Tusa ZEN AIR IQ-950 User manual

3
CONTENTS
WARRANTY, NOTICES, DECOMPRESSION MODEL ....................................................................................................7
INITIAL ACTIVATION ........................................................................................................................................................8
FEATURES AND DISPLAYS ............................................................................................................................................9
INTRODUCTION AND CONTROL BUTTONS ..........................................................................................................10
OPERATING MODE STRUCTURE ...........................................................................................................................11
OPERATION AS A DIVE COMPUTER ......................................................................................................................12
AUDIBLE ALARM .....................................................................................................................................................12
BACKLIGHT ..............................................................................................................................................................14
POWER SUPPLY.......................................................................................................................................................15
WATCH FEATURES AND DISPLAYS ............................................................................................................................17
LOCAL DEFAULT TIME ............................................................................................................................................18
MAIN TIME ................................................................................................................................................................19
Set Main Time .......................................................................................................................................................20
ALTERNATE TIME ....................................................................................................................................................24
Set Alternate Time ................................................................................................................................................25
COUNTDOWN TIMER ...............................................................................................................................................26
Set CDT ................................................................................................................................................................27
CHRONOGRAPH ......................................................................................................................................................28
DAILY ALARM ...........................................................................................................................................................29
Set Daily Alarm .....................................................................................................................................................30
DIVE COMPUTER FEATURES AND DISPLAYS ...........................................................................................................31
BAR GRAPHS ...........................................................................................................................................................32
ALPHA / NUMERIC DISPLAYS ...............................................................................................................................34

4
CONTENTS (continued)
DIVE COMPUTER SURFACE MODES ..........................................................................................................................37
SURFACE MODE ......................................................................................................................................................38
Normal Surface Main ............................................................................................................................................40
Normal Surface ALT ..............................................................................................................................................41
ZEN AIR Battery Status ........................................................................................................................................41
TRT Status ............................................................................................................................................................42
NORM/GAUG SET MODES ......................................................................................................................................42
Setting FO2 for Nitrox Dives .................................................................................................................................43
SET F GROUP (FO2) ................................................................................................................................................45
Set FO2 Gas 1 ......................................................................................................................................................45
Set FO2 Gas 2 (3) ................................................................................................................................................46
Set FO2 50% Default ............................................................................................................................................47
SET A GROUP (ALARMS) ........................................................................................................................................47
Set Audible Alarm .................................................................................................................................................47
Set Depth Alarm....................................................................................................................................................48
Set EDT Alarm ......................................................................................................................................................49
Set NiBG Alarm.....................................................................................................................................................49
Set DTR Alarm ......................................................................................................................................................50
Set Turn Alarm .....................................................................................................................................................50
Set End Alarm ......................................................................................................................................................51
Set PO2 Alarm .....................................................................................................................................................51
SET U GROUP (UTILITIES) ......................................................................................................................................52
Set Wet Activation .................................................................................................................................................52
Set Units of Measure ............................................................................................................................................53
Set NORM Deep Stop ..........................................................................................................................................53
Set NORM Safety Stop .........................................................................................................................................54
Set Conservative Factor .......................................................................................................................................54
Set Backlight Duration ..........................................................................................................................................55
Set Sampling Rate ................................................................................................................................................55
Set TRT 1 (2, 3) ....................................................................................................................................................56

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CONTENTS (continued)
SERIAL NUMBER .....................................................................................................................................................57
NORM PLAN MODE ..................................................................................................................................................57
FLY MODE .................................................................................................................................................................60
DESAT MODE (NORM) .............................................................................................................................................61
NORM/GAUG LOG MODE ........................................................................................................................................62
HISTORY MODE (NORM/GAUG) .............................................................................................................................65
NORM DIVE MODES ......................................................................................................................................................67
POSITIONING OF THE ZEN AIR ..............................................................................................................................69
Link Interruption Underwater ................................................................................................................................69
NO DECO DIVE TIME REMAINING (DTR) ...............................................................................................................70
Oxygen Accumulation Time Remaining (OTR) .....................................................................................................71
Air Time Remaining (ATR) ....................................................................................................................................71
ATR Alarm .............................................................................................................................................................72
ASCENT RATE INDICATOR (ASC) ..........................................................................................................................73
NORM NO DECO DIVE MODE .................................................................................................................................74
No Deco Deep Stop ..............................................................................................................................................76
No Deco Safety Stop ............................................................................................................................................78
CAUTIONARY MODES ...................................................................................................................................................79
DECOMPRESSION ...................................................................................................................................................80
VIOLATION MODES ..................................................................................................................................................82
HIGH PO2 ..................................................................................................................................................................88
HIGH O2 ...................................................................................................................................................................89
SWITCHING GAS MIXES AND TRTS ............................................................................................................................91
SWITCHING (NORM) ................................................................................................................................................92
NORM POST DIVE MODES ...........................................................................................................................................95
POST DIVE FIRST 10 MINUTES ON SURFACE ......................................................................................................96
POST DIVE AFTER 10 MINUTES ON SURFACE ....................................................................................................97

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CONTENTS (continued)
UPLOADING SETTINGS AND DOWNLOADING DATA ...........................................................................................98
GAUGE OPERATING MODE .........................................................................................................................................99
GAUG SURFACE DISPLAYS .................................................................................................................................100
GAUG DIVE DISPLAYS ..........................................................................................................................................101
FREE DIVE OPERATING MODE ..................................................................................................................................103
FREE SURFACE DISPLAYS ...................................................................................................................................104
FREE COUNTDOWN TIMER (CDT) .......................................................................................................................106
Set CDT ..............................................................................................................................................................107
FREE EDT ALARM..................................................................................................................................................108
Set EDT Alarm ....................................................................................................................................................108
FREE DEPTH ALARMS (DA)..................................................................................................................................109
Set DA (1, 2, 3) ...................................................................................................................................................109
FREE DIVE DISPLAYS ...........................................................................................................................................110
FREE DIVE ALARMS ..............................................................................................................................................111
REFERENCE ................................................................................................................................................................115
CARE AND CLEANING...........................................................................................................................................116
INSPECTIONS AND SERVICE ...............................................................................................................................116
ZEN AIR BATTERY REPLACEMENT .....................................................................................................................117
TRT BATTERY REPLACEMENT ............................................................................................................................121
INSTALLING A TRANSMITTER ON A REGULATOR.............................................................................................123
TRANSMITTER COMPATIBILITY WITH NITROX ..................................................................................................124
ALTITUDE SENSING AND ADJUSTMENT ............................................................................................................125
CHART OF OXYGEN EXPOSURE LIMITS ............................................................................................................126
CHARTS OF NO DECOMPRESSION LIMITS AT ALTITUDE ................................................................................127
SPECIFICATIONS ...................................................................................................................................................128
ERROR DURING A DIVE ........................................................................................................................................134
INSPECTION/ SERVICE RECORD .........................................................................................................................135
TUSA INTERNATIONAL CONTACTS .....................................................................................................................136

7
LIMITED TWO-YEAR WARRANTY
For details, refer to the Product Warranty Registration Card provided.
COPYRIGHT NOTICE
This manual is copyrighted, all rights are reserved. It may not, in whole or in part, be copied, photocopied, reproduced,
translated, or reduced to any electronic medium or machine readable form without prior consent in writing from Tabata
USA, Inc. and Tabata Corp. Ltd. / 2002 Design.
ZEN AIR Owner's Manual, Doc. No. 12-5231
© 2002 Design, 2010
San Leandro, CA USA 94577
TRADEMARK NOTICE
TUSA, the TUSA logo, ZEN AIR, and the ZEN AIR logo, are all registered and unregistered trademarks of Tabata USA
and Tabata Corp. Ltd. All rights are reserved.
PATENT NOTICE
U.S. Patents have been issued, or applied for, to protect the following design features:
Air Time Remaining (U.S. Patent no. 4,586,136 and 6,543,444), Data Sensing and Processing Device (U.S. Patent no.
4,882,678), Ascent Rate Indicator (U.S. Patent no. 5,156,055).
CE
The CE mark is used to mark conformity with the European Union EMC directive 89/336/EEC. TUSA dive instruments
fulfill the required EU directives.
EN 13319 "Diving accessories - Depth gauges and combined depth and time measuring devices - Functional and
safety requirements, test methods" is a European diving depth gauge standard. The ZEN AIR is designed to comply
with this standard.
DECOMPRESSION MODEL
The program within the ZEN AIR simulates the absorption of nitrogen into the body by using a mathematical model.
This model is merely a way to apply a limited set of data to a large range of experiences. The ZEN AIR dive computer
model is based upon the latest research and experiments in decompression theory. Still, using the ZEN AIR, just
as using the Navy (or other) No Decompression Tables, is no guarantee of avoiding decompression
sickness, i.e. “the bends.” Every diver’s physiology is different, and can even vary from day to day. No machine
can predict how your body will react to a particular dive profile.

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ZEN AIR Watch/Dive Computers are placed in a Deep Sleep mode prior to
being shipped from the factory. The intent is to extend storage life of the Battery
for up to 7 years, before the unit is initially placed in service.
In this mode, Date and Time are updated as they normally would be. However,
they are not displayed. Upon waking the ZEN AIR up, the correct Date and
Pacific Time will be displayed and it will be ready to operate with full functions.
To wake the ZEN AIR up from Deep Sleep mode, simultaneously depress the
upper/right (S) and lower/left (A) buttons for 2 to 3 seconds until the display
comes full ON displaying the MAIN TIME screen, then release them.
NOTE: Once the ZEN AIR is brought out of the Deep Sleep
mode, it can only be placed back in it by the factory.
NOTICE
STORAGE and INITIAL ACTIVATION

9
FEATURES AND DISPLAYS

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INTRODUCTION
Welcome to TUSA and thank you for choosing the ZEN AIR !
It is extremely important that you read this Owner's Manual in sequence and understand it
completely before attempting to use the ZEN AIR as a dive computer.
Remember that technology is no substitute for common sense, and a dive computer only
provides the person using it with data, not the knowledge to use it.
CONTROL BUTTONS
The ZEN AIR features four Control Buttons that allow you to select mode options and
access specific information. They are also used to link the Transmitter(s), enter Settings,
activate the Backlight, and acknowledge the Audible Alarm.
Throughout this manual they will be referred to as the M, S, L, and A buttons.
• Upper/Left - Mode (M) button
• Upper/Right - Select (S) button
• Lower/Right - Light (L) button
• Lower/Left - Advance (A) button
M
A
S
L

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OPERATING MODE STRUCTURE
Unless it is operating in Dive Computer mode, the ZEN AIR will
be ON in the default WATCH MAIN TIME (home time) mode
(Fig. 1), like a standard WATCH, until the Mode is changed.
The M button is used to access 4 other Modes that include Alter-
nate Time Mode, Countdown Timer, Chronograph (stop watch/
lap timer), and Daily Alarm. It is also used to revert to the Local
Default Time display and access Computer Modes.
The screens of the Main Modes and Sub Modes will remain
on display until a button is pressed to access another screen
or Mode, activate a sequence, or for 2 minutes if no button is
pressed. The Chronograph remains on display as long as it is
running unless another Mode is accessed.
When Wet Activation is set On, the ZEN AIR will enter selected
Dive Mode upon descent to 5 FT (feet)/1.5 M (meters) for 5
seconds, regardless of what operating mode it is in.
WARNING: When Wet Activation is set OFF, the
ZEN AIR must be in Dive Surface Mode (NORM,
GAUG, or FREE) prior to the first dive of a new
series. Commencing a dive while in Watch
modes will not activate Dive Mode unless Wet
Activation is set ON.
Main Sequence
(while at home)
Main Time
Alternate Time
Countdown Timer
Chronograph
Daily Alarm
Alternate Sequence
(at a travel location)
Alternate Time
Main Time (home)
Countdown Timer
Chronograph
Daily Alarm
Fig. 1 - MAIN TIME

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OPERATION AS A DIVE COMPUTER
The ZEN AIR features 3 Dive Computer (DC) Operating Modes,
NORM (Fig. 2A) which is used for Air and Nitrox dives, GAUG
(Fig. 2B) used for dives in which Nitrogen-Oxygen calculations
are not performed, and FREE (Fig. 2C) used for activities that do
not use SCUBA.
Entering Settings and Plan Mode are only available in NORM
SURF Mode which also allows access to Battery/Transmitter
Status, Fly, Desat, Log, and History Modes. Tank Pressure is
displayed if a Transmitter is active and Linked with the ZEN AIR.
GAUG Mode only allows access to Battery/Transmitter Status,
Fly, Log, and History Modes. It also displays Tank Pressure.
FREE Mode only allows access to ZEN AIR Battery Status, Log,
and History Modes. It does not display Tank Pressure.
AUDIBLE ALARM
Most warning situations that activate the Audible Alarm while
operating in NORM or GAUG Mode will sound 1 beep per
second for 10 seconds, or until the situation is corrected, or it is
acknowledged by pressing and releasing the S button (less than
2 seconds). After being acknowledged and the situation correct-
ed, the Alarm will sound again upon reentry into the warning
situation, or entry into another type of warning situation.
Fig. 2 - DC MODES
2A
2B
2C

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FREE Dive Mode has its own set of Alarms which emit 3 short beeps either 1 or 3 times
which cannot be acknowledged or set Off.
The Audible will not be active if the Alarm is Set OFF (a group A setting).
Situations that will activate the NORM/GAUG 10 second Alarm include -
• Air Time Remaining (ATR) at 5 minutes, then again at 0 minutes.
• Turn Pressure at the Set Point selected (Transmitter 1).
• End Pressure at the Set Point selected (active Transmitter).
• Descent deeper than the Max Depth Set Point selected.
• Dive Time Remaining at the Set Point selected.
• Elapsed Dive Time at the Set Point selected.
• High PO2 of 1.60 ATA or the Set Point selected.
• High O2 of 300 OTU (single or daily exposure).
• Nitrogen Bar Graph at the segment Set Point selected.
• NORM/GAUG Ascent Rate exceeds 60 FPM (18 MPM) when deeper than 60 FT (18
M), or 30 FPM (9 MPM) at 60 FT (18 M) and shallower.
• Loss of the active Transmitter Link signal for more than 15 seconds during a dive.
• Entry into Decompression Mode (Deco).
• Conditional Violation (above a required Deco Stop Depth for less than 5 minutes).
• Delayed Violation (above a required Deco Stop Depth for more than 5 minutes).
• Delayed Violation (a Deco Stop Depth greater than 60 FT/18 M is required).
• Delayed Violation (Maximum Operating Depth of 330 FT/100 M is exceeded).
• A Gas Switch to another tank would expose the diver to PO2 greater than 1.60 ATA.
• Watch Daily Alarm reaches time set (disabled during Dive Modes).
• Watch Mode Countdown Timer reaches 0:00.

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A single short beep (which cannot be disabled) is emitted for the following -
• Upon completion of a Hot Swap battery change.
• Change from Delayed to Full Violation 5 minutes after the dive.
3 short beeps (which cannot be disabled) are emitted for the following -
• NORM/GAUG Ascent Rate is 51 to 60 FPM (15.1 to 18 MPM) when deeper than
60 FT (18 M), or 26 to 30 FPM (7.5 to 9 MPM) at 60 FT (18 M) and shallower.
• FREE Dive Elapsed Dive Time Alarm (3 beeps every 30 seconds if set On).
• FREE Dive Depth Alarms 1/2/3 (set sequentially deeper) - each 3 beeps 3 times.
• FREE Dive NIBG Alarm (Caution zone, 4 segments) - 3 beeps 3 times.
• Entry into Deco during a FREE Dive (Permanent Violation) - 3 beeps 3 times.
• Free Dive Mode Countdown Timer reaches 0:00 - each 3 beeps 3 times.
During the following NORM Dive situations, the 10 second continuous tone will be fol-
lowed by a 5 second steady beep that will not turn off when acknowledged -
• Ascending above a required Decompression Ceiling Stop Depth for more than 5
minutes (referred to as a Delayed Violation).
• Decompression requires a Ceiling Stop Depth of 70 FT/21 M or deeper.
• Being on the Surface for 5 minutes after a Conditional Violation.
BACKLIGHT
To activate the Backlight - press the L (lower/right) button.
• The Backlight will activate and illuminate the display for button depression time* plus
the user set Duration time of 0, 5, or 10 seconds, for a maximum of 20 seconds.
(*The Backlight turns Off if the button is held depressed for more than 10 seconds.)
• Press the button again to activate as desired.

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NOTE: Extensive use of the Backlight reduces
estimated Battery life. Also, the Backlight does
not operate during a Low ZEN AIR Battery Con-
dition or when the ZEN AIR is connected to a PC.
POWER SUPPLY
The ZEN AIR uses (1) 3 volt CR2430 Lithium Battery. Used as a
Dive Computer, the battery should operate normally for 1 year
or 300 dive hours if 2 dives are conducted during each dive
period. Voltage is checked every 2 minutes on the surface.
• If voltage of the ZEN AIR decreases to the Warning level
(2.75 volts), the Battery icon will appear on Surface
display screens (Fig. 3a) as an indication that the Battery
should be changed prior to commencing a series of dives.
• If the ZEN AIR's voltage decreases to the Alarm level (2.50
volts), the Battery icon will flash and the message CHG >
BAt will scroll (Fig. 4a) for 5 seconds, then operation will
automatically revert to Main Time Mode. The ZEN AIR
would then only operate in Watch modes until the Battery
becomes completely depleted.
• Low Battery conditions are not displayed during dives.
• If a Low Battery Condition was not displayed prior to
starting a Dive, and a Low Battery Condition occurs during
the dive, there will be sufficient Battery power remaining to
maintain operation for the remainder of that dive. Fig. 4 - LOW BATTERY
ALARM
Fig. 3 - LOW BATTERY
WARNING
a
a

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Transmitters (TRTs) each use (1) 3 volt, CR2 Lithium Battery. A
TRT's battery should provide normal operation for 1 year or 300
dive hours. TRTs check battery voltage when they are pressur-
ized and will send a Low Battery signal to the Receiver in the
ZEN AIR when the voltage drops below the Warning level.
• TRT Low Battery conditions are only displayed on Status
screens that can be accessed from the Surface Display.
To check the condition of the ZEN AIR or a TRT's Battery if
NORM or GAUG Mode is selected, depress the S button for 2
seconds while viewing the Surface Main, then release it.
• As the button is depressed, the ZEN AIR's Receiver will
activate, if in NORM or GAUG Mode.
• 2 seconds later, the ZEN AIR's Battery status will be
displayed for 3 seconds (Fig. 5), then -
• if active and linked, TRT 1's Battery status will be displayed
for 3 seconds (Fig. 6A), then -
• if active and linked, TRT 2's Battery status will be displayed
for 3 seconds, then -
• if active and linked, TRT 3's Battery status will be displayed
for 3 seconds, then -
• the display will then revert to Surface Mode.
• If a TRT is not active and linked, the message NOT AvAil
(not available) will be displayed (Fig. 6B).
Fig. 5 - ZEN AIR BATT GOOD
Fig. 6B - TRT NOT REPORTING
Fig. 6A - TRT BATT LOW

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WATCH
FEATURES AND DISPLAYS

18
LOCAL DEFAULT TIME
Watch Main Time (Fig. 7) is the current Time at your home
location and is normally selected as the Local Default Time.
The normal Watch screen sequence accessed with momentary
presses (less than 2 seconds each) of the M button is -
Main Time > Alternate Time > Countdown Timer >
Chronograph > Daily Alarm
Watch Alternate Time (Fig. 8), which is set by Hour Differen-
tial, is the current Time displaying Am (or Pm) at a remote travel
location. Upon arrival at the location, Alternate Time can be
interchanged with Main Time to make it the Local Default Time
while visiting the travel location.
The M button will then access the screens in this sequence -
Alternate Time > Main Time > Countdown Timer >
Chronograph > Daily Alarm
While viewing Alternate Time, depressing and holding the S
button for 2 seconds will replace Main Time with Alternate Time
that will then become the Local Default Time until changed.
Fig. 7 - MAIN TIME
Fig. 8 - ALTERNATE TIME

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While viewing any of the Watch Mode displays, depressing the
M button for 2 seconds or if no button is pressed for 2 minutes,
operation will revert to the Watch Default Time screen selected.
MAIN TIME, information displayed includes (Fig. 9):
> Nitrogen Bar Graph, if any after NORM/FREE dives.
> O2 Bar Graph, if any after NORM Nitrox dives.
> Daily Alarm icon (clock) if it is set On (Fig. 9a).
> Day of the Week graphic MON (or TUE, WED, THU, FRI,
SAT, SUN).
> Month and Day (Day and Month if set for Metric)
> Time of Day (hr:min:sec) with AM (or PM) icon if 12 Hour
Format, no icon if 24 Hour.
> Battery icon, if a Low Battery Condition exists.
• M (repeatedly, < 2 sec each time) will step through Main
Watch Modes.
• M (2 sec) will access Dive Computer Surface Mode
(NORM, GAUG, or FREE).
• A (< 2 sec) will access NORM/GAUG Log and History
Modes.
• A (2 sec) will access the ALT screen (Elev, Temp, Date).
• S (< 2 sec) will silence and acknowledge the Daily Alarm.
• L (press) will activate the Backlight.
• A and S buttons (simultaneously 2 sec) will access the SET
TIME Menu. Fig. 9 - MAIN TIME
(12 Hour Format)
a

20
WATCH ALT DISPLAY, information includes (Fig. 10):
> Altitude graphic (EL2 to EL7), if above 3000 feet (915
meters), blank if below.
> Temperature with degrees icon and graphic F (or C).
> Date (Month.Day or Day.Month).
• After 5 seconds, operation will revert to the Watch Default
Time screen.
• A (< 2 sec) will revert to the Watch Default Time screen.
• L (press) will activate the Backlight.
SET MAIN TIME
This mode allows the Date and Time of Day to be set which will also serve as the basis for
Watch Alternate Time values.
> Set screens >>> Date Format >> Hour Format >> Time >> Date
> Day of the Week is set automatically when the Date is set.
> When the ZEN AIR is operating in Dive Computer mode, Date is displayed only to
identify dives when they are accessed in the LOG Mode
• A (repeatedly, < 2 sec each time) will step through the menu items.
• M (2 sec) at any time, or if no button is pressed during a period of 2 minutes,
operation will revert to the Watch Default Time screen.
Fig. 10 - WATCH ALT

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Set Date Format
While viewing the Watch Default Time screen, depressing the
A and S buttons simultaneously for 2 seconds will access the
Set Date Format screen displaying the graphic dAtE and the Set
Point M - D or D - M flashing (Fig. 11).
> M - D means Month will be displayed to the left of Day.
> D - M means Day will be displayed to the left of Month.
• S (< 2 sec) will toggle between M - D and D - M.
• A (< 2 sec) will save the Set Point and access the Set Hour
Format screen with the Set Point flashing.
Set Hour Format
The Set Hour Format screen displays the graphic HR with the
clock icon and the Set Point 12 or 24 flashing (Fig. 12).
• S (< 2 sec) will toggle between 12 and 24.
• A (< 2 sec) will save the Set Point and access the Set Time
screen.
Fig. 11 - SET DATE FORMAT
Fig. 12 - SET HOUR FORMAT