U.S. Divers 150-2421 - Flatfoto 1.3-megapixel Digital Camera, Owner'S Manual, Page: 9 / 63

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Introduction
Congratulations on the purchase of your Monitor 3 Air dive
computer. Our designers have condensed important dive
planning information into a user-friendly dive instrument.
By combining graphics with bold alphanumerics, we have
created an easy-to-use computer that provides dive data at
a glance.
As with all diving equipment, it is important to understand
the features and functions of the Monitor 3 Air. Before
using the Monitor 3 Air, 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.
Section 1 instructs you on preparing the Monitor 3 for its
first use. Section 2 explains all the functions and screen
displays while on a dive. Section 3 shows you how to recall
the dive memory. Instructions on planning a future dive are
given in Section 4. Care & Maintenance tips are covered in
Section 5. Lastly, the reference section contains the
technical specifications and a description of the algorithm.
What is a “Dive Computer”
DEFINITION OF COMPARTMENTS
A dive computer is an instrument that mathematically
simulates the absorption and release of nitrogen by
hypothetical tissue types in the human body. These
hypothetical tissues are commonly referred to as “compart-
ments.” Each compartment absorbs and releases nitrogen
at different rates. The Monitor 3 Air tracks these compart-
ments 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 rectangu-
lar dive profile (figure 1). In reality, however, most recre-
ational 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 multilevel dive profile (figure 2).