Daewoo MATRIX User Manual

MATRIX MANUAL

Safety Considerations

You must carefully read this entire manual before using your Matrix.

WARNING: Diving has many inherent risks. Decompression
sickness is among the most serious of those risks. Even if you
follow the instructions in this manual carefully, it is possible
that you may be seriously injured or die from decompression
sickness, or some other inherent risk of SCUBA diving. Unless
you are fully aware of these risks and are willing to personally
accept and assume responsibility for those risks, do not use the
Matrix!

The Matrix is a sophisticated decompression tool to assist a trained and certified
SCUBA diver in making decisions concerning dive planning and execution. As with any
tool, the Matrix may be misused if the following safety and operational precautions are
not strictly followed. If they are followed, careful use of the Matrix can increase your
diving enjoyment and reduce the risk of decompression sickness; if they are not
followed, you will be placing yourself at serious risk for decompression sickness.

The Matrix is a technically advanced tool based on a biophysical model of decompression theory. However, neither it nor
any other diving computer (or table) can actually monitor the physical changes that occur in your body as you dive. Each
diver varies in his or her susceptibility to decompression sickness, and that susceptibility may vary from day to day .
Decompression modeling is an inexact science; it is based, at least partly , on certain unproven assumptions. Therefore,
you must dive responsibly and to carefully follow all standard safe diving practices as well as the warnings and cautions
contained in this manual.

Pay special attention to

warnings and cautions, which

are denoted by this symbol

WARNINGS are used before a
procedure or situation that may
result in serious injury or
death.
CAUTIONS are used before
any situation or technique that
will result in damage to the
product.

Guidelines for Using the Matrix

The following guidelines for using the Matrix are derived from the latest medical research and the recommendations of
the American Academy of Underwater Sciences for diving with dive computers. Following these guidelines will greatly
increase your safety while diving, but cannot guarantee that decompression sickness will not occur.

1. In accordance with the recommended maximum diving limit of all instructional agencies, do not dive deeper than
130 feet (40 meters).

2. Do not use the Matrix for planned decompression diving. The decompression algorithm contained in the Matrix
should be used only for emergency or unintended decompression.

3. On all no-decompression dives with the Matrix, make a safety stop for three to five minutes between 10 and 30
feet (3 and 12 m) before surfacing.

4. Never use the Matrix for repetitive, “square” dives deeper than 60 feet (18 meters). A square dive is a dive that is
performed for its duration at a uniform depth.

5. Always make the deepest dive of the day first when repetitive dives are planned, and for each successive dive make
sure that the deepest portion of that dive is done at the beginning of the dive.

6. The Matrix is designed for dives made with compressed air only. Do not use the Matrix for dives made with nitrox or
other mixed gases.

7. All divers using dive computers to plan dives and indicate or determine no-decompression/decompression status
must use their own computer.

8. If the Matrix fails at any time during the dive, the dive must be terminated and appropriate procedures (including a
slow ascent and a 3 to 5 minute safety stop) should be initiated immediately (see page 38).

9. On any given dive, all divers in a buddy group must follow the most conservative dive computer for that particular
dive.

10. Do not dive for 24 hours before using the Matrix for the first time.

11. You MUST follow the ascent rates as indicated by the Matrix. If the computer fails, ascend to surface no faster than
60 ft/min (18 m/min).

12. You MUST be familiar with all signs and symptoms of decompression sickness before using the Matrix! Seek
IMMEDIATE treatment for decompression sickness should any of these signs or symptoms occur after a dive! There
is a direct correlation between effective treatment and the delay between the onset of symptoms and the treatment
for decompression sickness.

13. Always observe the optical alarm signals of the Matrix. Avoid situations of increased risk for decompression sickness
which are marked with a warning sign in this manual.

14. Never dive the Matrix to its limits, as well as other dive computers and tables. Give yourself a margin of safety by
always leaving a few minutes of no-stop time before making an ascent.

15. Avoid repeated ascent and descents (yo-yo diving) while using the Matrix.

16. DO NOT perform repetitive decompression dives. Doing so greatly increases the risk of decompression sickness.

17. Carefully inspect your Matrix computer for any signs of damage or malfunction before every dive.

Introduction

Congratulations on the purchase of your Matrix dive computer. Our designers have condensed all the crucial dive
information into a user-friendly dive instrument. By combining a color-coded system with bold alphanumerics, we have
created an easy-to-use computer that provides dive data at a glance.

As with all life support diving equipment, it is crucial to understand the features and functions of the Matrix. Before
using the Matrix, it is essential to read this manual in its entirety . Contained within this easy to read manual are illustra­tions to aid you in the complete understanding of the computer.

This manual covers both the imperial and metric versions of the Matrix. Where applicable, two illustrations are used - an
imperial version and metric version.

Chapter 1 covers all the operating instructions, including attaching the computer to the regulator. Chapter 2 is dedicated
to diving conditions that U.S. Divers considers extreme, or are past the operational limits of the Matrix. Chapter 3 offers
advise on care and maintenance, and instructions on changing the battery . Lastly, the reference section contains the
technical specifications and glossary .

WHAT IS A “DIVE COMPUTER”

Definition of Compartments

A dive computer is an instrument that mathematically simulates the absortion
and release of nitrogen by hypothetical tissue types in the human body. These
hypothetical tissues are commonly referred to as “compartments.” Each
compartment absorbs and releases nitrogen at different rates. The Matrix tracks
these compartments constantly , providing you with up-to-the-minute decom­pression information.

Multi-Level Diving

If you use, or have used, dive tables you know the total amount of time you can
stay under water is based on the maximum depth reached during the dive. Dive
tables, such as the U.S. Navy dive tables, assume that you immediately
descend to a single depth, stay at that depth for the duration of the dive, then
immediately surface from that depth. This type of dive profile is referred to as a
rectangular dive profile (figure 1). In reality , however, most recreational divers go
to the deepest depth first and make a gradual ascent to the surface. This type
of dive profile is referred to as a multi-level dive profile (figure 2).

Multi-level diving is where the Matrix excels. By continuously calculating the
nitrogen absorption/release of all the compartments, the computer updates the
amount of no-decompression time (NDT) you have left. As you ascend to
shallower depths, the computer credits you with more allowable NDT; if you go
deeper, it reduces the NDT available.

Diving Responsibly

Years of research and thousands of dives have gone into the mathematical
formulas used by the Matrix. However, the computer does not have special
sensors attached to your body; it doesn’t know if you are tired, dehydrated,
overweight, or out of shape. For this reason, U.S. Divers recommends that you
never push the no-decompression limits of the computer. Always leave a
comfortable safety margin in respect to no-decompression time and ascent
speed. Let the computer assist you in making a safe dive. Do not let it control
your dive.

WARNING: Using the Matrix will not prevent the possibility
of decompression sickness, but using it sensibly reduces
this risk. Any sport diver, however, must accept that there
is no device or procedure which will totally prevent the
possibility of a decompression accident.

Figure 1

Rectangular Profile

Figure 2

Multi-Level Profile

Operating the Matrix

ATT ACHING THE MA TRIX TO Y OUR REGULA TOR

If you have purchased the Matrix in the Pivot® console, have your Authorized U.S. Divers Dealer attach the console to
your first-stage regulator. If this is not possible, follow the steps below to do it yourself:

1. Remove the high pressure (HP) port plug from your first-stage regulator using the appropriate wrench. The HP port
on all U.S. Divers first-stage regulators is clearly marked with the letters “HP.”

7

Note: The end fitting of the HP hose has
this is the case with your regulator, you need to purchase a 7/16" female to 3/8" male adapter (U.S. Divers part
number 1017-85) from your U.S. Divers dealer.

2. Thread the end of the HP hose into the HP port of the first-stage until finger tight. Using a
tighten the hose fitting until snug. DO NOT overtighten.

3. Attach the first-stage to a charged SCUBA cylinder. Slowly turn the valve handwheel counterclockwise until the valve
is fully open. Submerge the first-stage in water and check for any leaks. If you detect leaks, take your regulator and
computer to your U.S. Divers dealer and have the O-ring inspected and/or replaced. Then have the U.S. Divers
dealer attach the Matrix to your regulator.

STARTUP/DIAGNOSTIC MODE

Starting the Matrix

T o activate the Matrix, simply press and release the neon-yellow button (figure 3,a). After
pressing the button, the Matrix displays all “8”s followed by dashes, followed by all the
digits counting down from 9 to 0. During this countdown, the Matrix goes through a self­diagnostic test to check all its functions, battery power and barometric pressure (alti­tude).

After the Matrix completes it diagnostics, it goes into Surface Mode and is ready to make
a dive. If you do not make a dive within two hours after turning on the Matrix, the
computer will turn off automatically . Always be sure to check to see if the unit is activated
before entering the water.

WARNING: Never activate the Matrix while underwater. This may
result in inaccurate depth and no-decompression time displays.
Activation is not possible deeper than ten feet.

/16" threads. On some early model first-stages, the HP port is only 3/8". If

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/8" open-end wrench,

Figure 3

Startup/Diagnostic Mode

Low Battery Warning

If the Matrix detects low battery power, the battery warning icon appears (see figure 4,a).
If the battery icon remains flashing on the screen after startup, you have enough power to
complete one day of diving. If you intend to do multi-day diving, replace the battery
immediately.

WARNING: If the low battery icon appears, U.S. Divers strongly
recommends that you DO NOT dive until you change the battery .
Although there may be enough power to finish a full day of diving,
sudden changes in temperature can cause the battery voltage to
drop below the operational level, causing the computer to shut off.

WARNING: DO NOT change the battery between dives, or between
days of diving. Once the battery is removed, all residual nitrogen
information is erased. When the Matrix is activated after new
batteries have been installed, the computer assumes you are on
the first dive of the first day of a multi-day trip. This means the
computer may allow you more no-decompression time than you
really have, resulting in a greater chance of decompression
sickness.

Figure 4

Low Battery Display

Altitude Diving

The mathematical model in the Matrix accounts for the reduced no-decompression time available at higher elevations
based on the National Oceanic and Atmospheric Administration (NOAA) guidelines. When diving in high altitude lakes or
rivers (from 3,000 to 14,000 ft; 915 to 4267 m), the Matrix automatically adjusts to these conditions providing correct
depth and reduced no-decompression times. At altitudes over 3,000 ft (915 m), depth calibration automatically
changes to read in feet/meters of freshwater (FFW, MFW) instead of feet/meters of seawater (FSW , MSW).

WARNING: Until it has shut itself off, you must not use the Matrix at an altitude other than
the altitude where it was originally activated. Doing so will result in an error equal to the
difference in barometric pressure, and possibly a false dive mode.

SURFACE MODE

The Matrix enters Surface Mode when (1) the computer completes the startup/
diagnostic procedures, or (2) ten minutes after completing a dive deeper than 5 feet,
or 1.5 meters. While in Surface Mode, the Matrix alternates between the following
three informational displays:

1: Standard surface information

2. Pre-dive planning sequence

3. Wait-to-fly time

Standard Surface Information

The first display to appear in Surface Mode is standard surface information (figure 5).
This display gives the following information:

a. Surface Time. Notice how the wave icon is below the time display, meaning that

it is “time above the water.” The time is displayed in HH:MM

b. Dive number. The computer displays the number of the dive just completed. After

startup, this number will be 0. The Matrix counts up to 10 dives. After dive 10, it

cycles back to 1.
c. Depth. Depth always shows 00 ft., or 0.0 m during Surface Mode.
d. Compartment Loading Bar Graph (CLBG). The CLBG is only displayed after

making a dive. During the surface interval, the CLBG starts to recede, indicating

that you are off-gassing nitrogen. When you first turn on the Matrix, you will not

see the CLBG.

Wait-to-fly Time

The second display to appear during Surface Mode is wait-to-fly time (figure 6). It
appears about twenty seconds after the standard surface information, and only
appears after a dive. Only two elements appear: (a) the no-fly icon (airplane icon) and
(b) the wait-to-fly time.

Wait-to-fly time starts to count down from 23:50 (24 hours less the first 10 minutes of
surface interval). At the 12:00 mark, the Matrix shuts down internally , but continues to
display the countdown from 11:59 to zero. Therefore, if you want to make a dive while
wait-to-fly time is 12 hours or less, you must first reactivate the computer by pressing
the neon-yellow button.

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Wait-to-fly guidelines

■

■■

In 1990, the Undersea and Hyperbaric Medical Society (UHMS) published a set of

guidelines for lowering the chance of decompression sickness due to flying too

soon after diving. The UHMS suggests divers using standard air tanks and exhibit-

ing no symptoms of decompression sickness wait 24 hours after the last dive to fly

in an aircraft with an internal cabin pressure of 8,000 feet (2438 m) or less. The

only two exceptions to this recommendation are:

Imperial

Figure 5

Standard Surface mode

Figure 6

Wait-to-fly Time