrogen and oxygen; this includes normal air which is approximately 78% nitrogen and 21% oxygen, with around 1% other gases. ... Chuquicamata, the second largest open pit copper mine in the world, Chile. ... // The SEFA is a make of backpack industrial breathing set formerly made by Sabre Safety. ... The SDBA is a type of frogmans rebreather breathing set. ... Nitrox refers to any gas mixture composed (excluding trace gases) of nitrogen and oxygen; this includes normal air which is approximately 78% nitrogen and 21% oxygen, with around 1% other gases. ... // This page describes a type of scuba diver. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ...

External links

Image File history File links Nuvola_apps_important. ...

Other information sources

A hot water bottle is a rubber container that you can use to keep your feet warm at night. ...

Surface-only (industrial) rebreather manufacturers

(see SCBA) SCBA is an acronym for Self Contained Breathing Apparatus. ...

  • BioPak 240R Revolution - claim to make a 4-hour-duration rebreather

Diving rebreather manufacturers

  • Ambient Pressure Diving - maker of the Inspiration and Evolution rebreathers.
  • Analytical Industries - manufacturer of oxygen sensors for rebreathers.
  • Carleton Life Support Technologies - manufacturer of the VIPER and SIVA military rebreathers.
  • CCR2000 for CCR2000 rebreathers.
  • Cis-Lunar - made closed-circuit automatic rebreathers, now operated by Juergensen Marine.
  • Closed Circuit Research Ltd - manufacturer of the Ouroboros rebreather.
  • Divematics - maker of the Shadow Pac II rebreather.
  • Dive Rite - technical SCUBA gear pioneer established in 1984. Manufacturer of the O2ptima FX closed circuit rebreather.
  • Divex Ltd - manufacturer of several military semi-closed and closed circuit rebreathers.
  • Draeger Safety - maker of various semi-closed circuit rebreathers.
  • Halcyon - maker of a semi-closed circuit rebreather.
  • Jetsam - maker of the KISS rebreather.
  • Laguna Research Inc. manufacturer of rebreather controller and monitoring systems.
  • Megalodon & Mini Meg - The Megalodon Expedition class rebreather.
  • O.M.G. Italy - manufacturer of the AZIMUTH and many military rebreathers.
  • Rebreatherlab - Manufacturers of the Pelagian rebreather.
  • Rebreather US - The Juergensen Marine Hammerhead Electronic System.
  • Rebreathers Australia - maker of the Abyss and Stingray closed circuit rebreathers.
  • Siebe Gorman, see also Siebe Gorman. Important in diving history, but now closed down.
  • Shearwater Research - Rebreather monitors, controllers, and computers.
  • Steam Machines - Prism rebreathers.
  • Submatix Rebreather - manufacturer of the Submatix SCR 100 ST.
  • Subsea Systems - manufacturer of rebreather electronics.
  • Teledyne Analytical Instruments - manufacturer of oxygen sensors for rebreathers.

The word cis-lunar is Latin for on this side of the moon, not beyond the moon, and may refer to the scuba sets described here, or it may refer generically to space travel. ... Siebe Gorman Ltd was a British company which developed diving equipment and breathing equipment and worked on commercial diving and underwater salvage projects. ...

References

  1. ^ a b c d Reynolds, Glen Harlan (2006), "Seeking New Depths", Popular Mechanics 183(12): 58, ISSN 0032-4558

  Results from FactBites:
 
RB (3493 words)
With rebreathers, however, the breathing gas may be dynamic, and thus the oxygen concentration may drift out of life-sustaining range within the course of a single dive.
In the case of oxygen rebreathers, if the breathing loop is not adequately flushed prior to commencing the dive, the fraction of nitrogen in the breathing gas may be high.
For oxygen rebreathers with passive-addition oxygen control systems, it is possible that the diver may breathe-up all of the oxygen in the breathing loop before the oxygen addition valve is triggered, thus leaving only nitrogen.
closed circuit rebreathers, parts and training (143 words)
We are a company who design and manufacture closed circuit rebreathers, parts and accessories with the focal point on simplicity, durability and user friendliness.
Behind every rebreather part lies hundreds of hours of thinking, designing, prototyping, testing and diving.
Non of this is intended to be used as reference or to replace a proper closed circuit rebreather training course.
  More results at FactBites »

 
 

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