Suunto HELO2 manual Suunto Technical Rgbm decompression model, After dive planning

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10.2.1. Suunto Technical RGBM decompression model

Suunto's decompression model development originates from the 1980s when Suunto im- plemented Bühlmann's model based on M-values in Suunto SME. Since then research and development has been ongoing with the help of external and internal experts. In the late 1990s Suunto implemented Dr. Bruce Wienke's RGBM bubble model to work with the M model. The first commercial products with the feature were Vyper and Stinger. With these products the improvement of diver safety was significant.

Now Suunto has taken another leap in decompression modeling by introducing Suunto Technical RGBM decompression model with He tissues.

Suunto Technical RGBM model is a modified version of the M-value model. Calculation of the M-value model can be found in common dive literature. Modifications have been made to have the model follow RGBM theory as closely as possible. The modifications have been conducted with the help of Dr. Bruce Wienke. Functionality of Suunto Technical RGBM has been validated and verified to the depth of 120 m/393 ft with hundreds of test dives both in the field and in laboratory. The algorithm should not be used in deeper depths than the verified depth.

Suunto technical algorithm models the human body by using nine tissue groups. In theory the model is accurate if there are more tissue groups, but using more than nine tissue groups has no practical significance.

Tissue calculation aims to model the amount of nitrogen (N2) and helium (He) saturated in tissues. Ongasing and offgasing of saturated gas is modelled using the ideal gas equation. In practice this means that the total pressure of the nitrogen and helium tissues can be higher than the total pressure of the breathing gas, even without any exposure to pressure. For example, when a diver dives an air dive soon after a demanding trimix dive, the residual pressure of helium combined with a high nitrogen content cause the diver a decompression obligation very fast.

10.2.2. Diver safety and Suunto Technical RGBM model

Because any decompression model is purely theoretical and does not monitor the actual body of a diver, no decompression model can guarantee the absence of DCI. Suunto Technical RGBM model has many features that reduce the risk of DCI. The Suunto Technical RGBM algorithm adapts its predictions of both the effects of microbubble build- up and adverse dive profiles in the current dive series. The pattern and speed of decom- pression is adjusted according to the microbubble influence. The adjustment is also applied to the maximum combined nitrogen and helium overpressure in each theoretical tissue group. To add diver safety, offgasing is also slowed down compared to ongasing and the amount of slowing down depends on the tissue group.

Experimentally it has been shown that the body adapts to decompression to some degree when diving is constant and frequent. Two personal adjustment settings (P-1 and P-2) are available for divers who dive constantly and are ready to accept greater personal risk.

CAUTION

Always use the same personal and altitude adjustment settings for

 

the actual dive than for the planning. Increasing the personal adjust-

 

ment setting from the planned setting as well as increasing the altitude

 

adjustment setting can lead to longer decompression times deeper

 

and thus to larger required gas volume. You can run out of breathing

 

gas underwater if the personal adjustment setting has been changed

 

after dive planning.

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Contents HelO2 Page Welcome to the World of Suunto Diving Instruments Care and Maintenance of MY Suunto Diving Computer Welcome to the World of Suunto Diving Instruments Using HelO2 with Dive Manager and Dive PlannerOr death Or professional diving activitiesPhysician regarding your fitness before diving Stop, and Rgbm adjustments are correct ASC Time symbol and the upward pointing arrowUSE BACK-UP INSTRUMENTS! Make sure that you use back-up Diving with the dive computerBefore the instrument has counted down the no-fly time Batteries. Recycle or dispose of used batteries properlySymbol Button Press Main functions Button symbols and functionsSuunto HELO2 AT a Glance Navigating in the menusDown Long Enter Setting mode Setting the time Time mode settingsSetting the date Setting the unitsSetting the tones Setting the backlightAC water contacts Planning your dives Before DivingSuunto Technical Rgbm Dive computer limitations Emergency ascentsMixed gas diving Alarm indication Alarm reason Audible and visual alarmsError conditions Alarm indicationOut of calculation limits Gas mixInstalling the wireless transmitter Wireless transmissionPairing and code selection Omitted decompressionDisplay Indication Transmitting dataSetting the gases Mixed GAS Dive mode settingsDive Setting the dive-time alarm Setting the depth alarmSetting the personal/altitude adjustments Before you have ascended above this depthSetting the tank pressure alarm Setting the sample rateSetting the tank pressure Setting the HP codeDive mode activation Accessing Dive modeActivation and pre-checks Alt. adjustment value Altitude range Battery power indicationDiving at altitude Personal adjust- Condition Desired tables Ment value Personal adjustmentsHow the Altitude value is set Before divingRecommended Safety Stops Safety StopsMandatory Safety Stops Other personal injury, and deathDeep stops Diving-related information DivingBasic dive data Bookmark Ascent rate indicatorDecompression dives Than at the ceiling Ceiling, ceiling zone, floor and decompression rangeDisplay below the floor Accident, you should stay somewhat below the ceilingDisplay above the floor Display at the ceiling zoneBefore diving in Mixed GAS mode Diving in Mixed GAS modeDefault gas mix settings Oxygen and helium displaysGas change and multiple breathing gas mixes Oxygen limit fraction OLFDiving in Gauge mode After Diving Alarms Symbol on displaySurface interval Dive numberingDive Planning mode PLANnodec Plan modeRepetitive dive planning Flying after divingMemory mode PLANNoDec modeMixed GAS mode, it does not affect the calculations Dive numbering shown during dive planningDive logbook MEMLogbook Suunto Dive Planner SDP Dive historySuunto Dive Manager SDM Dive Planner. It ensures that you have a valid decompressionPage Water Contacts and Push Buttons Care and Maintenance of MY Suunto Diving ComputerBattery replacement and strap kits must be used FAQsWarranty Battery kit Battery ReplacementReplacing the battery Required toolsWireless transmitter battery replacement Battery compartment lid, indicating a leakMade in a proper manner to avoid any leakage of water into TransmitterStalling the transmitter battery Transmitter battery kitPage Technical Data Rgbm BatterySuunto Technical Rgbm decompression model Diver safety and Suunto Technical Rgbm modelAfter dive planning Oxygen exposure Altitude divingCopyright Trademark Intellectual PropertyPatent notice User’s responsibility Disclaimers12.2. CE Exclusions and Limitations Warranty PeriodOther important notices Access to Suunto warranty serviceLimitation of Liability Page Disposal of the Device EAD EAN GlossaryNo DEC Time Copyright Customer Service ContactsPage TWO Year Warranty Page Page Suunto Oy 4/2009
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