Dive Rite NiTek Duo User manual

UserGuide
www.diverite.com
Dateofpurchase:
NiTekDuoDiveComputer
NiTekDuoDiveComputer

Content
NiTek Duo Dive Computer User Manual i
DEVELOPED
BY
Dive Rite
175 NW Washington Street
Lake City, FL 32055
Phone: [phone]
Fax: [phone]
Web: www.DiveRite.com
COPYRIGHT
NOTICE Copyright © 2003-2007 Lamartek, Inc. dba Dive Rite
This manual is copyrighted by Lamartek, Inc. dba Dive Rite. You
may not reproduce, translate, transcribe, or transmit any part of this
manual without express, written permission from Lamartek, Inc.
dba Dive Rite.
WARRANTY
INFORMATION Dive Rite will—at its sole discretion—repair or replace NiTek Duo
components proved to be damaged by faulty manufacture or
material, at no cost, for a period of up to two years from
the date of purchase.
This warranty applies only to the original retail purchaser. It does
not cover commercial or rental use, nor does it extend to units
purchased from other than an authorized Dive Rite dealer.
This warranty specifically excludes battery depletion or other
conditions resulting from misuse, negligence, alteration, accident,
or unauthorized repair.
To make a claim under this warranty, the owner must have
registered his/her warranty using Dive Rite’s website
(www.diverite.com). All warranty repairs (international or domestic)
must be accompanied by a copy of the purchase receipt. For
warranty repairs (international or domestic) the product must be
returned to the store where the item was purchased or directly to
Dive Rite. A Return Authorization must be obtained by calling Dive
Rite corporate offices (386-752-1087) to send items to Dive Rite.
No warranty service will be performed for other than registered
owners. Note: Local dealers and distributors are not responsible for
service of items purchased from unauthorized dealers, internet
dealers, or dealers from other territories.
This warranty becomes void if NiTek Duo components are
damaged by anything other than normal recreational diving use, or
if they have been serviced or repaired by other than authorized
Dive Rite dealers.
Repairs made under this warranty will not extend the warranty
period.
All further claims, especially for damage after diving accidents, are
excluded from coverage under this warranty.
Dive Rite has no obligation to honor any extension of this warranty.
This warranty is in lieu of all other warranties, expressed or implied.
No other person or representative is authorized to assume for Dive
Rite any other liability in connection with the sale of this product.

Content
ii NiTek Duo Dive Computer User Manual
Table of contents
Chapter 1 Introduction • 1
Overview • 2
Features and functions • 3
Specifications • 5
Warnings • 6
Chapter 2 Using the NiTek Duo • 9
Getting started • 10
Accessing display modes and
screens • 11
Time display mode • 12
Dive option set and display mode • 14
Plan mode • 24
Dive computer mode • 26
Gauge mode • 34
Log mode • 36
Profile mode • 38
PC transfer mode • 40
Surface mode (upon surfacing from a
dive) • 41
Altitude operation • 43
Chapter 3 Care and maintenance • 45
Proper handling techniques • 46
Low battery warning • 48
Index • 51

NiTek Duo Dive Computer User Manual 1
Chapter 1
Introduction
Summary
This chapter provides an overview of the NiTek Duo, lists the
NiTek Duo’s features and functions, and covers warning
information that should be read before using your NiTek Duo.
Content Overview • 2
Features and functions • 3
Specifications • 5
Warnings • 6
When diving… • 7

Introduction
2 NiTek Duo Dive Computer User Manual
Overview
Congratulations on your purchase of the NiTek Duo dive
computer. The NiTek Duo is a sophisticated and comprehensive
dive computer that was designed to offer you the latest in dive
computer technology, safety, and reliability.
The NiTek Duo dive computer is a multifunctional computer for
recreational diving, providing information on depth, dive times,
no-decompression and decompression times, and nitrogen and
oxygen absorption and elimination during all dive phases,
including ascent, surface interval times, and subsequent dives.
This information is displayed on an easy-to-read display,
providing simple and direct communication between the diver
and the computer. With an easy-to-read display, the diver has no
problem following and reading the displayed information.
The NiTek Duo comes standard with a number of modes,
including a time mode, dive set mode, dive plan mode, log
mode, profile mode, PC transfer mode, and dive mode.
Note: It is extremely important that you carefully read and
understand this manual. Make sure you fully understand how the
NiTek Duo operates before diving with it.
This manual has been divided into three chapters:
• Introduction: Covers the features and functions,
specifications, and warnings for the NiTek Duo
• Using the NiTek Duo: Covers the operation of each mode
for the NiTek Duo
• Care and maintenance: Covers how to properly care for
and maintain the NiTek Duo and change the battery

Introduction
NiTek Duo Dive Computer User Manual 3
Features and functions
The NiTek Duo incorporates a number of important modes and
features:
• The NiTek Duo turns on automatically upon descent
• On the surface, the NiTek Duo constantly displays a
minimum of date and time
• The NiTek Duo uses easily accessible and highly reliable
push buttons instead of exposed electrical contacts
• The NiTek Duo can be programmed to monitor exposure to
two different gas mixtures during a dive. Mix1 is
programmable for mixtures ranging from air (EAN21) to
EAN50. Mix2 is programmable for mixtures ranging from
air (EAN21) to EAN99. Underwater, NiTek Duo users can
switch between mixes at the push of a button.
• The NiTek Duo is capable of functioning up to a depth of
328 feet (100 meters) when in dive computer mode and 656
feet (200 meters) when in gauge mode
• The NiTek Duo automatically adjusts for altitudes up to
19,685 feet (6,000 meters)
• The NiTek Duo displays a variety of data underwater
including: date, time of day, current and maximum depths,
no-decompression dive time elapsed and remaining, and
water temperature
• The NiTek Duo displays data specifically related to the use
of Enriched Air Nitrox (EANx) including: fraction of
oxygen (FO2) setting, partial pressure of oxygen (PO2), and
an oxygen limit index (OLI) representing the cumulative
effect of a diver’s exposure to elevated PO2s (the theoretical
“CNS clock”) as a bar graph
• Through a combination of audible and visible alarms, the
NiTek Duo helps to alert the diver to a number of possibly
hazardous situations including: violation of ascent rate, no-
decompression state, and whether mandatory decompression
stops are necessary or if the diver has ascended above a
mandatory stop ceiling. Nitrox specific warnings occur when
the diver approaches or exceeds a limiting PO2 of 1.4

Introduction
4 NiTek Duo Dive Computer User Manual
atmospheres for mix1 and 1.6 atmospheres for mix2, and
when cumulative exposure to elevated PO2s exceeds
recommended limits.
• The NiTek Duo can calculate decompression stop
requirements for stops as deep as 90 feet (27 meters)
• The NiTek Duo can be programmed to display data in
Imperial or metric units
• Dive depth can be displayed in fresh or salt water
equivalents
• Special mode indicators make it easy to determine what
display mode or screen you are in at any time
• The NiTek Duo has a back light to illuminate the screen,
which can be turned on with the touch of a button
• The NiTek Duo’s memory capability enables it to hold and
display log data on up to 30 hours of dive time or 60 dives
• Detailed dive-profile information can be stored for each dive
through user-programmable sample intervals of 15 or 30
seconds (longer intervals allow data for a greater number of
dives)
• Dive data can be uploaded and stored in a dive log format on
a desktop or laptop computer using the NiTekLogic™
software and optional PC interface

Introduction
NiTek Duo Dive Computer User Manual 5
Specifications
Algorithm: Buhlmann ZH-L16
Sample tissues: 9
Tissue half-lives: from 5 to 640 minutes
Size and weight
Diameter: 2.5 in (62 mm)
Height: 1.0 in (25 mm)
Weight: 4 ounces (115 g)
Display face
Backlight illumination
Low battery indicator
Three user buttons
Water immersion switch
Depth sensor
Sea or fresh water calibration
Measuring range: 0 to 328 feet (0 to 100 m) measured every second
(Gauge mode 656 feet (200 m)
Accuracy: +/- 3% + 2 feet (0.5 m)
Surface interval time: from 0 to 48 hrs
Diving time: from 0 to 599 minutes
Ascent rate warning: 26 to 52 feet per minute (8 to 16 m)
Thermometer
Measuring range: 23 °F to 104 °F (-5 to 40 °C)
Accuracy: +/- 4 °F (2 °C)
Measurement interval: Every minute
Clock
Accuracy: +/- 30 sec on average per month
24-hour display
Altitude
Altitude function monitoring: from 0 to 19,685 feet (6,000 m)
measured every 10 minutes
Accuracy: +/- 800 feet (250 meters)
Battery
Li/MnO2 CR 2032 3V button battery
Average battery life: About 3 years (50 dives/year)
Replacement: User replaceable or return to manufacturer
Breathing gas
Mixes: 2 gas settings
O2 setting range: Mix1 21 to 50 percent, Mix2 21 to 99 percent
O2 setting: 1% increments
Dive log
Dive logging: Maximum of 60 dives
Profile logging: Maximum of 30 hours
Profile sampling rates: 15 or 30 seconds

Introduction
6 NiTek Duo Dive Computer User Manual
Warnings
This information has been developed for your safety. Please read
and understand this manual completely before using your NiTek
Duo dive computer.
Important safety information:
• Before using your NiTek Duo, it is extremely important that
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.
• The NiTek Duo is designed for use by certified 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 these qualifications and thus, may not be
able to identify, assess, and manage the risks scuba diving
entails. Use of the NiTek Duo in conjunction with Enriched
Air Nitrox (EANx) requires that divers be trained and
certified for Nitrox diving.
• The NiTek Duo is not intended for use by commercial or
military divers whose activities may take them beyond the
commonly accepted depth limits for recreational or technical
diving.
• Although the NiTek Duo is capable of calculating
decompression stop requirements, users must remember that
dives requiring mandatory stage decompression carry
substantially greater risk than dives made well within no-
decompression limits.
• The NiTek Duo is designed for use by one diver at a time.
Divers should not share a single NiTek Duo—or any other
dive computer—on the same dive. Additionally, no diver
should lend their NiTek Duo to anyone else until it
calculates that no measurable residual nitrogen remains after
previous dives and no longer displays the “desaturation
time” indicator while in time mode. Further, no diver should
use their NiTek Duo for repetitive dives—unless that same
properly functioning NiTek Duo has accompanied them on

Introduction
NiTek Duo Dive Computer User Manual 7
all previous dives in the same repetitive dive series and is
thus, accurately monitoring the diver’s total exposure to
oxygen and nitrogen.
• Neither the NiTek Duo—nor any other dive computer—
physically measures the amount of nitrogen present in body
tissues or the rate at which nitrogen is being absorbed or
released. The NiTek Duo 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 (DCI) are assumed to
absorb and release nitrogen from body tissues. Thus, the
NiTek Duo 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 NiTek Duo—and other dive computers
or dive tables—with even greater caution.
• Little is known 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 NiTek Duo—nor any other dive table or
computer—can guarantee that you will not suffer
decompression illness. Even though you use these items
correctly, you may still suffer DCI. Use your NiTek Duo
conservatively and in conjunction with other dive planning
devices, such as dive tables. Do not rely on the NiTek Duo,
or any similar device, as your sole means of avoiding
decompression illness.
When diving…
• Do not “push” the no-decompression limits (NDLs). Make
safety stops before ascending. If you exceed the no-
decompression limits, check your breathing gas supply at all
stop depths.
• The NiTek Duo does not monitor breathing gas supply. You
must monitor this yourself, on every dive, using a
submersible pressure gauge or equivalent device.

Introduction
8 NiTek Duo Dive Computer User Manual
• Do not rely solely on this or any other dive computer. Take a
back-up dive computer or dive tables (along with a separate
means of monitoring depth and dive time).
• Be aware that the NiTek Duo makes assumptions regarding
residual nitrogen based on altitude settings. Avoid making
abrupt changes in altitude following a dive, as doing so may
be very dangerous.

NiTek Duo Dive Computer User Manual 9
Chapter 2
Using the NiTek Duo
Summary
This chapter provides topics about using, setting, and
understanding each of the modes and options of the NiTek Duo.
Content Getting started • 10
Accessing display modes and screens • 11
Button operation • 11
Time display mode • 12
Setting the time and date • 12
Entering time display mode from another
mode • 13
Activating the back light • 13
Dive option set and display mode • 14
Using computer mode • 14
Setting Mix1 and Mix2 percentages • 15
Setting the safety factor • 16
Setting the dive profile sampling rate • 17
Setting for fresh or salt water use • 18
Setting the maximum depth alarm • 18
Setting the dive time alarm • 19
Setting the computer for metric or Imperial
operation • 19
Understanding FO2 default • 20
Using gauge mode • 22
Plan mode • 24
Dive computer mode • 26
Primary underwater screen • 26
Secondary underwater screen • 27
Changing gas mixes underwater • 28
Safety stop indication • 28
Warnings while in diving mode • 29
Gauge mode • 34
Log mode • 36
Profile mode • 38
PC transfer mode • 40
Before transferring the dive log • 40
Surface mode (upon surfacing from a dive) • 41
Altitude operation • 43

Using the NiTek Duo
10 NiTek Duo Dive Computer User Manual
Getting started
The NiTek Duo has many modes and screens and a number of
options that can be changed depending on your dive location and
profile. The following is a checklist of general things that you
should pay attention to before, during, and after a dive.
Before a dive
• Check that the proper time and date are set. If you traveled,
your NiTek Duo may be set to your home time zone.
• Check that the proper mixes are set for mix1 and mix2. If
you are using gauge mode, make sure it is set to “gage.”
• Make sure that you review the dive plan mode for maximum
depths and times for the mixes you are using
During a dive
• Monitor the NiTek Duo throughout your dive for depth and
time
• Monitor the N2 and O2 loading bar graphs
• Pay attention to any alarms, such as an ascent rate warning
• Follow the no-decompression limits or complete the required
decompression displayed and perform the necessary safety
stop
After a dive
• Monitor surface interval time if making another dive
• Follow the no-fly requirements
• Review your dive using the log mode and profile mode
• Download the dive log to your PC if you have the optional
PC interface

Using the NiTek Duo
NiTek Duo Dive Computer User Manual 11
Accessing display modes and screens
There are some display modes that the NiTek Duo enters and/or
exits automatically. For example, by taking the NiTek Duo
underwater, the dive mode automatically turns on. Upon
surfacing, the NiTek Duo automatically enters the time mode.
Accessing other modes or screens requires the use of the NiTek
Duo’s buttons.
Button operation
The NiTek Duo has three buttons (select, mode, and set), which
are used to access the different modes and screens. To use the
buttons, simply press the button once or hold the button down
depending on what you are trying to do. The correct procedure to
use is clearly defined in each topic throughout the manual.
• Select button: This button is used to select the option field
that you want to change
• Mode button: This button is used to select and scroll through
the different modes, such as time mode
• Set button: This button is used to set an option’s setting,
such as setting the date
Select SetMode
The front of the NiTek Duo, showing the three buttons that are
used to access and setup the different modes and screens

Using the NiTek Duo
12 NiTek Duo Dive Computer User Manual
Time display mode
Time display mode is the NiTek Duo’s default mode. The
computer returns to this mode automatically upon surfacing from
a dive and from other modes when a period of time has passed
without any buttons being pressed.
1
2
34
In time display mode, “time” (1) is displayed at the bottom of the
screen, and the date (2) and time (3) with seconds (4) are
displayed. Time can also be displayed in 24-hour (military) time.
The NiTek Duo may display additional information concerning
exposure to nitrogen and oxygen, desaturation time, surface
interval time, and altitude. These items are covered in “Surface
mode” and “Altitude operation.”
Setting the time and date
Setting the time and date are done in the time set mode. You can
enter or change the year, month, day, hours, minutes, and
seconds in this mode.
To set the time and date:
1. Press Mode until “set” is displayed in the “time” position.
The “seconds” field flashes.
2. Press Set to “00” the seconds or press Select to go to another
field, such as minutes.
3. Using Select and Set, set the year, month, day, hour,
minutes, seconds, and whether you want the time displayed
in 24-hour format.

Using the NiTek Duo
NiTek Duo Dive Computer User Manual 13
For example, 1:00 PM would be 13:00.
4. Press Mode.
The computer returns to the time display mode.
Entering time display mode from another mode
When you are using other modes, it is very easy to return to the
time display mode.
To enter time display mode from another mode:
1. Press and hold Mode for two seconds.
—OR—
2. Press Mode until “time” is displayed.
Activating the back light
The NiTek Duo has a back light that illuminates the screen.
To activate the back light:
1. Press either the Select or Set button.
The back light illuminates for four to five seconds.
2. Press either button again to reactivate the back light.

Using the NiTek Duo
14 NiTek Duo Dive Computer User Manual
Dive option set and display mode
Dive option set and display mode is where all “dive” option
settings are displayed and set up. There are two screens needed
to view and set up all dive options.
Using computer mode
Computer mode is when the NiTek Duo is operating in the
normal computer mode. “Dive” is displayed on the screen and all
computer mode functions operate normally. The NiTek Duo dive
option set and display mode is used to review and change option
settings that pertain to an upcoming dive. The operating depth
limit when in computer mode is 328 feet (100 meters).
12
3
1
5
4
10
2
11
13
Dive option display and set fields for screen one
79
6 8
Dive option display and set fields for screen two
• (1) Dive operation
• (2) Mix1 and mix2 FO2 gas percentages
• (3) Dive safety factor

Using the NiTek Duo
NiTek Duo Dive Computer User Manual 15
• (4) Dive profile sampling rate
• (5) Salt or fresh water use
• (6, 7) Maximum depth alarm
• (8, 9) Maximum time alarm
• (10) Metric or Imperial units of measurement
There are three “display only” option fields that change based on
how the above settings are set.
• (11) Nitrox indicator: “Nitrox” is displayed if mix1 is set for
a FO2 of greater than 21 percent. If mix1 is set for 21
percent (air), nothing appears. If mix1 is in “default,” the
Nitrox indicator flashes. For more information on “default,”
see “Understanding FO2 default.”
• (12) Maximum operating depth (MOD) for FO2 setting: This
is the safe operating depth (maximum) for the selected mix.
These are based on limiting PO2 factors of 1.4 or 1.6
atmospheres respectively.
• (13) Maximum depth and time alarm indicators: When you
see an indicator symbol, the alarm is set to on.
Max depth symbol:
Max time symbol:
To enter dive operation:
1. Press Mode until “dive” is displayed.
2. Using the topics that follow, set up your desired dive option
settings.
3. If you want to exit dive mode, press and hold Mode for 1 to
2 seconds to return to time mode.
Setting Mix1 and Mix2 percentages
You must set the breathing mix you plan on using on your dive.
Mix1 is considered the first breathing gas you plan on using
during a dive, and mix2 is considered the second breathing gas
you are using on a dive.
• Mix1 can be set for 21 to 50 percent oxygen
• Mix2 can be set for 21 to 99 percent oxygen

Using the NiTek Duo
16 NiTek Duo Dive Computer User Manual
Note: If you only plan on using one mix on your dive, you only
need to set mix1.
To set mix1 and mix2 percentages:
1. Press Mode until “dive” is displayed and flashing on the
screen.
2. Press Select to select the mix1 field.
3. Press and release Set to increase the percentage.
Press and hold Set to advance the percentages rapidly. The
percentage will stop at 32 percent and again at 50 percent.
4. Press Select to advance to mix2.
5. If you are entering a percentage for mix2, press and release
Set to increase the percentage. If you are not setting a
percentage for mix2, press Select to advance to the safety
factor setting.
Press and hold Set to advance the percentages rapidly. The
percentage will stop at 21 percent and again at 32 percent.
6. When finished, press Select to advance to the next option
(safety factor) or to exit, press and hold Mode for 1 to 2
seconds to return to time mode.
Setting the safety factor
The safety factor setting is used to add an additional safety
margin to the no-decompression limits and decompression stop
times. There are three possible settings, 0, 1, and 2. A higher
setting results in shorter no-decompression limits and longer
decompression stop times.
Setting Description
0 Calculations are based solely on its built-in algorithm
(Buhlmann ZH-L16)
1 Calculations are based on one altitude rank higher
than the dive was actually made
2 Calculations are based on two altitude ranks higher
than the dive was actually made