Product Certifications; Limited Warranty And Liability Statement; User & Environmental Adaptation - Cochran EMC-20H Owner's Manual

THE WARRANTY AND REMEDIES SET FORTH ABOVE ARE
EXCLUSIVE AND IN LIEU OF ALL OTHERS, WHETHER ORAL OR
WRITTEN, EXPRESSED OR IMPLIED. COCHRAN UNDERSEA
TECHNOLOGY SPECIFICALLY DISCLAIMS ANY AND ALL IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.
No Cochran Undersea Technology dealer, agent, or employee is
authorized to make any modification, extension, or addition to this
warranty.
USER & ENVIRONMENTAL ADAPTATION: The EMC-20H is one of the
new breed of Dive Computers that adapts its algorithm to the users diving
environment and style as originally pioneered by COCHRAN. All of
COCHRAN's newer dive computers incorporate this capability. The
factors that are used for this "Adaptation" in the EMC-20H are:
Water Temperature Salt/Fresh Water Compensation
Microbubble Altitude Acclimatization
User Conservatism Previous Dive Profiles
WATER TEMPERATURE: Diving in cold water can lead to a lower diver
core and skin temperature which can affect the gas exchange rate of the
body's tissues. The EMC-20H features two modes of Temperature
Compensation, Normal or Reduced. The EMC-20H progressively makes
its nitrogen algorithms more conservative as the water temperature
declines below 75 degrees F. Above this water temperature, there is no
temperature compensation. In the Reduced Mode, the algorithms are
made more conservative by approximately one-half the amount of the
Normal Mode. If the diver is wearing an insulated dry suit and is relatively
warm even in cold water, this temperature compensation factor may be
set to Reduced Mode at the divers discretion using the Analyst
software.
MICROBUBBLE: There are several theories regarding the exact method
by which a nitrogen bubble forms from a microbubble, which was formed
from micronuclei. Currently the predominant theory states that more
rapid ascents accelerate bubble formation. The EMC-20H comprehends
and adjusts for this phenomenon.
USER CONSERVATISM: Current dive computers cannot tell if the diver
is dehydrated, tired, smokes, overweight, or has some other physical
issue that may require additional conservatism in the nitrogen algorithm.
The EMC-20H allows the diver to input an added degree of conservatism
to the nitrogen algorithm from 0 to 50 percent in one-percent increments.
This can be done via the Touch Contact Programming Mode or with the
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Analyst Personal Computer Interface.
PREVIOUS DIVE PROFILES: Under some circumstances, recent dive
activity can have an effect on nitrogen loading, particularly if the diver
engages in inverted profile diving. This occurs when a deep dive is
followed by an even deeper dive. This recent dive history is used to
compensate the nitrogen loading for the current dive. This can be
enabled or disabled with the Analyst
SALT/FRESH WATER COMPENSATION (High/Low Water
Conductivity): There is approximately a three percent difference in depth
readings taken in salt water versus fresh water. Some dive computers
are calibrated in feet of fresh water and some are calibrated in feet of
seawater. Diving in a medium different from what the dive computer is
calibrated for will cause apparent depth errors. Only COCHRAN dive
computers, including the EMC-20H, actually determine the type of diving
medium and compensate the depth reading accordingly. This is
accomplished by measuring the conductivity of the water during a dive.
Caution must be taken in interpreting this reading since some apparent
fresh water is actually high in minerals or contaminants and is correctly
compensated as salt water (High Conductivity). This commonly occurs in
some caves, springs, and lakes.
ALTITUDE ACCLIMATIZATION: Driving or flying to a dive site
significantly higher in altitude requires special modifications to the "sea
level" algorithm. The EMC-20H regularly samples the ambient
barometric pressure to determine these changes in altitude whether the
unit is On or Off. Accordingly, the decompression algorithm is changed
to reflect these barometric pressure changes. Note that temperature and
weather systems also affect barometric pressure and hence, apparent
altitude. Using the Time-To-Fly digits, the number of hours required to
"adapt" to the new altitude is immediately known to the diver. If a
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PC
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Personal Computer Interface.
significant altitude change occurs, a minimum of one hour should pass
before diving to allow the unit to adapt to this new altitude. Rapid
changes in altitude should be avoided. The dive computer may interpret
a rapid change from a higher altitude to a lower altitude as a dive.
Should this occur, removing the batteries for ten minutes will reset the
computer, however, all tissue nitrogen loading will also be lost.
Should it be desired to initiate a dive PRIOR to completing the adaptation
time, the EMC-20H will treat this dive as a repetitive dive in its algorithm,
taking into account the "residual" nitrogen present due to travel to
altitude. There are two methods of compensating for altitude. Via the
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Analyst PC Interface, ZONE or SEAMLESS altitude compensation may
be selected.
In ZONE all altitudes less than 2,000 feet above sea level use the sea-
level algorithm. At altitudes greater than this, altitude compensation is
"seamless"; literally, every small fraction of gained altitude is considered
in adjusting the algorithm. ZONE will reduce the occurrences of obtaining
slightly different altitude readings and corresponding no-decompression
(NDC) limits when diving within a given area. However, ZONE reduces
the accuracy of the altitude compensation for the first 2,000 feet above
sea level, since all altitudes below 2,000 feet are treated as sea level.
The advantage in ZONE is that changes in apparent altitude due to
temperature or weather changes at sea level will not affect the NDC
computations.
In SEAMLESS, the algorithm is adjusted for extremely small changes in
altitude. However, a difference in altitude may be seen from day-to-day
at a given dive site due to temperature or weather systems and their
effect on barometric pressures. SEAMLESS will provide the most
accurate altitude compensation algorithm, but normal variations in
atmospheric barometric pressure may affect the no-decompression time
which is more predominantly seen in the Pre-dive Prediction forecast.
CAUTION: The EMC-20H will not perform Altitude Acclimatization if
the touch contacts are shorted or bridged. Rinse the unit with
clean fresh water and dry it with a towel after each dive.
Transporting and storing the unit in its case will help prevent
the possibility of the contacts being shorted or bridged.
WARNING: While the EMC-20H will automatically adjust its no
decompression algorithm for altitude, you should NOT attempt
to dive at altitudes greater than 1,000 feet above sea level
without first completing a sanctioned altitude diving course
from a recognized training agency for recreational diving. The
EMC-20H should not be used for this type of diving by anyone
without this important training.
METRIC/IMPERIAL MODES: If the computer is computing and
displaying in Metric, the "METRIC" legend will be illuminated when the
computer is on. Metric/Imperial selection is made using the Analyst
software. Changing Modes does not affect any profiles or data stored in
the computer.
LOW BATTERY INDICATIONS: Fresh batteries should read about 3.2
volts on the Information Screen. When the battery voltage drops to 2.5
volts, the "BATT" legend will be illuminated. It is recommended to
change the batteries at this point, but several dives might still remain
possible. When the battery voltage decays to 2.2 volts, the "BATT"
legend will begin to flash on and off. Once the "BATT" legend begins to
flash the TACLITE™ is deactivated, to conserve the remaining battery
power even though the unit may be on a dive, and can not be activated
until fresh batteries are installed. While there should be sufficient battery
power to normally complete a dive, it is not recommended to begin a new
dive until fresh batteries are installed. After the computer automatically
turns itself off 70 minutes after a dive, it cannot be turned back on if the
battery voltage is less than 2.0 volts. Fresh batteries must be installed.
See the "BATTERY CHANGES" section of this manual for detailed
information on how to change batteries.
CAUTION!!! COMPLETE LOSS OF BATTERY POWER MAY CAUSE
ALL PREVIOUS DIVE NITROGEN LOADING TO BE LOST. THIS WILL
AFFECT NITROGEN CALCULATIONS ON NEAR-FUTURE DIVES.
AFTER A BATTERY CHANGE, CONFIRM THAT NO-
DECOMPRESSION TIME DATA IS REASONABLE IN THE PRE-DIVE
PREDICTION MODE. DIVE-OF-DAY NUMBER GOING TO ZERO
IMMEDIATELY AFTER CHANGING BATTERIES IS ANOTHER
INDICATION OF A LOSS OF NITROGEN LOADING.
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