USN Testing Perspective Rebreather divers must overcome the work of breathing due to breathing resistance, static lung load, and elastance. Inspired CO2 amplifies these effects by increasing ventilation. CO2 sensors and scrubber gauges would decrease this risk. CO2 canister duration is tested as a function of temperature, workload, and depth. O2 control accuracy is assessed. Testing should be performed on breathing machines and by divers. What is the role of failure mode effect and criticality analysis (FMECA) in rebreather design? New U.S. Navy performance standards are based on diver tolerance. U.S. Navy and EU rebreather test standards should not differ, but do. Powerpoint Show Video Presentation (MP4)

Diving re-breathing apparatus: Testing and standards, UK/EU Perspective What is the European Union (EU) CE mark and how do you get it? The principles and physiological basis for the testing required by the harmonised standard (EN 14143) are presented and discussed including: manned and unmanned UK test procedures for rebreathers; performance parameters and standards; work of breathing, peak to end pressure, O2 and CO2 control; hydrostatic imbalance, breathing bag location, and diver position; and gas density and end-tidal CO2. Powerpoint Show Video Presentation (MP4)

Rebreather Incident Investigation NEDU has had a long history of investigating rebreather accidents. Compared to open circuit, rebreathers can kill without leaving evidence. Navy investigations on analog electronic UBA (MK 16) and digital, computer controlled UBA (EX 19) are discussed. The lack of information on oxygen control and alarm algorithms for computer controlled UBA is a concern. A dive data recorder would be valuable for investigating diving accidents. Characteristics that a forensic investigative team needs are listed. Powerpoint Show Video Presentation (MP4)

Manufacturers Panel Nawrocky, Parker, Readey, Stone, Deas, Haynes, Melton, Jablonski, Scamahorn Topics discussed included: pros & cons of closed-circuit and semi-closed circuit rebreathers; rebreather failure analysis; recreational rebreathers testing; design standardization; automatic diluent add valves; manual O2 add valves; electronic O2 control and sensor calibration; CO2 canister testing; bail-out procedures; full-face mask & communications; incident investigation; training standards & rentals; and rebreather technology future. Powerpoint Show Video Presentation (MP4)