Tusa iq-650 element computer manual 12-2917-r02

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Time Displays

Time displays are shown in hour:minute format (i.e., 1:16

represents 1 hour and 16 minutes, not 116 minutes).  The colon

that separates hours and minutes blinks once per second when

the display is indicating real time (e.g., Elapsed Dive Time), and

is solid (not blinking) when times are calculated projections (e.g.,

Time to Fly).

The Main Time display is located at the top of the display (Fig.

5a) and a second time display (Fig. 5b) is located in the

center/right.  Both displays are identified by a clock icon.

•  Time of Day (Fig. 6a) can be set for 12 hour format (Am/Pm)

or 24 hour format.

Temperature Display

Ambient Temperature is displayed in the center/left portion

of the screen (Fig. 6b) while in the Surface Mode and Log

Mode, and can be viewed as part of an Alternate Display when

the button is pressed while in a dive mode.

NOTE:  The informational displays are described in

detail as the various operating modes they appear in

are presented throughout this manual.

Fig. 5 - TIME

Fig. 6 - TEMPERATURE

a

b

b

a

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13

POWER SUPPLY

The Element utilizes one (1) type CR 2450 Lithium 3 volt cell style

Battery that should provide 300 hours of continuous, or 50

activation periods, of operation.

•  If you conduct 1 dive each time the unit is activated, you

should obtain approximately 50 dives.

•  If you conduct 3 dives each time the unit is activated, you

should obtain approximately 150 dives.

Battery  Indicator

A Battery Indicator (icon) provides an indication of Low Battery

condition.  When power is sufficient for normal unit operation,

the icon will not be displayed upon activation or during Surface

Mode (Fig. 7).  The icon is not displayed during any Dive

Mode(s).

Low Battery Condition

Voltage level is checked upon activation and every (1) minute

during operation on the surface.

•  When voltage decreases to < 2.75 v and is > 2.50 v, the

Battery icon will be displayed solid (Fig. 8a) as a warning

that the Battery is to be replaced prior to conducting any

further dives.

Fig. 8 - LOW BATTERY

Fig. 7 - ACTIVATION

(no Battery icon = normal)

a

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•  Upon decreasing to a voltage level that will no longer sustain

proper operation (<= 2.50 v), the icon will flash 5 times

followed by shutdown of the unit.

•  If a Low Battery Condition exists when the unit is activated

(by pressing the button), the graphic bAT and the Battery

Indicator will appear flashing for 5 seconds followed by

shutdown of the unit.

•  If the button is not pressed to activate the unit prior to a dive,

and a Low Battery Condition exists, the Battery Indicator will

appear flashing as a warning upon descent to 5 FT (1.5 M).

No other information will be displayed.

•  If the unit did not display a Low Battery Condition 'prior to'

entering the Dive Mode, and a Low Battery Condition occurs

during the dive, there will be sufficient battery power to

maintain unit operation for the remainder of 'that dive'.  The

Battery icon will then appear after the dive upon entry into

Surface Mode.

R

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P

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N SIBLE

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15

FO2 MODE

After Activation, the Element will operate as an AIR computer

without displaying information associated with oxygen calcula-

tions, unless it is set for Nitrox which is a percentage of O2

(FO2) other than AIR (a numerical value between 21 and 50 %).

When set for an FO2 value of AIR (Fig. 9), the Element will

perform calculations the same as if FO2 were set for 21% O2,

internally accounting for O2 accumulation for any subsequent

Nitrox dives.  However, O2 related displays, warnings, and the

O2BG will not appear on the display for that dive, or subse-

quent dives, unless FO2 is set for Nitrox (a numerical value of

21 to 50 %).

Once a dive is made with the unit set as a Nitrox computer (FO2

set for a numerical value), it cannot be programmed to operate

as an AIR computer until 24 hours after the last dive.  AIR will

not be displayed as an option in the FO2 Mode.  However, you

can set FO2 for 21% for use with AIR.

When FO2 is set at a value of 21% (Fig. 10), the unit will

remain set at 21% for subsequent Nitrox dives until FO2 is set to

a higher value, or until it automatically turns Off 24 hours after

the last dive and is reactivated.

Setting FO2 is described on Page 21.

Fig. 9 - FO2 Set for AIR

Fig. 10 - FO2 Set for 21%

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Fig. 11 - FO2 DEFAULT ON

Fig. 12 - FO2 DEFAULT OFF

FO2 50% DEFAULT

If the FO2 Default is set to ON (Fig. 11) and FO2 is set to a

value greater than 21%, the FO2 set point value will automati-

cally revert to 50% 10 minutes after that dive.  The Maximum

Depth that can be achieved with a PO2 of 1.60 ATA will also

be displayed.

•  FO2 must therefore be reset for each repetitive nitrox dive,

or the value will automatically Default to 50(%) and the dives

will be calculated based on 50% O2 (50% nitrogen) for

oxygen calculations and 21% O2 (79% nitrogen) for nitro-

gen calculations.

If the Default is set to OFF (Fig. 12), the FO2 value for repetitive

dives remains the same as previously set until the Set Point is

manually changed.

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