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TDI Evolution Closed Circuit Rebreather Diver Course by BorneoDream.com

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Title: TDI Evolution Closed Circuit Rebreather Diver Course by BorneoDream.com


1
TDI Evolution Closed Circuit Rebreather Diver
Course byBorneoDream.com
Billy Hammond 10407 - 2007
2
Overview of Course Structure
TDI Inspiration and Evolution Closed Circuit
Rebreather Diver Course
  • 1 - Introduction and Welcome
  • 2 - The History and Development of Rebreathers
  • 3 - Mechanics of the inspiration and Evolution
  • 4 - Classic Electronics Control (Optional)
  • 5 - Vision Electronics Control (Optional)
  • 6 - Physiology - A Reflection for the CCR Diver

3
Overview of Course Structure continued
TDI Inspiration and Evolution Closed Circuit
Rebreather Diver Course
  • 7 - Lets Go Diving the Rebreather - Preparation
  • 8 - Lets Go Diving the Rebreather - In the Water
  • 9 - Avoiding Rebreather Incidents - Safe Diving
  • 10 - Mod 2 Extension (Optional extra course)
  • 11 - Mod 3 Extension (optional extra course)

4
TDI Inspiration/Evolution Family of Rebreathers
Divers Course
  • Section 1
  • Introduction and Welcome

5
Introduction and Welcome
  • Congratulations of enrolling in a most thrilling
    experience with Inspiration/Evolution technology
  • Welcome to a new way of thinking about diving
  • Understand that you are ALL novices again
  • You will develop new skills for CCR diving
    including
  • Attitudes
  • Disciplines
  • Awareness

6
Introduction and Welcome
  • Who the course is for and what you can expect to
    get out of it.
  • COURSE PREREQUISITES
  • 18 years of age
  • Logged 100 dives
  • Nitrox and Advanced Nitrox training
  • COURSE CREDENTIALS
  • To become qualified to dive the
    Inspiration/Evolution family of rebreathers on
    either Classic or Vision Electronics or both
    (double certification and extra dives) on Air
    Diluent up to 40m/132ft with safety stops and 5
    minutes max deco at 6m/ 20ft

7
Introduction and Welcome
  • Why CCR Diving
  • Longer dive durations possible with very little
    equipment
  • Almost silent and bubble free unless ascending
  • Extremely efficient use of breathing gas
  • Optional Nitrox mix for all depths according to
    user-selectable PPO2 setpoint
  • Warm and moist comfortable breathing gas reducing
    risk of hypothermic tendencies

8
Introduction and Welcome
  • What else can you expect to experience on this
    course?
  • Many new terms for CCR not used in OC or SCR
    diving
  • Change from a constant percentage Nitrox mix in
    OC to a variable percentage Nitrox mix with
    constant partial pressure in CCR mode
  • Computer controlled gas injection system on
    ascent causes accelerating bouyancy
    characteristics
  • We need to think differently
  • Jump a billion years of evolutionary development
  • An opportunity to almost evolve into a sea-going
    mammal with hours of sub-surface capability, and
    be back on land again for another fun filled
    experience

9
TDI Inspiration/Evolution Family of Rebreathers
Divers Course
  • Section 2
  • The History and
  • Development of Rebreathers

10
The History and Development of Rebreathers
  • Rebreathers in basic form have been around for
    over a century underwater, and longer for mine
    rescue work
  • The earliest makes were pure oxygen devices
  • The Englishmen Henry Fleuss achieves a major
    milestone covering over 300 meters (1000 feet)
    underwater in the construction of the Severn
    railway tunnel a century ago
  • Military rebreathers developed and used-Stealth

11
The History and Development of Rebreathers
  • The advent of readily available Nitrox to the
    recreational market fuelled the development of
    recreational nitrox SCR rebreathers
  • Progress and need in the military theater saw the
    development of a number of electronic controlled
    CCR machines over the last two decades
  • Some cave divers opted for passive mechanical SCR
    with
  • no electronics
  • Makes include the Electrolung Cis Lunar Drager
    Atlantis, Dolphin and Ray.
  • We see the advent of recreational CCRs with the
    Inspiration in 1997, followed by Prism,
    Megalodon, Ouroboros, Optima and Kiss, and in
    2005 the Evolution

12
The History and Development of Rebreathers
  • CONCEPTUAL REBREATHER DESIGN
  • All need a scrubber for CO2 removal
  • Pure Oxygen rebreather no need for electronics
    in basic form just keep manually adding gas when
    loop volume falls
  • Semi Closed SCR uses a known nitrox for loop
    addition
  • Mechanical rebreathers use a fractional volume
    technique to refresh gas
  • Either Passive by sucking in fresh gas when
    oxygen in the loop volume is depleted and a
    diaphragm regulator re-injects to bring loop
    volume back up, or
  • Active Constant flow rate of Nitrox to
    loop-vent excess

13
The History and Development of Rebreathers
  • INSPIRATION AND EVOLUTION
  • Closed Circuit rebreathers (CCR)
  • State of the art electronic controls
  • Onboard sources of air and oxygen, scrubber,
    computer controlled variable Nitrox mixing
  • Everything the recreational and technical diver
    needs

14
TDI Inspiration/Evolution Family of Rebreathers
Divers Course
  • Section 3
  • Mechanics and basic functioning
  • of the Inspiration and Evolution rebreather
    systems

15
Mechanics and basic functioning of the
Inspiration and Evolution
  • Divers Lungs
  • Mouthpiece and Hoses
  • Exhalation Counterlung
  • Manual Inject Buttons
  • Over Pressure Release Valve
  • The Scrubber
  • The Scrubber Cartridge
  • The Lid and handsets
  • Three Independent Oxygen Sensors
  • The Handsets and Gas Control
  • Battery Compartment
  • Warning Buzzer
  • Cell Connectors
  • The Oxygen Supply
  • Inhalation Counterlung
  • Diluent Gas Supply

16
Mechanics and basic functioning of the
Inspiration and Evolution
  • Including Optional System Components
  • Auto-Diluent Additional Valve (ADV) and inline LP
    Flow Stop control device
  • Vision Electronics System (Factory Purchase)
  • Includes a redundant LED head-up Display (HUD).
    Standard on the Evolution, the Vision package is
    optional on the Inspiration.
  • Optional Scrubber monitoring temperature sensing
  • Stick

17
Mechanics and basic functioning of the
Inspiration and Evolution
  • DIVERS LUNGS
  • The motor that powers the gas around the
    rebreather gas loop
  • The point of exchange for O2 rich gas to the body
    and CO2 rich gas from the body
  • When we inhale, clean O2 rich gas comes in from
    the left.
  • The flow is from the divers lungs through the
    mouthpiece to the right

18
Mechanics and basic functioning of the
Inspiration and Evolution
  • MOUTHPIECE and HOSES
  • Mouthpiece and one-way mushroom valves control
    direction of gas flow
  • Timing of gas flow is in sympathy with divers
    breathing pattern.
  • Hoses are large bore. This reduces the work of
    breathing (WOB)
  • Mouthpiece hose is weighted for dynamic balance -
    adjustable

19
Mechanics and basic functioning of the
Inspiration and Evolution
  • EXHALATION COUNTERLUNG
  • Counterlungs come from the factory in 4 different
    sizes User Selectable
  • Contains first fixed T-piece and water-trap
    flow valve directing gas and water into the
    exhalation counterlung
  • Flexible breathing bag to contain gas from body
  • Contains both the Manual Oxygen Addition Valve
    and the Gas Loop Over Pressure Release Valve

20
Mechanics and basic functioning of the
Inspiration and Evolution
  • THE CO2 SCRUBBER (or Stack)
  • Gas path is from the exhalation counterlung,
    through the T-piece down to the bottom of the CO2
    scrubber
  • It fans out to a large bore axial flow through
    the scrubber to reduce gas velocity and increase
    Dwell Time for CO2 removal

21
Mechanics and basic functioning of the
Inspiration and Evolution
  • THE SCRUBBER CARTRIDGE
  • Designed to remove CO2 from the gas loop.
  • Spring loaded to maintain air gap at bottom
  • Designed with Hydrophobic membranes for
    prevention of water absorption
  • Contains upper and lower plastic retainers for
    the scrubber material

22
Mechanics and basic functioning of the
Inspiration and Evolution
  • The Scrubber Cartridge continued
  • Different scrubber makes can give different
    duration times due to different granule sizes
  • Spacer and o-ring for prevention of gas by-pass
    up the side of the scrubber canister
  • Only designed to remove CO2, not any other toxic
    compounds or contaminants in the breathing gas

23
Mechanics and basic functioning of the
Inspiration and Evolution
  • SCRUBBER MATERIALS
  • Have a defined shelf life time and in use up to 3
    hours
  • Effectiveness altered by time, temperature and
    moisture
  • Sofnolime 797 grade recommended ( Other makes
    include Dragersorb and Sodasorb)
  • Sofnolime is primarily a Sodium Hydroxide
    compound
  • Needs proper packing to prevent CO2 channeling
  • Efficiency is reduced by high gas flow rates
    (fast or skip breathing) or focused channeling
    characteristics
  • In a properly assembled and properly functioning
    CCR system the CO2 scrubber is the Achilles
    Heel

24
Mechanics and basic functioning of the
Inspiration and Evolution
  • SCRUBBER MANAGEMENT
  • No partial filling of the scrubber. New full
    canister every time
  • Do not empty scrubber into a bag and re-pack the
    scrubber later- new and used granules are then
    mixed
  • Do not store partly used scrubber for more than a
    few days. The material absorbs CO2 and grows mold

25
Mechanics and basic functioning of the
Inspiration and Evolution
  • CONTROLLERS
  • GENERAL
  • Power On
  • No wet contacts
  • Switch on manually
  • Self testing electronics. Hear/see alarms and
    hear solenoid firing
  • 3 control buttons, but classic uses a separate
    power switch also

26
Mechanics and basic functioning of the
Inspiration and Evolution
  • HANDSET CONTROLLER GENERALITIES
  • Handset controllers are electronic handle
    carefully
  • There are two independent handset controllers
    on all Inspirations/Evolutions
  • The primary function of the controller is to
    control oxygen injection and display real time
    information to the diver
  • The controller also drives the alarm systems and
    interfaces with the diver via 3 control buttons
  • Can be switched on and off separately
  • They are redundant in a Master/Slave combination
  • Either controller can be the Master

27
Mechanics and basic functioning of the
Inspiration and Evolution
  • CONTROLLER LOCATIONS
  • On the Inspiration Classic the controllers are in
    the handsets
  • On Vision Electronics the single handset is a
    display and keypad only the controllers are in
    the Scrubber Lid

28
Mechanics and basic functioning of the
Inspiration and Evolution
  • THE SCRUBBER LID and HANDSETS
  • The electronic brains of the device
  • Function is to control the PPO2 of the breathing
    gas to a user defined setpoint and display this
    and other dive parameters to the diver visually
    (handset display) (and HUD on Vision) and audibly
    (buzzer alarms)
  • Great care should be taken when handling them
  • For transport fully assemble rebreather or carry
    lid and handsets separately in a padded bag
  • Treat it with the same care as a laptop

29
Mechanics and basic functioning of the
Inspiration and Evolution
  • 3 INDEPENDENT OXYGEN SENSORS
  • 3 galvanic fuel cells each with a milli-volt
    output proportional to the oxygen exposure across
    their outer faces (breathing gas)
  • Voting logic of the computer for oxygen control
    purposes averages the nearest 2 readings and
    ignores the 3rd
  • This information is displayed to the diver as
    PPO2 values
  • Delicate pin connections
  • Should never smell of toxic or other vapors

30
Mechanics and basic functioning of the
Inspiration and Evolution
  • THE HANDSETS ( and HUD on Vision)
  • Redundant controller PPO2 readings displayed to
    the diver
  • Inspiration has 2 handsets, Evolution has 1
    handset
  • Provide for underwater dive menu changes to suit
    environment
  • Must be switched on to have a chance to drive the
    oxygen solenoid
  • Will give indications of battery health,
    controller health, and cell health in real time,
    underwater
  • Can drive audible and visual alarms
  • Redundancy so that 1 controller can fail while
    the other allows you to safely exit the water
  • Need to constantly be checking PPO2 on the handset

31
Mechanics and basic functioning of the
Inspiration and Evolution
  • THE HANDSETS (and HUD on VISION) continued
  • Can drive audible and visual alarms
  • Redundancy so that 1 controller can fail while
    the other allows you to safely control the
    rebreather and exit the water
  • Need to constantly be checking the PPO2 on the
    handset during the dive

32
Mechanics and basic functioning of the
Inspiration and Evolution
  • CONSTANT PPO2 GAS CONTROL
  • Remember Daltons Law from Advanced Nitrox
    Pressure gas FO2 x Pressure
  • At different depths (gas pressures) for a
    constant PPO2 controller setting we will have a
    Nitrox mix that changes proportionally to
    pressure
  • At any given depth we can calculate the Nitrox
    mix for any given PPO2 setting

33
Mechanics and basic functioning of the
Inspiration and Evolution
34
Mechanics and basic functioning of the
Inspiration and Evolution
  • BATTERY COMPARTMENT
  • Two slots for the two 2CR-P2 lithium 6 volt
    batteries
  • Battery life typically 15 20 hours for the
    master
  • Slave battery life longer not firing the
    solenoid

35
Mechanics and basic functioning of the
Inspiration and Evolution
  • WARNING BUZZER (and HUD)
  • Connected to the scrubber lid but normally fed to
    the T-piece by divers left ear (HUD goes same
    way to left side of mouthpiece)
  • This is a secondary warning device, the handsets
    are the primary indicators always
  • In conditions of low battery power alarms may
    fail before handsets do
  • (The HUD provides green/red visual health status
    to the divers direct area of vision)

36
Mechanics and basic functioning of the
Inspiration and Evolution
  • CELL CONNECTORS
  • These are delicate and covered with red or blue
    moisture caps with holes for pressure
    equalization
  • Take great care not to damage wires or connectors
    if changing cells

37
Mechanics and basic functioning of the
Inspiration and Evolution
  • THE OXYGEN SUPPLY
  • Dive tank switched on
  • HP to SPG on front of exhalation lung gives O2
    pressure
  • LP hose feeds O2 to the LID for the solenoid
    from the first stage regulator
  • First stage regulator I/P must be 7.5 Bar
  • Evolution uses 2 liter cylinders, Inspiration
    uses 3 liter cylinders
  • Remember- Rich mix Right, Lean mix Left

38
Mechanics and basic functioning of the
Inspiration and Evolution
  • INHALATION COUNTERLUNG
  • O2 rich gas from the scrubber lid comes up to the
    inhalation counterlung
  • Blue color coded for hoses containing clean
    oxygenated gas with the CO2 removed
  • Passes through the inhalation T-piece without
    Water-Traps on the newer machines
  • Blue Manual Diluent addition button at bottom of
    inhalation counterlung

39
Mechanics and basic functioning of the
Inspiration and Evolution
  • DILUENT GAS SUPPLY
  • Need to use diluent below 6msw (20fsw)
  • Manually add diluent on descent depressing the
    blue manual addition button on the inhalation
    counterlung to equalize the loop volume with
    pressure changes
  • LP feeds both the wing BCD and the Auto-air OC
    bailout device
  • Tank pressure is displayed on the SPG via HP hose
    over left shoulder
  • Do not use for Drysuit inflation use off board
    gas
  • IP normally set to 9.5 Bar

40
Mechanics and basic functioning of the
Inspiration and Evolution
  • OPTIONAL AUTO-ADDITION DILUENT VALVE ADV and
    FLOW STOP CONTROL DEVICE
  • Replaces Inhalation T-piece and does not contain
    a water-trap device
  • Automatically allows diluent into the breathing
    loop from the diluent side via a diaphragm if
    loop pressure drops below ambient
  • Flow Stop Control Switch on the LP hose from the
    diluent first stage feeding the ADV can be used
    to switch ADV off if free flowing or faulty

41
Mechanics and basic functioning of the
Inspiration and Evolution
  • BOUYANCY WING and AUTO AIR
  • All Inspiration and Evolution CCR come fitted
    with a wing and Auto-air as standard
  • The bouyancy wing and Auto-air are fed by LP feed
    from the diluent first stage
  • The Auto-air is an OC 2nd stage regulator
    connected directly to the diluent gas supply via
    the first stage regulator
  • The wing can be fitted with an optional
    crack-bottle for alternate gas source inflation

42
TDI Inspiration/Evolution Family of Rebreathers
Divers Course
  • Section 4
  • Classic Electronics Control

43
Classic Electronics Control
  • DUAL HANDSET CONTROLLERS
  • Liquid Crystal display on each with protective
    clear faceplate
  • 3 white magnetic Hall-Effect control Switches
    spring loaded
  • One black rotary power switch
  • Power switch up on
  • Power switch down Off

44
Classic Electronics Control
  • CLASSIC HANDSETS
  • Separate Power On/Off switch beware it can get
    caught in your gear and get switched off
  • Each handset shows if it is Master or Slave
  • Each handset displays the three cell readings in
    PPO2

45
Classic Electronics Control
  • Each handset displays the current setpoint
    setting at the top of the screen
  • Alarms are shown in text on the screen
  • There is a start-up menu that scrolls through
    basic pre-dive conditions to check diluent, and
    asks if you would like to calibrate and check the
    oxygen valve
  • The dive menu in water allows setpoint changes
    and changes to backlighting intensity
  • Your Instructor will guide you through the cycle

46
TDI Inspiration/Evolution Family of Rebreathers
Divers Course
  • Section 5 Vision Electronics Control

47
Vision Electronics Control
  • VISION
  • General
  • Owners personal data is shown on screen
  • Software Revision Version shown on screen
  • Optional software versions are available for
    Nitrox and Trimix diving
  • Vision Electronics available in German, Dutch,
    Italian, Spanish, Portugese, French and English
  • Functionality and displays similar in many
    respects to the classic Inspiration Handsets

48
Vision Electronics Control
  • SINGLE HANDSET SYSTEM
  • Liquid Crystal display mounted in aluminum case
  • 3 black buttons for commands
  • Twin redundant controllers C1 and C2 housed in
    Scrubber Lid
  • Power on by left switch
  • Power off by menu command by depressing right 2
    buttons simultaneously
  • Can select to power off C1 or C2(anytime) or All
    Off but not underwater

49
Vision Electronics Control
  • SINGLE HUD DEVICE
  • Dual redundant displays of twin LEDs one green
    one red connected to C1 and C2
  • Fiber optic cable running along mouthpiece hose
    connects to controllers in Scrubber Lid
  • Green LEDs are Good
  • Red LEDs are Rong or Alarms
  • HUD lighting intensity is user selectable
  • Read handset to get the detail of type of alarm
  • Visual alarms generated with audible alarms

50
Vision Electronics Control
  • OPTIONAL SCRUBBER TEMP STICK
  • Connects to Scrubber Lid via connectorised cable
    and status is displayed on the handset
  • It is NOT a CO2 monitor
  • Temp Stick is a temperature sensing system to
    detect where the main Burn Face of CO2
    absorption is taking place through the scrubber
    segments
  • It aids in scrubber maintenance monitoring

51
Vision Electronics Control
  • LCD HANDSET DISPLAY
  • Switches automatically from Surface Mode to Dive
    Mode at 1.2MSW ( 4FSW) and back again at 0.9MSW
    (3FSW)
  • The 3 PPO2 readings for the 3 cells are displayed
    across the middle of the LCD

52
Vision Electronics Control
  • Power on
  • Will auto-check controllers, batteries, cells,
    alarms and HUD. The temp stick, if fitted and
    connected, will also be checked
  • Your instructor will guide you through the menus,
    but read the User Instruction Manuals first
  • Status of Vision system components are displayed
    on the LCD as shaded or clear elements

53
Vision Electronics Control
  • SUB MENU SELECTION
  • Either CCR or DECO
  • Deco theory and handset options and control is
    covered fully in MOD 2 Course and is only touched
    on in this program
  • This Course addresses the Non-Decompression
    diving fundamentals of the CCR
  • Includes High and Low setpoint selection and
    changes and optional handset adjustments.

54
Vision Electronics Control
  • Calibration
  • Start-up asks if you want to calibrate
  • Can go direct to DIVE MODE for Dry Dive
  • Usually calibrate before each dive
  • Calibration procedure for cell mV output
    calibration
  • Prompts on screen to check O2 valve, diluent
    valve, and system bailout

55
Vision Electronics Control
  • AUTO SETPOINT SWITCHING
  • User selectable manual or automatically upon
    reaching a pre-determined depth
  • Latest S/W version allows different depths for
    auto-switching on descent and ascent

56
Vision Electronics Control
  • BUTTON CONTROLS
  • Center button is to select option on screen
  • Outside two buttons to scroll up and down the
    menu screens
  • Left button powers on the Controllers
  • Right two to enter power down sequence

57
TDI Inspiration/Evolution Family of Rebreathers
Divers Course
  • Section 6 Physiology
  • A Reflection for the CCR Diver

58
Physiology A Reflection for the CCR Diver
  • BASIC PREMISE
  • We need to breathe clean (CO2 and toxic gas
    free), appropriately oxygenated gas at all depths
    at all times to sustain life and to minimise DCS
    risk
  • Appropriate nitrox mixes are delivered to the
    diver under software control according to the
    PPO2 selected by the diver

59
Physiology A Reflection for the CCR Diver
  • ADDITIONAL CONCEPTS
  • The low and high PPO2 default setpoints of the
    Inspiration and Evolution are set at 0.7 and 1.3
    respectively
  • Ascent must be controlled at less than 9m per
    minute as per normal diving practice. DSC and DCI
    risks still apply
  • Dangers of hypoxia, hyperoxia, asphyxia and the
    insidious CCR carbon dioxide poisoning
    (hypercapnia) need examination
  • Lets review sources of contamination of breathing
    loop
  • NOAA toxicity guidelines apply for Whole Body and
    Pulmonary Toxicity

60
Physiology A Reflection for the CCR Diver
  • CO2 and HYPERCAPNIA
  • Humans consume O2 at a cellular level and
    generate CO2 as a waste product
  • Blood transports O2 to the cells and removes CO2
  • Blood exchanges CO2 for O2 at the lung Alveoli
  • The urge to breathe is driven by the level of CO2
    retained in the body (blood and cells)
  • With hypercapnia and elevated CO2 levels, the
    breathing rate is increased (panting dypsnea)
    to try to vent the lungs and alveoli

61
Physiology A Reflection for the CCR Diver
  • HYPERCANPNIA SYMPTOMS
  • Mild Symptoms
  • Headache
  • Anxiety and dizziness
  • Shortness of breath
  • Severe Symptoms
  • Strong anxiety bordering on panic
  • Muscular difficulty and loss of dexterity in
    closing mouthpiece to bail out to OC
  • Diluent flush doesnt seem to have any effect at
    first so divers often stop flushing when in fact
    they should continue flushing non-stop

62
Physiology A Reflection for the CCR Diver
  • RE-INHALATION OF CO2
  • CO2 normally removed by Sofnolime scrubber
  • Conditions when this doesnt occur properly
  • Scrubber expired or ignoring 3 hour duration rule
  • Strenuous activity on rebreather
  • Incorrect assembly of rebreather missing O-ring
  • Wet or flooded scrubber
  • Damaged mushroom valves gas goes backwards
  • Skip breathing or breath holding creates
    pockets of very high CO2 content in the
    breathing loop
  • Incorrect scrubber packing

63
Physiology A Reflection for the CCR Diver
  • DEPTH VERSUS CO2
  • As depth increases, work of breathing increases
    to push more gas molecules around the breathing
    loop. More CO2 is generated as a result.
  • As gas density of molecules increases the
    efficacy of the scrubber granules to absorb CO2
    across its surface decreases

64
Physiology A Reflection for the CCR Diver
  • HYPEROXIA
  • Too much oxygen results in O2 toxicity risk
  • Inspiration/Evolution alarm is set at a PPO2 of
    1.6 or above
  • Track O2 toxicity per NOAA tables (see manual)
  • At a default setpoint of 1.3, NOAA limit 180
    minutes - But 80 of that is 144 minutes
  • Do not exceed 80 of CNS and OTU tables
  • Need to monitor CNS and OTUs carefully on
    multi-dive days or multiple repeat dive days

65
Physiology A Reflection for the CCR Diver
  • SYMPTOMS OF HYPEROXIA
  • CONVENTID
  • CON Convulsions
  • V Visual disturbances/Tunnel vision
  • E Ears ringing (Tinnitus)
  • N Nausea
  • T Tingling or twitching (facial)
  • I Irritability
  • D Dizziness or vertigo

66
Physiology A Reflection for the CCR Diver
  • PULMONARY TOXICITY
  • O2 causes the alveoli surfaces in the lung to dry
    out thus slowly reducing lung efficiency
  • OTUs 1 minute of 100 oxygen breathing at the
    surface
  • Happens above a PPO2 of 0.5 thus very real danger
    for CCR and Inspiration/Evolution diving

67
Physiology A Reflection for the CCR Diver
  • HYPOXIA
  • Occurs if the PPO2 drops below 0.16 at any time
  • Real danger on ascent if solenoid fails
  • Real danger if Oxygen tank is off or empty
  • Symptoms can typically be breathlessness and
    panting, and lack of co-ordination
  • Unconsciousness resulting in drowning can be
    sudden and without warning

68
Physiology A Reflection for the CCR Diver
  • CNS TOXICITY AND OTUs
  • Real danger of convulsing and drowning if your
    CNS is not monitored properly
  • Always know the PPO2 in the loop and do a
    diluent flush to check any odd readings
  • Track your CNS and OTUs on the NOAA tables in
    your manuals

69
Physiology A Reflection for the CCR Diver
  • ASPHYXIA
  • Like strangulation it is caused by a shortage of
    oxygen and buildup of CO2
  • Restrictions in the breathing loop like a kinked
    mouthpiece hose can cause it
  • Easily noticed early in a dive
  • Ineffective or exhausted scrubber also can cause
    asphyxia
  • Eventually results in unconsciousness

70
TDI Inspiration/Evolution Family of Rebreathers
Divers Course
  • Section 7
  • Lets Go Dive the Rebreather - Preparation

71
Lets Go Diving the Rebreather - Preparation
  • EQUIPMENT ASSEMBLY and INSPECTION
  • Preparation
  • Assemble the rebreather according to a checklist
    (refer to manual), initially under Instructor
    guidance
  • Be meticulous and do not get distracted

72
Pay particular attention to the following during
assembly and inspection
Lets Go Diving the Rebreather - Preparation
  • Positive negative pressure tests
  • Cylinder contents analysis
  • Cylinder pressure on SPGs
  • HUD LEDs functioning (if HUD used)
  • Alarm working audibly
  • Listen for solenoid firing and alarm sounding
    when handsets switched on
  • Switches on handsets working normally
  • Mushroom valve checks on the mouthpiece assembly
  • Wing and Auto-Air checks
  • Scrubber packing, O-ring and
  • spacer functioning
  • Hose O-ring lubrication
  • Battery power levels

73
Lets Go Diving the Rebreather - Preparation
  • WEIGHTING AND TRIM
  • Ensure the unit is well weighted at the top.
  • Add to the sides on the waistband to trim
  • More weight needed if diving in a drysuit

74
Lets Go Diving the Rebreather - Preparation
  • MACHINE CALIBRATION
  • Absolutely critical part of the preparation
    process
  • Always put in of oxygen in the lid at 98 - all
    the air cannot be displaced from the lid
  • Ensure the millibar pressure is correctly entered
  • Is the Mbar reading on the Vision handset
    correct? (Automatically sensed)
  • Mbar readings are critical for altitude diving
  • Watch the cell readings rise during calibration
    and check for any slow or limited cells

75
Lets Go Diving the Rebreather - Preparation
  • Calibration of O2 cells O/P
  • Your instructor will demonstrate
  • Watch for rate of change of cell readings as
    oxygen is injected to Scrubber Lid
  • Only calibrate with the unit upright, vertical
    and dry inside

76
Lets Go Diving the Rebreather - Preparation
  • Calibration
  • Start-up asks if you want to calibrate
  • Can go direct to DIVE MODE
  • Usually calibrate before each dive
  • Calibration procedure for cell mV output
    calibration
  • Prompts on screen to check O2 value, diluent
    value bailout

77
Lets Go Diving the Rebreather - Preparation
  • BATTERY POWER MANAGEMENT
  • 2 x Lithium CRP2 batteries
  • One per handset/controller
  • Either change both batteries together, or cycle
  • New battery goes to slave, slave goes to master
    and old master is discarded
  • Backlighting consumes power
  • Solenoid firing consumes power
  • Alarms consume power

78
Lets Go Diving the Rebreather - Preparation
  • GETTING THE FEEL OF THE MACHINE ON LAND
  • Putting on the machine for a dry dive
  • Adjust straps to fit body correctly and tuck away
    loose ends
  • Power up and sequence handset control through to
    dive mode under guidance of Instructor
  • Go to a low setpoint of 0.5
  • Put on mask to prevent breathing through nose
  • Breathe on the machine while watching PPO2
    readings on handsets listen for solenoid firing

79
Lets Go Diving the Rebreather - Preparation
  • Dry dive simulations (approx 30 minutes)
  • These provide useful simulations in a safe
    environment for learning and troubleshooting

80
Lets Go Diving the Rebreather - Preparation
  • OVERFILLED BREATHING LOOP
  • Allow loop volume to increase by injecting a
    little diluent.
  • Get the feel of over pressurized loop
    inhibiting the exhale cycle
  • Release excess gas repeat again

81
Lets Go Diving the Rebreather - Preparation
  • UNDERFILLED BREATHING LOOP
  • Exhale fully through the nose, twice
  • Feel the effect of too little pressure in the
    loop, difficulty inhaling properly
  • Add gas using diluent button or, if there is an
    ADV, turn it on for volume adjustment

82
Lets Go Diving the Rebreather - Preparation
  • NORMAL LOOP VOLUME
  • Continue normal breathing mode while seated or
    stationary
  • Observe PPO2 readings and how closely they follow
    the setpoint
  • Listen to solenoid firing and ensure you are
    feeling fine on machine

83
Lets Go Diving the Rebreather - Preparation
  • GENTLE EXERCISE
  • Walk about with the rebreather on
  • Simulate moderate exercise
  • Notice breathing, rate increases, and solenoid
    firing more often than when at rest.

84
Lets Go Diving the Rebreather - Preparation
  • INCREASED WORK LEVEL
  • Jog in place for a couple of minutes, or do a few
    squats with the machine on to raise heart and
    respiratory rates
  • Observe PPO2 tracking, hear solenoid firing and
    notice little or no change in loop volume
  • The student should still feel fine and have no
    CO2 problems

85
Lets Go Diving the Rebreather - Preparation
  • LOW ALARM CHECK
  • Sit, relax and come off the machine breathe
    normal air
  • Blow air into the loop to drop the PPO2 below 0.4
  • Check for alarms and observe PPO2 coming back to
    setpoint again under automatic computer control

86
Lets Go Diving the Rebreather - Preparation
  • REDUNDANT CONTROLLER CHECK
  • Strictly under Instructor supervision
  • Repeat Low Alarm Check with handset or controller
    C1 switched off
  • Ensure redundant controller works, initiates
    alarms and brings PPO2 back to setpoint
  • Switch handset or controller C1 back on again

87
Lets Go Diving the Rebreather - Preparation
  • SETPOINT CHANGES
  • Switch to High and then back to the Low Setpoint
    when the PPO2 rises to 0.9 and observe PPO2 on
    handset
  • Test how long it takes to breathe the loop back
    down to a PPO2 of 0.5 at rest

88
Lets Go Diving the Rebreather - Preparation
  • OPEN CIRCUIT BAIL-OUT
  • Close mouthpiece and come off the loop
  • Switch to OC bailout Auto-Air, take 3 breaths,
    return to the loop and open mouthpiece
  • Observe loop volume increase as O2 is injected to
    bring PPO2 back up to setpoint because of the air
    you introduce to the loop
  • Alarm for Low PPO2 may also sound when returning
    to loop and filling it with air

89
Lets Go Diving the Rebreather - Preparation
  • DILUENT FLUSH
  • Inject diluent using manual addition button on
    inhalation counterlung while breathing in
  • Vent gas through over-pressure release valve
    while exhaling
  • Repeat three times and observe reduction in PPO2.
    Listen to solenoid firing. It is possible that
    the PPO2 may drop below 0.4 and cause an alarm

90
Lets Go Diving the Rebreather - Preparation
  • MANUAL GAS ADDITION
  • Give a small squirt of O2 with the manual
    addition button and observe the PPO2 reading
  • Repeat the exercise with diluent
  • Repeat to get a feel for the addition buttons

91
TDI Inspiration/Evolution Family of Rebreathers
Divers Course
  • Section 8
  • Lets Go Dive the Rebreather
  • In the Water

92
Lets Go Diving the Rebreather In the Water
  • Rule No 1
  • If in doubt bail out!
  • Rule no 2
  • If something feels wrong it is!

93
Lets Go Diving the Rebreather In the Water
  • DIVE PLANNING
  • Select depth and time for a safe no-deco time
  • Scrubber monitoring and planning (2.5 3 hour
    rule)
  • Gas volume planning enough for a bail-out
  • Oxygen planning CNS and OTUs
  • Is this a repetitive dive?
  • Thermal protection appropriate for conditions and
    duration of dive
  • Brief team, do ABCs and enter the water under
  • guidance of your Instructor

94
Lets Go Diving the Rebreather In the Water
  • FIRST IMPRESSIONS IN THE WATER
  • Silence
  • Bubble-free
  • Listen for the solenoid firing
  • Check PPO2 on the handsets every minute
  • Dynamic bouyancy change caused by
    computer-controlled oxygen
  • Unit is bouyant at shoulder level due to air
    volume in counterlungs and hoses
  • Add weight at the top for trim
  • Remember no matter how experienced you are on
    OC, you are now a beginner again

95
Lets Go Diving the Rebreather In the Water
  • EARLY TECHNIQUE POINTERS
  • Do not expect to get it right first time
  • Try to keep the loop volume at a minimum for
    comfort
  • Keep a steady depth level
  • Try to maintain a horizontal, neutral bouyancy,
    attitude while swimming
  • Use vertical attitude only when testing skills
    under instructor guidance
  • Be generous with weighting (1 or 2kg over)

96
Lets Go Diving the Rebreather In the Water
  • BASIC WATER SKILLS DEVELOPMENT
  • Mouthpiece opening and closing techniques
  • Open Circuit bail-out to Auto-Air
  • Diluent flushes and checking PPO2 drop
  • Check diluent flush predictions
  • Bouyancy normalisation while swimming
  • Constant checking of PPO2 on handsets
  • Understanding and reacting to alarm conditions
    (mostly simulated while on course)
  • Loop volume control

97
Lets Go Diving the Rebreather In the Water
  • BAD DAS DRILLS
  • In the event of in-water problems, rely on
  • BAD-DAS drills
  • B Bail-out to open circuit
  • A Anxiety breaths (3)
  • D Decide what to do
  • If returning to the loop, then
  • D Diluent flush breathe fresh gas
  • A Always know your PPO2 check handsets
  • S Skills. Apply appropriate skills gained during
    training to overcome the problem

98
Lets Go Diving the Rebreather In the Water
  • LOW O2 DRILLS
  • Manual flight
  • 1 Using O2 inflator
  • 2 Adding oxygen using O2 tank valve
  • 3 Using machine in semi-closed circuit mode
  • Low oxygen danger
  • 1 Solenoid stuck closed
  • 2 O2 tank empty or switched off
  • Handset failure or switched off
  • If both are blank, go open circuit or if gas
    volumes dictate, switch to semi-closed
  • circuit mode

99
Lets Go Diving the Rebreather In the Water
  • HIGH OXYGEN DRILLS
  • Open circuit bailout
  • Use of diluent flush to drop PPO2
  • Closing oxygen tank if solenoid fails open

100
Lets Go Diving the Rebreather In the Water
  • MENU MODE DRILLS
  • Sequencing through menu commands in water to
    become familiar with functionality
  • Changing Setpoints
  • Changing from one controller to the other
  • NEVER CALIBRATE UNDER WATER

101
Lets Go Diving the Rebreather In the Water
  • HYPERCAPNIA DRILLS
  • Open Circuit Bailout
  • Diluent flushes
  • Practice/Practice/Practice

102
Lets Go Diving the Rebreather In the Water
  • ELECTRONICS MALFUNCTIONS
  • Handset and controller problems
  • Cell errors or missing cells
  • Intermittent alarms
  • Poor PPO2 tracking to setpoint
  • Possible Loop Floods

103
TDI Inspiration/Evolution Family of Rebreathers
Divers Course
  • Section 9
  • Avoiding Rebreather Incidents
  • Safe Diving

104
Avoiding Rebreather incidents Safe Diving
  • All the training in the world is useless if you
    do not adopt the following as your personal
    mantra for CCR Diving
  • Safe Attitude
  • Safe and enhanced Awareness
  • Safe and structured Discipline

105
Avoiding Rebreather incidents Safe Diving
  • OPERATIONAL MAINTENANCE
  • Check battery connections are clean and dry
  • Ensure handsets are cleaned in fresh water,
    particularly Classic handsets with spring-loaded
    Hall-Effect slide switches
  • Keep O-rings well cleaned and lubricated to
    prevent abrasion and other damage

106
Avoiding Rebreather incidents Safe Diving
REMEMBER DURING PRE-DIVE PREPARATION
  • Properly assemble and check according to a check
    list
  • Do not get distracted during calibration
  • Do all the pre-dive checks and then go live for
    a short dry-dive to pre-breathe prior to
    entering water in order to ensure dynamic
    functionality of the machine

107
Avoiding Rebreather incidents Safe Diving
  • DIVE PLANNING
  • Break dive into logical waypoints to do checks
    and flushes for safety
  • Usual waypoints
  • _ 6msw (20fsw) bubble leak check
  • On descent - switch to high setpoints
  • On reaching bottom - diluent flush and check
    guages and handsets
  • After pre-set time or leaving bottom - diluent
    flush
  • On ascent (10msw or less) - gas venting to
    control bouyancy

108
Avoiding Rebreather incidents Safe Diving
  • REMEMBER ON THE DESCENT
  • Do a shallow (6msw/20fsw) bubble check
  • Descend slowly to control breathing loop volume
  • Watch the PPO2
  • Switch to high setpoint according to plan

109
Avoiding Rebreather incidents Safe Diving
  • REMEMBER ON THE ASCENT
  • PPO2 will drop, solenoid should fire, and oxygen
    should come into the loop quickly rapid
    bouyancy increase
  • Check PPO2 closely on ascent to reduce Hypoxic
    risk if there is insufficient O2 in the loop
  • Carefully control ascent rate
  • 3 potential bouyancy devices drysuit, wing and
    loop counterlungs

110
Avoiding Rebreather incidents Safe Diving
  • REMEMBER AT THE SURFACE
  • NEVER switch off the handsets or tanks at the
    surface above deep water
  • Only shut down after equipment has been taken off
  • You still need to watch your PPO2 if you breathe
    on the loop at the surface
  • Its the best snorkel you ever bought!!!

111
Avoiding Rebreather incidents Safe Diving
  • REMEMBER AFTER THE DIVE
  • Gas up again for the following dive
  • Check and replace batteries/scrubber
  • as necessary
  • Disinfect and clean as necessary
  • Conduct all other system checks to ensure correct
    functionality of cells and handsets
  • Log your dives

112
Avoiding Rebreather incidents Safe Diving
  • TDI Training and Manufacturers Manuals
  • Errors and troubleshooting are well documented
    for reference
  • Maintain your own service log for
    batteries/scrubber and other service needs
  • There is an elapsed On Time log kept on the
    controller until reset under menu control
  • Document your rebreather experiences
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