54
VT 4.0 OPERATING MANUAL
© 2002 Design, 2011
Doc. No. 12-5213-r02 (9/6/11)
ALTITUDE SENSING AND ADJUSTMENT
Prior to the first dive of a series of repetitive dives, Altitude (i.e., ambient pressure) is measured upon activation then every 15
minutes until a dive is made.
> Measurements are only taken when the unit is dry.
> Two readings are taken, the second reading 5 seconds after the first. The readings must be within 1 foot (30 cm) of each
other to record that ambient pressure as the current Altitude.
> No adjustments are made during any time that the Wet Contacts are bridged.
When diving in high altitude waters from 3,001 to 14,000 feet (916 to 4,270 meters), the VT 4.0 automatically adjusts to these
conditions providing corrected Depth, and reduced No Deco and O2 Times at intervals of 1,000 feet (305 meters).
At an elevation of 3,001 feet (916 meters), Depth calibration automatically changes from feet of seawater to feet of fresh water.
This is the first adjustment to the algorithm.
When the Conservative Factor feature is set On, NDLs are calculated based upon the next higher 3,000 foot (915 meter) Alti-
tude. All adjustments for Altitudes greater than 11,000 feet (3,355 meters) are then made to allowable dive times for 14,000
feet (4,270 meters). At Sea Level, calculations are based upon an Altitude of 6,000 feet.
The VT 4.0 will not function above 14,000 feet (4,270 meters).
RESET DURING A DIVE
The intent of the feature is to assist the diver by providing indication of Depth during the ascent and encourage return of the af-
fected unit to the factory for evaluation prior to further use.
If the VT 4.0 Resets (i.e.; is On, turns Off, then turns On again) for any reason during any dive, Nitrogen, O2, and ATR calcula-
tions are terminated (upon turning Off). Upon turning On, the graphic ERROR and the UP Arrow icons appear solid, and Current
Depth is displayed (Fig. 146). No other information is displayed. The Backlight remains operational.
Upon surfacing, the graphic ERROR is displayed solid for 5 seconds (Fig. 147), then the unit will shut off with operation blocked
permanently, even if the battery is replaced and attempts are made to reactivate the unit.
WARNING: In the unlikely event that this should ever happen, DO NOT continue diving with the
unit, return the it to the factory as soon as possible.
WARNINGS
Decompression diving, or diving deeper than 130 FT (39 M), will greatly increase your risk of decompression sickness.
Decompression diving is inherently hazardous and greatly increases your risk of decompression sickness, even when performed
according to the dive computer's calculations.
Using an VT 4.0 is no guarantee of avoiding decompression sickness.
The VT 4.0 enters Violation Mode when a situation exceeds its capacity to predict an ascent procedure. These dives represent
gross excursions into decompression that are beyond the boundaries and spirit of the VT 4.0's design. If you are following
these dive profiles, Oceanic advises that you should not use an VT 4.0.
If you exceed certain limits, the VT 4.0 will not be able to help you get safely back to the surface. These situations exceed
tested limits and can result in loss of some functions for 24 hours after the dive in which a violation occurred.
Fig. 146 - ERROR DURING
DIVE
Fig. 147 - ERROR UPON
SURFACING
Summary of Contents for VT 4.0
Page 4: ...4 VT 4 0 OPERATING MANUAL 2002 Design 2011 Doc No 12 5213 r02 9 6 11 FEATURES FUNCTIONS...
Page 10: ...10 VT 4 0 OPERATING MANUAL 2002 Design 2011 Doc No 12 5213 r02 9 6 11 NORM SURFACE MODES...
Page 19: ...19 VT 4 0 OPERATING MANUAL 2002 Design 2011 Doc No 12 5213 r02 9 6 11 DIVE MODE FEATURES...
Page 24: ...24 VT 4 0 OPERATING MANUAL 2002 Design 2011 Doc No 12 5213 r02 9 6 11 NORM DIVE MODES...
Page 31: ...31 VT 4 0 OPERATING MANUAL 2002 Design 2011 Doc No 12 5213 r02 9 6 11 GAS TMT SWITCHING...
Page 34: ...34 VT 4 0 OPERATING MANUAL 2002 Design 2011 Doc No 12 5213 r02 9 6 11 GAUG OP MODE...
Page 39: ...39 VT 4 0 OPERATING MANUAL 2002 Design 2011 Doc No 12 5213 r02 9 6 11 FREE DIVE OP MODE...
Page 44: ...44 VT 4 0 OPERATING MANUAL 2002 Design 2011 Doc No 12 5213 r02 9 6 11 COMPASS MODE...
Page 55: ...55 VT 4 0 OPERATING MANUAL 2002 Design 2011 Doc No 12 5213 r02 9 6 11 TECHNICAL DATA...
