Tusa IQ-800 User manual

1
Contents
IQ-800 Flow Chart 3
1. Introduction 4
2. Key Features 4
3. Common Sense Warnings 4
4. Accessing Display Modes 7
5. Time Mode 8
6. Dive Set Mode 10
7. Dive Plan Mode 12
8. Dive Log Mode 14
10. Dive Profile Mode 20
11. PC Transfer Mode 22
12. Time Set Mode 23
13. Dive Mode 24
14. Altitude Setting 35
15. Battery Level Icon 37
16. Battery Replacement 37
17. Units of Measurement 38
18. General Handling 38
19. Warranty 39
22. Technical Specifications 43

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DC-Sapience
Selected display features
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2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
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18
19
20
21
22
23
24
1
2
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4
5
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12 24
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Decompression stop violation
Decompression time
Decompression depth
Date, safety stop time
Residual nitrogen bar graph
Don’t fly icon
Current time
Total dive time, current depth
Sea/Fresh water icon
Mode button (A)
Nitrox icon
Mode, log number
Ascent rate indicator
Ascent rate warning
Low battery warning
Altitude setting
Set, backlight button (C)
FO2, NDL time, dive time
PO2 icon
Residual Oxygen bar graph
Current dive number
Select button (B)
Surface interval, Safety Factor
Total ascent time

3
IQ-800 Flow Chart
AKey
BKey：Select
CKey：Set
B+CKey：
LCDallON
BKey：Select
CKey：Set
B+CKey5〜6sec：
FT/mchange
BKey：Select
CKey：Set
AKey
BKey：N→…→2→1→N→…
BKeyHold：(FastScrolling)N→…→2→1
PROFILEMODE
B,C,EKey：invalid

CKey：Pause(Divecountstop)
TIMEMODE
TIMESETMODE
DIVESETMODE
PLANMODE
PCTRANSFERMODE
ActualSize
rev.7改
2004.2.27
BKey
release
BKey
hold
DIVEMODE
BKeyorCKey：
ELon5s
B+CKey：Alarmaudition
AKey

AKey
Deco NDL
Non‑Deco Demand
Ascentratewarning PO2limitedwarning OLIlevelwarning
SafetyStop
RangeOVER
AKeyorBKeyorCKey：ELON5s
ESwitch
BKey：invalid
CKey5〜6s：HistoryClear
HISTORYMODE
NonResidualNitrogen ResidualNitrogen
BKey
B BB B
Second→Minute→Hour→12h/24h→
B B B
→Year→Month→Day→
BKey
AKey
AKey
AKey AKey
TIMEMODE
‑Modekey‑ ‑Setkey‑
‑Selectkey‑
B B
SURF.T→DEPTHRANK→
FO2→USF→SOUND/VIBE→Sea/Fresh→
B B B B
BKeyrelease
BKeyhold
CKey
CKey：N‑1→N‑2→…→1‑1→1‑2
CKeyHold：(FastScrolling)N‑1→…→2‑1→1‑1
BKey：1‑2→1‑1→…→N‑2→N‑1
BKeyHold：(FastScrolling)1‑1→2‑1→…→N‑1
BKey
LOGMODE
……
CKeyBKey
ESwitch
CKeyHold:
Set(FastScrolling)

4
1. Introduction
Congratulations on your choice of the TUSA IQ-800 Dive Computer.
The IQ-800 is a compact and sophisticated dive instrument that will
give you reliable, trouble free performance, dive after dive.
The information in this manual has been developed for your safety.
Please read and understand this manual completely before using
your new TUSA dive computer.
2. Key Features
Among the IQ-800’s key features:
• Can handle both air and nitrox
• User changeable FO2 setting
• Visual, audible, and vibrating alarms
• Safety stop function
• Decompression and non-decompression dive information
• Maximum depth alarm
• Dive time alarm
• Display backlight
• User changeable battery
3. Common Sense Warnings
As is true of every piece of diving equipment, including all dive
computers, the IQ-800’s abilities are not limitless. There are certain
limitations and restrictions of which you must be aware, and certain
precautions you must take when using the IQ-800.

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The IQ-800 is designed for use by certified, recreational divers
who have maintained a sufficient level of knowledge and skill
proficiency through a combination of formal training, ongoing study
and experience. It is not intended for use by persons who lack
the qualifications, and thus may not be able to identify, assess,
and manage the risks scuba diving entails. Use of the IQ-800 in
conjunction with Enriched Air Nitrox (EANx) further requires that the
diver be trained and certified for Nitrox diving.
The IQ-800 is not intended for use by commercial, military or
technical divers whose activities may take them beyond the
commonly accepted depth limits for recreational diving.
The IQ-800 is designed for use by divers breathing either normal
compressed air or Enriched Air Nitrox (EANx) mixtures whose fraction
of Oxygen falls within a range of 22 to 99 percent.
Although the IQ-800 is capable of calculating decompression stop
requirements, this ability is provided as a safety feature only, should
a diver accidentally exceed the No-Decompression Limits (NDLs).
Dives requiring mandatory stage decompression carry substantially
greater risk than dives made well within no-decompression limits.
Decompression diving is widely believed to entail substantially
greater risk of decompression illness than dives made well within
the No-Decompression Limits (NDL). The IQ-800 provides
decompression stop information solely as a contingency in case
divers accidentally exceed the No-Decompression Limits. It is not
designed or intended for use as a tool to plan or execute dives
that participants know will entail mandatory decompression.
WARNINGS
Before using the IQ-800, it is extremely important you read the
following points as well as similar warning and caution notices
that appear throughout this manual. Failure to do so could result
in damage to or loss of equipment, serious personal injury, or
death.

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The IQ-800 is designed to be used by only one diver at a time. Divers
should not share a single IQ-800, or any dive computer, on the same
dive. Additionally, no diver should lend his or her IQ-800 to anyone else
until it calculates that no measurable residual nitrogen remains after
previous dives, and displays neither the “Desaturation Time” nor “No Fly”
indicators while in Surface Mode. Further, no diver should use his or her
IQ-800 for repetitive dives unless that same IQ-800 has accompanied
him or her on all previous dives in the same repetitive dive series.
Neither the IQ-800, nor any other dive computer presently available,
physically measures the amount of nitrogen present in body tissues, or
the rate at which this nitrogen is being absorbed or released. Instead,
the IQ-800 monitors depth and time, and uses this data to work a
mathematical formula designed to emulate how individuals in good
general health and whose physical characteristics do not place them
among those at higher risk of decompression illness are assumed
to absorb and release nitrogen from body tissues. Thus, the IQ-800
cannot compensate for factors such as age, obesity, dehydration, cold
or exertion, which experts believe place divers at greater risk of DCI. If
these, or similar factors apply to you, use the IQ-800, and any other dive
computer or dive table, with even greater caution.
Experts still know surprisingly little regarding the exact nature and causes
of decompression illness (also known as decompression sickness, DCI,
or DCS). Susceptibility to DCI may vary substantially from person to
person and from day to day. Neither the IQ-800, nor any dive computer
or table, can guarantee that you will not suffer decompression illness.
Even though you use these items correctly, you may still suffer DCI. Do
not rely on the IQ-800 as your sole means of avoiding decompression
sickness.
WARNINGS

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4. Accessing Display Modes
There are some display modes that the IQ-800 enters and/or exits
automatically. For example, by taking the IQ-800 underwater, you
automatically activate its Dive Mode. Upon surfacing your IQ-800
will automatically enter Time Mode.
To access other modes, you may need to push one of the three
large buttons on the sides of the IQ-800. These are the A, B, and C
buttons. (Fig. 1)
You will find these buttons easy to use. In some instances, you may
need to press a button once and release it to achieve the desired
result. In other instances, you may need to hold the button down
until you get the result you wish. This manual will outline clearly
which procedure to follow for each mode or task.
Throughout this manual display icons that blink are shown
surrounded by gray bars.
Experts recommend divers wait at least 24 hours following any dive
before flying in an aircraft or driving to altitude. Failure to allow
sufficient surface interval before doing so may substantially
increase the risk of Decompression Illness (DCI).
Do not plan dives to depths deeper than those for which the IQ-800 is
capable of displaying an available No-Decompression Limit. Doing so
could cause you to exceed the No-Decompression Limits or limiting
PO2 of 1.6 bar, which may in turn substantially increase your risk of
decompression illness or CNS Oxygen Toxicity and can lead to serious
personal injury or death.
AC
B
E
Figure 1

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5. Time Mode
• Current time: This is the current time of day.
• Current date: This is the current date.
• Current weekday: This is the current day of the week.
• Battery indicator Icon: This displays the current battery voltage. (not
shown)
• PGT (Pressure Gas in Tissue) graph: This indicates the level of
Nitrogen with nine level indicators. The greater the number of
indicators displayed, the greater the pressure of the gas.
• OLI (Oxygen Limited Indicator) graph: This indicates the level of
Oxygen in the diver's body with eight level indicators.
• Nitrox Icon: This Icon is ON when NITROX has been selected.
• Desaturation time (DESAT): This indicates the time remaining until
the body’s internal nitrogen is desaturated. The DESAT is also
displayed if PGT occurs because of a change in the altitude rank.
Time mode is the IQ-800’s default mode. In this mode the screen
displays a minimum of the current date and time of day. Within 24
hours of surfacing from a dive, the IQ-800 will display additional
information while in Time Mode. A description of the screens is
shown below. (Fig. 2,3)
Normal After a dive
Current Weekday
MODE MODE
Current Time
Desaturation Time Surface Time
Figure 2 Figure 3
Do Not Fly

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Warning
Experts recommend divers wait at least 24 hours following
any dive before flying in an aircraft or driving to altitude.
Failure to allow sufficient surface interval before doing so
may substantially increase the risk of Decompression Illness
(DCI).
• Surface time (SURF.T): This is the surface interval time after a
dive. The timer is started from when the depth shown in Dive
mode reaches 5 feet (1.4m) or less. If the depth changes back to
5 feet (1.4m) or more in less than 10 minutes, the previous dive
is continued. Surface time is continued for 48 hours. After that,
surface time is turned off.
• Mode: This display shows the computer in Time mode.
• Don’t Fly Icon: While the computer calculates desaturation time
this icon is displayed during Time Mode. When the computer has
finished calculating desaturation time this Icon is turned off.
Prior to a dive
The letters correspond to the buttons of the IQ-800 shown in figure 1.
• A button: Press this button to move to dive set mode.
• A button held for 2-3 seconds: Moves to time mode.
• B button held down: Time display and backlight comes on.
• C button: Turns on the backlight.
• B+C button: Alarm sound or vibration test.
• E button: Touch this switch and metal housing to switch to dive
mode.
Operation of buttons during Time mode
During a surface interval
• A button: Press to move to dive set mode.
• B button: Time display and backlight comes on.
• C button: Turns on the backlight
• B+C button: Activates the alarm sound or vibration test
• E button: Touch this button and the metal housing to switch to dive
mode.

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6. Dive Set Mode
To enter Dive Set mode from Time mode, press the A button until "D-
SET" is shown on the display.
Note: If the surface interval is less than 10 minutes the computer will
not enter this mode. The computer will switch to dive plan mode.
Use the dive set mode to set the oxygen concentration (FO2), user
safety function (SF), warning alarm sound or vibration (AL-S/AL-V),
and seawater or freshwater (Sea/Fresh) settings. (Fig. 4)
• FO2 (fraction of oxygen): This displays the oxygen concentration
that is currently selected. If the FO2 is set at 21%, "Air" is
displayed.
• PO2 Maximum depth: This displays the PO2 maximum depth (when
PO2=1.4) appropriate for the displayed FO2
• SF (Safety Factor): This displays the SF value set by the diver. The
larger the value, the greater the safety value.
• Alarm operations: The icon will display V for vibrate, or S for sound.
• Nitrox Icon: This Icon is ON when NITROX has been selected.
• Sea/Fresh Icon: This shows whether the computer has been set to
fresh or salt water for depth calculations.
• Mode: Displays “D-SET” when in dive set mode.
Warning Operation
MODE
PO2 Maximum Depth
Dive Set Mode
User Safety Factor
FO2
Figure 4

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Operation of buttons during Dive Set mode.
• Β: Press the B button to select the function you would like to modify.
• C: Use this button to change the value of the selection. If held
down during the FO2 selection the value will scroll rapidly in one
percent increments. The selected alarm will sound for one second
when changing the warning setting. The alarm test will not be
performed if the battery is low.
• E: Touch this button and the metal housing to switch to dive mode.
The computer will enter time mode once the E button is released.
If no buttons are pushed for 2 to 3 minutes, the computer will return to
TIME mode.

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7. Dive Plan Mode
To enter Dive plan mode from Time mode, press the A button until
"PLAN" is shown.
Note: This mode cannot be entered if the computer is in an out of
measurement range lock or a decompression stop violation lock. In
both instances the computer will skip to the dive log mode.
Altitude measurements are not performed in dive plan mode.
By setting the depth and surface time, the no decompression limit
(NDL) for that depth can be calculated. (Fig. 5,6)
The following information is displayed during this mode:
Surface Time: This displays the time currently elapsed since
surfacing and the total surface time needed to return to the selected
depth.
Depth: This displays the desired depth.
NDL: The no decompression limit for the selected depth, based on
surface time, is displayed. The maximum NDL that can be displayed
is 200 minutes. If the selected depth will result in a PO2 greater than
1.4, the display will show bars.
N2: This will display the PGT (pressure gas in tissue) of nitrogen
absorbed in the diver’s body at the set surface time.
O2: This will indicate the level of oxygen in the body during the set
surface time.
Nitrox icon: This icon will be on when the FO2 is set at 22 percent or
higher.

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Mode
NDL (no decompression limit time)
Depth Setting
Depth rank
Operation of buttons during dive plan mode
• A: Use this button to move to dive plan mode. If the button is held
down for 2 to 3 seconds the computer will return to time mode.
• B: Press this button to select either the surface time or depth
setting. Use the C button to change the value of the setting. If the
button is held in, the value will scroll rapidly.
• C: Press this button to change either the surface time value or the
depth value.
• Ε: When water is detected the computer moves to dive mode.
• Auto return: The display automatically returns to time mode when
no buttons are used for 2-3 minutes.
NDL (no decompression limit time)
Surface Time Setting
Mode Figure 5
Figure 6

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8. Dive Log Mode
To enter Dive log mode from Time mode, press the A button until
“LOG” is shown.
Description of the Dive Log functions
The Dive log mode records various data during a dive when the dive
depth is at least 5 feet (1.5m) and the dive time is at least 3 minutes.
Data is recorded during each successive dive, and the log data
storage capacity is about 30 hours of dive time, or up to 60 log data
entries. If the logged dive time exceeds 30 hours or the number of log
data entries exceeds 60, the oldest data is automatically deleted.
The logged data is described below. (Fig. 7,8,9)
.
• Log number: This indicates the number of the log entry being
recorded among the recorded logs.
• Dive date/Dive start time/ Dive end time: This is diving
information. Dive date is the date of the dive. Dive start time is the
time at the start of the dive. Dive end time is the time at the end of
the dive. Both Dive start time and Dive end time are displayed in 24
hour format.
• PGT (Pressure Gas in Tissue) graph: This represents the level of
Nitrogen with nine level indicators at the end of the dive.
• OLI (Oxygen Limited Indicator) graph: This represents the level
of the Oxygen Limit with eight level indicators at the end of the dive.
• Altitude rank: This is the altitude setting used during the dive.
• Nitrox icon: This Icon is ON when NITROX has been used for the
dive
• Fraction of oxygen (FO2): It displays the FO2 which was used
while diving.
• Dive time: This is the dive time.
• Water temperature: Water temperature at maximum depth. The
measurement range is: 23-104°F (-5.0 to 40.0℃). It displays ‘Lo’
when water temperature is under 23°F (-5℃). It displays ‘Hi’ when
water temperature is over 104°F (40.0℃).
• Safety Factor (SF): When the level is "0" the usual algorithm is
used for calculations. When the level is "1" or "2" the next higher
altitude rank is used for the dive calculations. The default setting is
"0".

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• Average depth: This is the average water depth during the dive. If
the depth is over 328 ft (99.9m), the display is ‘---’.
• Maximum depth: This is the maximum depth recorded during a
dive. If the depth is over 328 ft (99m) the display is ‘---’.
• Ascent rate indicator: This is the maximum ascent rate recorded
during a dive.
• Sea/Fresh icon: This indicates the water setting (sea water/fresh
water).
Display 1
Dive number
Log number
Dive date
Display 2
Ascent rate
indicator
No data
Mode
Mode
Water temperature
Maximum depth Fraction of oxygen
Dive end time
Dive start time
Average depth Dive time
Figure 7
Figure 8
Figure 9

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Deco Icon Blinks
Ascent rate warning: If the ascent rate warning is activated it is
recorded in the log. The SLOW icon will blink when the dive log is
displayed. (Fig. 10)
Decompression stop violation: If a deco stop is violated, the
warning is stored in memory and the DECO icon blinks when the log
is displayed.
(Fig. 11)
Warning Displays: These are warnings that can occur during a
dive. For further description of these warnings see the "dive
mode" section.
Alarm Displays
Ιf the following warnings occur during dive mode they are stored in
memory and displayed.
SLOW icon blinks
Figure 10
Figure 11

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OLI warning: If the OLI reaches 8 bars, the warning is stored in
memory and displayed in log mode. (Fig. 13)
OLI Bar Icon Blinks
Decompression dive warning: If the dive enters decompression,
then the warning is stored and displayed during log mode. (Fig. 14)
Deco Icon comes on
PO2 Icon Blinks
PO2 warning: The PO2 icon blinks if the warning was active during
the dive. (Fig. 12)
Figure 12
Figure 13
Figure 14

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Operation of buttons during Log mode
• Α: Press and hold this button for 1-2 seconds to move to time
mode.
• Β: Press this button to change log number.
(1-2→1-1→2-2→2-1→…→60-2→60-1)
• Β: Press and hold this button to change log number using fast
scrolling.
• C: Press this button to change the log number.
(60-1→60-2→…→2-1→2-2→1-1→1-2)
• C: Press and hold this button to change log number using fast
scrolling.
• Ε: When water is detected, the mode moves to dive mode.
• Auto return: The display automatically returns to time mode when
no buttons are used for 2-3 minutes.
Out of Measurement Range warning: If the computer entered out
of range during the dive, then the event is recorded in memory and
the entire display will blink during the log mode. (Fig. 15)
All Segments Blink
Figure 15

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9. Dive History Mode
The IQ-800 records the total number of dives, maximum depth, and
total accumulated dive time in HISTORY mode. (Fig. 16,17)
To enter HISTORY mode from Time mode, press the A button until
the display says “HIST”.
To clear the entire history, press and hold the C button for 5 to 6
seconds. A confirmation sound will occur once the history is reset.
Maximum Water Depth Total Number of Dives
Total Dive Time (hours)
Total Dive Time (minutes)
MODE
MODE
No Data
Bars are shown and
blink
Figure 16
Figure 17

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Description of the Dive Profile mode.
Dive profile mode provides functions for recording various data
during a dive when the dive depth is at least 5 feet (1.5m) and
the dive time is at least 3 minutes. Data is recorded during each
successive dive, and the log data storage capacity is about 30 hours
of dive time (when the profile's sampling time is set at 30 seconds),
or up to 60 log data entries. If the logged dive time exceeds 30 hours
or the number of log data entries exceeds 60, the oldest data is
automatically deleted. (See the section describing profile mode for
further description of log data and profile data.) The logged data is
described below. (Fig. 18)
10. Dive Profile Mode
• Dive date: The date of the dive.
• Dive time: This is the dive time.
• Log number: This indicates the number of the currently displayed
profile data among all of the currently recorded data entries.
• Fraction of oxygen: This shows the Mix value used while diving.
• Sea/Fresh Icon: This indicates the water setting (sea water/fresh
water).
• Mode display: This shows Dive profile mode.
• Battery indicator Icon: This displays the current battery voltage.
• Profile depth: This indicates a maximum water depth value every
30 seconds during the dive. If depth is over 328 ft (99.9m) this
display is ‘---’.
Number of Dives
on that Date
Log Date
Maximum Depth
of Profile Dive Time
Figure 18