Ocean Technology Systems Guardian, Owner'S Manual

Page: 10 / 28

6
Visor, Frame, and Ambient Breathing Valve
®
The Guardian FFM visor is constructed of high strength polycarbonate.
Although scratch-resistant, it is not scratch-proof. Protect the mask when
not diving by storing it in its bag. When diving, minor scratches on the
outside of the visor are difficult, if not impossible, to see due to water filling
the scratch. You should be most concerned with protecting the inside of
the visor from scratches.
The visor is held in place with the visor frame. This frame consists of the
upper and lower visor clamps. Constructed of glass filled nylon, these
clamps are secured by a pair of stainless steel Allen head screws (6-32 x
1”, 7/64” Hex), one on each side of the clamps. The upper visor clamp has
a channel on the back that retains the cable for the left earphone when
using an ear/microphone assembly (part No. 910369-000 w/ Hot-Mic
®
and
910379-000 w/ Super Mic
®
, available separately) for communications. The
lower visor clamp contains the regulator port, regulator “quick-disconnect”
(see Figure 4 on page 7) on the interior of the mask, and the inhalation
vents.
The Ambient Breathing Valve
®
(ABV
®
) is designed to conserve the diver’s
air while on the surface. This is NOT a snorkel. Generally, when diving
with a FFM, the diver is breathing off of a scuba bottle. With the ABV in
the open position and on the surface, the diver is able to breathe ambient
air without removing the FFM. There is a check valve on the inside of the
ABV which allows ambient air to enter the valve only; air is exhaled out
through the regulator. This also prevents air from escaping through the
ABV should it be open underwater.
It is extremely important that the diver’s air supply is turned on prior to
diving. This may seem obvious; however, if the mask (with the regulator)
is put on and the diver is breathing through the ABV, the diver could
unknowingly enter the water without air. Upon surface entry, if positive
buoyancy is not first established, with the diver’s air off, the ABV only
working above water, unable to inflate a BCD or dry suit, the diver could
sink to the bottom with dire consequences.
Danger Note
ALWAYS ensure the diver’s air supply is turned ON prior to entry into the water!
CLOSE THE ABV, test breathe the mask and regulator with at least two full
breaths and watch the submersible pressure gauge! There should be a slight
drop in pressure. This will ensure the diver has the air supply turned on prior to
diving. Add sufficient air to the BCD to have positive buoyancy upon entry. Make
this a matter of routine prior to entry.
Failure to do so can result in serious
injury or death. Ensure clamp screws are in place and securely fastened before
diving. If missing a screw, DO NOT DIVE FFM.