Cochran EMC-14 User manual

www.divecochran.com
Cochran
EMC-14
Owner's Manual
English - Metric
Ver: EMC-14m -1.50
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1
PRODUCT INTRODUCTION: The EMC-14 is quite simple to use and
operate, but underneath that simplicity lies a significant level of
sophistication. To get the safest and most effective use of this
instrument, it is important that the user fully understand the product.
Please read and understand this entire manual and know the principles
and practices of safe diving before using this device. If you are using the
EMC-14 with the Nitrox functions enabled, the diver specifically
acknowledges that he has been adequately and thoroughly trained and
certified to engage in Nitrox diving by a professional, competent,
recognized training agency.
This Manual is divided into the following Sections:
Section Page
Operation 1
Clock Operation 4
Touch Programming 5
Warnings 7
Oxygen & PO2 factors 7
Configurable Items 9
Specifications and Maintenance 10
Liability, and Warranty 11
Itemized Index and Subjects 13
TOUCH CONTACTS:
The Contacts are used to let the user command the unit to do a number
of functions, communicate with a PC for extracting information or
configuring the unit, and determining water conductivity. When Contacts
1 & 2 are shorted, the EMC-14 can detect the difference between wet
fingers, metal objects, fresh water, salt water, and a PC interface probe.
TURNING ON THE EMC-14:Although the EMC-14 automatically turns
on when it is submerged in water, it is STRONGLY recommended that
the unit be manually powered up by simultaneously touching Contacts 1
and 2 for two seconds with two wetted fingers. This allows the diver to
ensure that the unit is operating correctly and has adequate battery
capacity prior to entry. Once activated, the unit will remain on for 60
minutes. If a dive is not initiated within these 60 minutes, the EMC-14
automatically shuts off. Every time Contacts 1 & 2 are bridged with wet
fingers, the unit will stay on for one full hour.
The EMC-14 will not turn on if the altitude is greater than 4,875 meters or
if the battery voltage is less than 1.6 volts, or a fault is detected during the
self-test.
As the EMC-14 first recognizes a turn-on command, it begins a
“Diagnostic” function where many aspects of the system will be exercised
and tested. This procedure takes about five seconds. During this time,
all of the segments in the display are turned on so that the user can
confirm their operability. Should a test indicate a malfunction or marginal
test, the unit will turn back off again. The user should ensure that all of
the display segments are on and operating correctly.
TURNING OFF THE EMC-14:After the Post Dive Interval following a
dive, the EMC-14 will remain on for one hour before automatically
entering its "Sleep Mode". During the Sleep Mode, all calculations
continue but the display is off. This is a power saving feature of the
EMC-14. The unit will continue calculating Surface Interval, compartment
off gassing as required, and any changes in altitude as it affects Nitrogen
Loading. The current Surface Interval and PreDive Predictions can be
viewed by reactivating the unit
MAIN EMC-14 OPERATING MODES:
Surface Interval (No Nitrogen Residual)
Surface Interval (With Nitrogen Residual)
Dive Mode (Normal No Deco)
Decompression Mode
Post Dive Interval
Touch Programming
SURFACE INTERVAL:
After completion of the Self-Diagnostic mode or after the Post Dive
Interval following a dive, the EMC-14 enters the Surface Interval. This
period has two screens, a Primary and an Alternate. The Primary and
Alternate screen alternate ever four seconds, this cycle time is settable
via Analyst®. The Primary Screen displays, if applicable; current Surface
Time, the previous dive‟s Maximum Depth, the previous dive‟s Bottom
Time, Dive of Day number, current Time to Fly, Altitude and Temperature.
The Alternate Screen displays current calculated CNS, time of day
(alternates with current calculated OTU), and current battery voltage.
Figure 2 shows the display with no residual Nitrogen (a clean Dive).
Figure 4 shows the display with residual Nitrogen (a repetitive dive).
Figure 5 shows the alternate screen without residual Nitrogen, figure 6
with.

2
“Surface Time” starts at zero after a dive and begins counting minutes. If
the computer shuts off (enters the sleep mode) and is turned on with
Nitrogen residual left, the Surface Time continues to count. If the
computer shuts off (enters the sleep mode) and is turned on with no
Nitrogen residual, the Surface Time will be zero.
“Dive of Day” starts at zero and increments after each dive regardless of
the calendar day. When there is no remaining Nitrogen residual, the Dive
of Day is set to zero and the computer is referred to as a „clean‟ system.
“Time to Fly” is displayed as the number of hours remaining until the
nitrogen residual reaches zero plus a twelve-hour safety factor. Flying is
not recommended until Time to Fly reaches zero.
“Barometric Altitude” is indicated in six ranges via the Ascent Rate Bar
Graph as follows (Altitude compensation is seamless up to 4,875 meters
above sea level). The six ranges are for display purposes only: The
EMC-14 actually senses and computes extremely small altitude changes
and hence, is called “Seamless”. The term “Barometric Altitude” is used
instead of just “Altitude” because the EMC-14 measures Barometric
Pressure to determine Altitude. Barometric Altitude can vary from actual
Altitude by over +/- 305 meters! Barometric Altitude is what important to
the body when diving.
DIVE MODE:
Whether in the Surface Interval, PreDive Prediction Mode, Programming
Mode or the Logbook Mode, the EMC-14 will automatically enter the Dive
Mode whenever the unit determines that it is in water deeper than 1.5
meters.
On the Primary Screen the Surface time will be replaced with the current
Bottom Time. Maximum Depth will be replaced with current Depth,
displayed in one tenth meter increments. Bottom Time will begin once
the EMC-14 senses that the diver has descended below 1.5 meters and
continues until the diver has ascended above one meter. The maximum
Bottom Time displayed is 19 hours 59 minutes.
The Alternate Screen will display the current FO2value that the unit is
using in its NDC calculations, the current CNS and OTU values, the
current battery voltage and the Max Depth (so far this dive). (Figure 7)
A Depth Alarm, which can be set to warn the diver should a certain depth
be exceeded, is set at 39 meters from the factory. When the Depth
Alarm is issued the “WARNING” legend and Depth Digits will flash on and
off once per second. The depth alarm is disabled if in the
Decompression Mode since flashing depth digits have another meaning
in this Mode.
The maximum depth achieved on the current dive is shown as “MAX
DEPTH”. This is updated once per second.

3
“REMAIN TIME” (NDC) is the remaining time (in hours and minutes) that
the diver can stay at the current depth without requiring decompression.
A “Two Minute Warning” will be issued when this time reaches two
minutes or less. The “WARNING” legend and “REMAIN TIME” digits will
flash. By immediately ascending to a shallower depth, the diver may
avoid a required decompression stop.
Temperature is measured for two purposes. One is to compensate the
Depth Transducer for Temperature variations. The other is to
compensate the Nitrogen algorithm for changes in Temperature that may
affect the body. Both of these purposes require that the Temperature be
very slow reacting, just like the Depth Transducer and the body. This
slow-reacting Temperature is what is displayed. For Temperature effects
on the body, the amount of compensation can be set from NORMAL to
REDUCED with the Analyst® PC software Interface (see Analyst®
Section), if the diver is using a good dry-suit in cold water. Temperature
compensation starts at 75 degrees F and gets progressively more
conservative as the temperature decreases. There is no compensation
above 75 degrees F.
Bottom Time will begin once the EMC-14 senses that the diver has
descended below 1.5 meters (see Training Mode) and continues until the
diver has ascended above one meter. The maximum Bottom Time
displayed is 9 hours 59 minutes.
ASCENT RATE BAR GRAPH:
The Ascent Rate bar graph and alarms are active in both the Dive Mode
and Decompression Mode. The five-segment bar graph is used to
display the diver's rate of ascent.
Via the Analyst®PC Interface, the Ascent Rate Alarms and Bar Graph
can be set to the users preferences.
The first option is a VARIABLE-BY-DEPTH Ascent Rate. When on, the
Ascent Rate Alarm is determined by depth. As the diver ascends to
shallow depths, the Maximum Ascent Rate is lowered. The Maximum
Ascent Rates and their associated depth are:
18 meters or deeper 18 meters per minute
18 to 9 meters meters per minute equal to the depth
Less than 9 meters 9 meters per minute
If VARIABLE-BY-DEPTH is off, the Maximum Ascent Rate Alarm and Bar
Graph is specified by the user and can be from 6 to 18 mpm, in one-
meter increments.
Another selection is the bar graph itself. The two selections are either
FIXED or PROPORTIONAL.
With FIXED, each of the five bars indicates an additional 3 meters per
minute of Ascent Rate regardless of the Maximum Ascent Rate selected.
With PROPORTIONAL, each of the five bars indicates 20% (one-fifth) of
the selected Maximum Ascent Rate.
For FIXED, the maximum ascent rate is 18 meters per minute. With this
setting, no bars will illuminate if a diver is ascending at a rate less than 3
meters per minute.
If the diver has an Ascent Rate that exceeds the selected maximum, the
entire Ascent Rate Bar Graph will flash once per second, and the
WARNING legend will illuminate.
The sensitivity or responsiveness of the Ascent Rate may be selected via
the Analyst®, eight different levels of sensitivity are available.
NOTE: Customizing the Ascent Rate and Ascent Rate Bar Graph are
among many of the additional programmable features available when
using the Analyst®PC Interface. Available features are described in the
section “USER CONFIGURABLE OPTIONS”.
As shipped from the factory, the Ascent Rate is set for VARIABLE-BY-
DEPTH AND PROPORTIONAL.
DECOMPRESSION MODE:
Should a no-decompression limit be overstayed, the EMC-14 will enter
the Decompression Mode. In this mode, the Ceiling digits will display the
depth at which the diver must stop and not ascend above during final
ascent. The “TEMP” legend and two digits will be replaced with the
“CEIL” legend and two digits. The Ceiling will start at 3 meters and
increase in three-meter increments as the diver remains at a relatively
deep depth.
The Remaining No-decompression Time and “NDC” legend will be
replaced with Decompression Time and “DEC” legend (Figure 16d). Both
STOP time and TOTAL time are displayed in the lower three digits of the
screen in hours and minutes. STOP and TOTAL time will alternate at the
rate of once every two seconds. In this way, the diver can view the time
to spend at a particular STOP depth, and the TOTAL time it will take to
complete all STOPS. Clearly, the larger of the two alternating numbers is
the Total Decompression Time of all stops, and the smaller of the two
numbers is the time required at the current stop. At the ten-foot stop, the
TOTAL and STOP times may be the same and therefore appear to not
alternate.
When at a specific stop, the required decompression time at that stop is
as shown, and will appear to count down as it is recomputed every
second, based on the divers exact current depth. The Decompression
times (both Stop and Total) are accurate only if the divers‟ depth is
exactly the same as the required Ceiling. However, it is not necessary to
be precisely at that specified Ceiling. Appropriate In-gassing or Out-
gassing will be computed regardless of the divers‟ current depth.

4
A small margin shallower than the Ceiling also exists. Should a Ceiling
be „violated‟ (diver is shallower than Ceiling), the “WARNING” legend will
illuminate and flash along with the Depth and Ceiling digits. This warning
will continue until the Depth has been corrected. Out-gassing will
continue even though the diver is shallower than the Ceiling. There is no
„Gauge‟ mode or „Lockout‟ on the EMC-14.
If the diver surfaces before satisfying his decompression obligation, the
EMC-14 will continue to give out-gassing credit as if it were in a dive, but
at a depth of zero meters and will satisfy the decompression time
requirements of the required stops using an FO2of 21%. The unit will
continue to log data and perform as if actually in a dive. When the
decompression obligation is finally satisfied, the ten-minute “PostDive
Interval” will begin.
NOTE: COCHRAN does not intend for this instrument to be used for
deliberate Decompression diving.
POST DIVE INTERVAL:
During the first ten minutes (or up to thirty minutes if the unit is in the
Training Mode) after a dive, the EMC-14 is in the Post Dive Interval. The
flashing "SURF" legend and a Surface Time of less than ten minutes (or
up to thirty if the unit is in the Training Mode) indicate this. Should
another dive be commenced before the completion of the Post Dive
Interval, that dive will be considered an extension of the previous dive. In
this case, Bottom Time will NOT include the time spent on the surface in
this Post Dive Interval. However, when reviewing the profile with the
Analyst®, the time spent on the surface in this period will be shown.
CONFINED WATER PROTOCOL (Training Mode): The EMC-14 is one
of the first dive computers to offer an operating mode designed to record
and store data from training dives. That is, dives performed in shallow
water environments (swimming pools, shallow lakes, lagoons, etc.) or
calm open water environments that have less than 1-foot seas. In the
Training Mode, the EMC-14 enters the Dive Mode at a depth of .6 meters
instead of 1.5 meter and will exit the Dive Mode at .3 meters instead of 1
meter. Also the Post Dive Surface Interval may be extended, via the
Analyst®from10 minutes up to a maximum of 30 minutes in 1-minute
increments after which the dive data is stored in the computer's memory.
These changes permit the Instructor to record the complete training
session, including in-water surface periods, as a single dive. The
Training Mode can only be enabled/disabled via the Professional
Edition of the Analyst®PC Interface.
CLOCK MODE: The Clock operating mode of the EMC-14 is NOT
enabled when shipped from the factory. It can be enabled via the
Analyst® P.C. Interface or at an Authorized Cochran Dealer.
TOUCH PROGRAMMING MODE: Can only be accessed when the unit is
in the Surface Interval and allows the user to view or program into the
dive computer:
Setting Date Clock Time
The PreDive Prediction Mode
Displaying Mode, mode value, CNS, OTU & battery voltage
A Maximum Depth Alarm
An Added degree of Conservatism from 0 to 50%
Setting oxygen percentage of blend 1 in the Constant FO2Mode
Access the Logbook Mode
While all EMC-14 configurations share certain programming features
others are dependent upon the specific configuration of the unit.
Refer to the appropriate manual section for the relevant
programming menu items.
TOUCH PROGRAMMING - CLOCK: When the EMC-14 is placed into
the Clock mode it will display the time of day in an am/pm day format.
The clock will continue to run when the EMC-14 is in the Dive Computer
Mode. The EMC-14 can be placed into the Clock Mode from the Dive
Computer Mode when the unit is in the Normal Surface Interval, while the
unit is in Clock Mode the Dive Computer will be in the “Sleep” mode.
NOTE: This Time of Day clock is the same clock that is used to time
stamp dives. Modifying the Time of Day clock and/or the Date will
affect the Local Time/Date as viewed via the Analyst®.
CLOCK PROGRAMMING PROCEDURE:
To begin the programming sequence:
1. Turn the unit on;
2. Using a coin or other conductive metal object, briefly bridge
Contacts 1 and 2 until the CLoCk Menu is seen on the display (fig
30).
3. To enter the Clock submenu, bridge Contacts 1 & 2 with wetted
fingers. This will cause the unit to display the CLoCk dAte selection
(fig 31).
4. Using a coin or other conductive metal object, bridge Contacts 1 & 2
to access the month of the CLoCk Date setting screen fig 32.
5. Bridge Contacts 1 & 2 with wetted fingers. This will cause the
months tens digit to flash.
6. Shorting Contacts 2 & 3 with a coin will increment the numeric value;
continue until the required value is displayed.
7. Next using wetted finger, bridge Contacts 1 & 2 to select the next
digit; once selected the digit will flash to identify that it is being
programmed. Bridge Contacts 2 & 3 till the desired value is
displayed.
8. To select the Day short Contacts 1 & 2 with a coin, increment as in
step 6 and 7 (fig 34).
9. Repeat step 5 through 7 until all digits have been programmed.
10. To select the Year short Contacts 1 & 2 with a coin, increment as in
step 6 and 7 (fig 33).
11. Repeat step 5 through 7 until all digits have been programmed.
12. To set the Time short Contacts 1 & 2 with a coin, increment as in
step 6 and 7 (fig 40).
13. Repeat step 5 through 7 until all digits have been programmed.
14. To save the changes that have been made an d to enter the Clock
Display Mode, bridge Contact 1 & 2 with a coin or other conductive
metal object. Once the next programming option is displayed the
changes have been saved.

5
To exit the Clock Mode Bridge contacts 1 & 2 with wetted fingers and the
computer will return to the Dive Computer Mode‟s Surface Display.
NOTE: Ensure that the EMC-14 is in the Dive Computer Mode before
commencing a dive.
Figures 30, 31, 32, 33, 34 and 41 show how the Clock display screens
appear.
Figure 40 shows how the Clock display screens appear.
NOTE: Once the EMC-14 is placed in Clock Mode the unit will remain
in that mode until exited by the diver.
TOUCH PROGRAMMING MODE:
NOTE: To enable the Programming Mode, the EMC-14 must be on
the Surface and not in the Post Dive Interval.
NOTE: All visual alarms are suspended while the EMC-14 is in the
Programming Mode. Upon exiting the Programming Mode all
alarms are reactivated.
NOTE: Once a value has been changed and the next menu option
selected, the new value is stored.
NOTE: It is strongly recommended that the Programming Mode is
activated again and what was stored is reviewed.
NOTE: If the EMC-14 is left in the Programming mode for five
minutes without the contacts being touched, the unit will
automatically exit the Programming Mode and return to the
Surface Interval. Once this occurs the EMC-14 will retain the
modified programmed settings but options that have not
been modified will retain their current settings.
TOUCH PROGRAMMING MODE - PROCEDURE:
Contacts 1, 2, & 3 are for programming sequences.
To begin the programming sequence:
1. Analyze the gas blend using a calibrated Oxygen Analyzer.
2. Turn the unit on.
3. Using a coin or other conductive metal object, briefly bridge Contacts
1 and 2 until the Programming Menu is seen on the display. The
Programming Menu options depend on whether the unit is activated
for Clock, and /or Nitrox. The Menu options are displayed in
sequence, incrementing to the next selection each time that Contacts
1 & 2 are bridged with a coin. The program option is displayed on
the upper row of the display. The current setting for this option is
displayed in the lower right of the display.
4. To reprogram the displayed menu values, bridge Contacts 1 & 2 with
wetted fingers. This will cause the current setting to flash or in the
case of multi-digit numbers, the least significant digit will flash. The
clock will toggle between on and off.
5. Using a coin or other conductive metal object, bridge Contacts 2 & 3
to increment the numeric value. Next using wetted finger, bridge
Contacts 1 & 2 to select the next digit, once selected the digit will
flash to identify that it is being programmed. Bridge Contacts 2 & 3 till
the desired value is shown.
6. Repeat step 5 until all digits have been programmed.
7. To save the changes that have been made bridge Contact 1 & 2 with
a coin or other conductive metal object. Once the next programming
option is displayed the changes have been saved.
All programming sequences use the same routine of using Contacts 1
and 2 to SELECT the next programming sequence and Contacts 2 and 3
to INCREMENT the specified value.
PROGRAMMING MENU - Air Only:
The following table lists the various programming choices with their
display identification and figure number.
Identification Description Figure Page
CLC Clock –if enabled 30 5
PdP PreDive Prediction 12 8
InF Misc. Information 14 8
dEP AL Depth Alarm, Max value
is 55 or 99 meters 16 8
(Depending upon unit configuration)
Con Added Conservatism, Max
value is 50%. 18 8
LOG Logbook 24 8
PROGRAMMING MENU - SINGLE GAS NITROX
The following table lists the various programming choices with their
display identification and figure number.
Identification Description Figure Page
CLC Clock –if enabled 30 5
PdP PreDive Prediction 12 8
InF Misc. Information 14 8
dEP AL Depth Alarm, Max value
is 55 or 99 meters. 16 8
(Depending upon unit configuration)
Con Added Conservatism, Max
allowed value is 50%. 18 8
EAn 1 Oxygen percentage of Blend,
Allowed value 21 to 50 20 8
LOG Logbook 24 8
TOUCH PROGRAMMING - PREDIVE PREDICTION:
PreDive Prediction is accessed via the Touch Contact Programming
Menu. This enables the diver to view the PreDive Prediction information
at the touch of the Contacts. The EMC-14 PreDive Prediction starts at 9
meters and increases in 3 meter increments. PreDive Predictions will
terminate when the No-Decompression (NDC) time prediction reaches
two minutes or a maximum depth of 99 meters is reached. Additional
Conservatism, Residual Nitrogen, blend #1 oxygen percentage and
Barometric Altitude can affect PreDive Predictions. Once the maximum
PreDive Prediction depth has been reached the unit will return to the
Surface Interval.
During the PreDive Prediction Mode, the unit will compute and display the
maximum safe time and the calculated PO2value at that depth.

6
TOUCH PROGRAMMING - INFORMATION DISPLAY:
The InFormation display is accessed via the Programming Mode. The
information presented will depend on the configuration of the dive
computer. The information in the lower middle of the screen indicates
whether unit is in the Constant FO2 (Nitrox) or Air Mode. The following
table lists the identification and the description.
Identifier Description
F0 Air only
F1 Single Blend Nitrox, 21 to 50%
Battery voltage is displayed in the middle right center of the screen as a
two-digit number with an implied decimal point. If the unit is configured
for Constant FO2 (Nitrox), the screen will display the current CNS, along
with the Time of Day and battery voltage. The current CNS exposure
level is displayed on the middle left as a two-digit number proceeded by a
lower case “c”. The current time is displayed in the middle center. The
CNS value is expressed as percentages. Figure 24a displays a typical
InFormation screen for a unit that is enabled for Nitrox.
TOUCH PROGRAMMING - DEPTH ALARM: The Depth Alarm allows
the diver to select a maximum depth below which the diver does not wish
to descend before an alarm is issued. This depth can be set from 0 to 55
or 99 meters in one-meter increments (depending upon unit
configuration).
TOUCH PROGRAMMING - CONSERVATISM: This programming
function allows the diver to input an added degree of Conservatism into
the EMC-14 algorithm. Via Touch Programming the Conservatism can
be set from 0 to 50%.
TOUCH PROGRAMMING - BLEND #1:
The oxygen percentage of Blend #1 can be programmed from 21.0% to
50.0%. Once programmed the oxygen percentage will remain at the
value programmed until changed by the user.
TOUCH PROGRAMMING - LOGBOOK MODE: The Logbook of the
EMC-14 has two screens, a Primary Screen and an Alternate Screen.
The Logbook is accessed via the Touch Contact Programming (see page
15). This enables the diver to view dive statistics; the EMC-14 has the
ability to provide diving data for the most recent 256 dives. The most
recent dive will be displayed first. To view the next dive, touch the
contacts 1 & 2 with wetted finger after pausing for a few seconds. Do not
use a metal object such as a coin or knife-blade once in the Logbook
since it will cause the unit to exit the Logbook and return to the Surface
Interval.
Information contained in the Logbook include:
Overall Dive Number Minimum NDC Time
Fastest Rate of Ascent Minimum Water Temperature
Bottom Time Surface Interval Before Dive
Maximum Depth Ending Battery Voltage
Maximum DEC Time (Deco Dive) Maximum Ceiling (Deco Dive)
The Dive Number that is displayed on the Logbook Menu screen (Figure
25) permits the diver to identify the number of dives made with that EMC-
14. If the example shown is the most recent dive made, it can be
identified that 136 dives have been made with this unit.
Figure 26 shows that dive 136 started at 10:18 AM on the 8th of October
2003.

7
Figures 27 & 28 display the Logbook of a Normal Dive.
While Figures 29 & 29A display that of a Deco Dive
WARNING INDICATIONS: Failure to observe visual warnings and take
corrective action may result in injury or death. In general, if the
WARNING legend is flashing, some other digits should be flashing to
indicate the anomaly.
If the diver is ascending faster than the selected maximum ascent
rate, then the top bar of the ascent bar graph will flash and the
“WARNING” legend will illuminate.
If the diver descends below the user set Depth Alarm, the Depth
digits will flash. The Depth alarm is not active in the
Decompression Mode to avoid confusion with the “Shallower Than
Ceiling” alarm.
If the battery voltage goes below 2.4 volts, the “BATT” legend will
begin to flash on and off once per second.
If the diver has less than two minutes of No-Decompression Time
(NDC) remaining, the “WARNING” legend will illuminate and flash
along with the Remaining NDC time digits.
During a Decompression dive, if the Depth is less than the CEILING,
the “WARNING” legend will illuminate and flash along with the Depth
and Ceiling digits.
If the dive computer determines that either the Depth or
Temperature sensor is malfunctioning. The “WARNING” and
"SENSOR" legends will illuminate, The Screen will also display
either "DEPTH" and/or "TEMP".
For High PO2, see “OXYGEN TOXICITY FACTORS” on page 7.
For High CNS, see “OXYGEN TOXICITY FACTORS” on page 7.
SENSOR WARNING: The EMC-14 has the capability of monitoring the
integrity of it‟s' sensors, both the low-pressure (depth/altitude) and the
temperature. When the computer detects an error in one of the
transducers, the diver is alerted to this condition by the illumination of the
“WARNING” and "SENSOR" legends The "DEPTH" Legend will
illuminate to indicate the low-pressure transducer or the "TEMP" legend
for the temperature transducer (see figure 18a). The “WARNING”
legend, along with either the Temperature digits or the Depth digits and
the Legend will flash once per second. In the highly unlikely situation
were both sensors are detected as having errors, both the "DEPTH" and
"TEMP" legends will illuminate. This warning will be issued whether the
computer is in the Surface Interval, Dive Mode, Decompression Mode or
Post Dive Interval. In the unlikely case that your computer issues one of
these warnings the unit should be returned to the factory for evaluation
and/or repair.
Figure 39 shows a Sensor Warning, in this case a Depth Sensor, as it
would be displayed in the Dive Mode. If the Sensor Warning was for the
temperature sensor it would display "TEMP“.
OXYGEN TOXICITY FACTORS: The EMC-14 has the ability to track
Oxygen Toxicity levels for the Central Nervous System (CNS) as well as
the Mission Oxygen Tolerance Units Dose (OTU). In addition, a
maximum Partial Pressure of Oxygen (PO2) warning alarm can also be
set.
As long as one or more of these three parameters is outside its limits, the
“WARNING” legend on the display will continue to flash.
These three functions are not active if the NITROX capability is disabled
via the Analyst®PC Interface.
PARTIAL PRESSURE OF OXYGEN (PO2): High levels of PO2can
cause severe Oxygen poisoning. Widely different levels of PO2 can
affect individual divers. The user via the Analyst®can set the PO2alarm
to any level between 0.50 ATA and 1.59 ATA. As shipped from the
factory, this is set to 1.40 ATA. Should the PO2be above the alarm set
point, the “WARNING” legend will illuminate and the displayed PO2value
will flash.

8
CENTRAL NERVOUS SYSTEM (CNS) TOXICITY: By the accepted
definition of CNS toxicity, should a PO2value of greater than 1.6 ATA be
measured; the CNS Toxicity will be 100%. During the Surface Interval,
this percentage will decrease as the CNS declines toward zero.
Whatever the current CNS Toxicity level, it can also be viewed on the
Surface Interval Alternate Screen or on the InFormation screen in the
Programming Mode.
The user via the Analyst®can set the CNS Toxicity alarm to any level
between 40% and 80% of the maximum allowable limit. As shipped from
the factory, this is set to 50%. Should the CNS Toxicity reach 50% of the
maximum allowable, the “WARNING” legend will illuminate and on the
Alternate Screen the displayed CNS percentage will be flashing along
with the “WARNING” legend.
OXYGEN TOLERANCE UNITS (OTU): An issue with long term
breathing of higher partial pressures of Oxygen above 0.5 ATA is
Pulmonary Oxygen Toxicity or sometimes called WHOLE BODY which
must be tracked properly.
The EMC-14 will track OTU based on Dr. Bill Hamilton‟s „REPEX‟ method
of oxygen exposure management. The OTU Dose is an exponential
function of oxygen partial pressure and time. The time-dependent limit
varies with length of time (days) that the diver continues to dive without
full recovery to zero OTU. The Mission OTU Clock tracks the OTU, which
is a running clock that tracks long-term Oxygen exposure. This clock may
run for several weeks if frequent dives are made using high levels of PO2.
The recovery portion of the OTU algorithm is a linear reduction of OTU
over time. The Mission OTU clock is reset to 0:00 when the OTU Dose
reaches zero. Symptoms of Pulmonary Oxygen Toxicity include burning
in the throat and chest, coughing, and shortness of breath. Discontinue
diving and consult a Physician should any of these, or other, symptoms
appear.
The current Mission Clock, CNS, and OTU values can be seen via the
Analyst®PC interface or the current CNS and OTU values can be viewed
on the Alternate Screen while in the Surface Interval, Dive Mode,
Decompression Mode or Post Dive Interval. The current CNS and OTU
values can also be viewed via the Touch Contact Programming mode by
selecting the InFormation option. The user via the Analyst®can set the
OTU Toxicity alarm to any level between 40% and 80% of the maximum
allowable limit. As shipped from the factory, this is set to 50%. Should
the OTU Dose reach 50% of the maximum allowable, the “WARNING”
legend will illuminate and on the Alternate Screen the displayed OTU
value will be flashing along with the “WARNING” legend.
Figure 38 shows a CNS exposure over the alarm set point (50%), in the
situation were both the CNS and the OTU exposure was over their set
points both values would flash.
TOUCH CONTACT PROGRAMMING SCREENS: The following are all of
the screens that the EMC-14 is capable of presenting in the Touch
Programming Mode. Refer to the particular configuration for appropriate
screens.
DATA STORAGE TYPES & CAPACITY: The EMC-14 has the following
internal distinct data storage activities that can be recalled, viewed, and
stored with the Analyst®PC computer interface:
Current Variable Information: Local Time, CNS toxicity, OTU
Toxicity, Altitude, Battery voltage, Current unit Temperature, 14
tissues loading, and Time to Fly.
Current Configuration Data: As can be seen in “USER
CONFIGURABLE ITEMS”, below.
Historical Totals Summaries: Dive Time, Number of Dives,
Number of Marginal Dives, Number of Violated Dives, Number of
Warnings, Decompression Dives, Decompression Time, Maximum
Depth and Ceiling, Maximum Depth and Ceiling Dive Number.
Each Dive Beginning Statistics: 14 tissues loading, Local Time
Clock, Dive of Day, Dive Number, Surface Time, CNS Toxicity, OTU
Dose, OTU Mission Clock, Altitude, Time to Fly, Battery Voltage.
Capacity is the most recent 256 dives.
Each Dive Ending Statistics: 14 tissues loading, Bottom Time,
Max Depth, Average Depth, Min NDC Time, Max Deco Time, Max
Deco Ceiling, Missed Ceiling, Missed Deco Time, CNS Toxicity,
OTU Dose, OTU Mission Clock, Max PO2, Max Ascent Rate, Max
A/R Time, Max A/R Depth, Min Temperature, Average Temperature,
Maximum Temperature, Min Battery Voltage, Time to Fly, number of
Warnings. Capacity is the most recent 256 dives.
Each Dive Configuration Data: Full and complete configuration of
the system, including Blend #1 Oxygen %, User Conservatism.
Capacity is the most recent 256 dives.
Profile Graphical Information: Depth Graph, Ascent Rate Graph,
Temperature Graph, PO2Graph, O2% Graph, CNS Graph and OTU
Graph. Capacity is 180 hours at one second sampling (dependent
upon memory configuration).
Inter-Dive Events: Number of Initializations, Unit Activation,
Altitude Changes of 150 Meters, Temperature Changes of 5.5
degrees C, Low Batteries, Sensor Malfunction, Analyst®interface
with Dive Computer.