NiTek Duo Dive Computer User Guide Date of purchase: www.diverite.
Content DEVELOPED BY Dive Rite 175 NW Washington Street Lake City, FL 32055 Phone: 386.752.1087 Fax: 386.755.0613 Web: www.DiveRite.com COPYRIGHT NOTICE Copyright © 2003-2004 Lamartek, Inc. dba Dive Rite WARRANTY INFORMATION Dive Rite will—at its sole discretion—repair or replace NiTek Duo components proved to be damaged by faulty manufacture or material, at no cost, for a period of up to one year (365 days) from the date of purchase. This manual is copyrighted by Lamartek, Inc. dba Dive Rite.
Content Table of contents Chapter 1 Introduction • 1 Overview • 2 Features and functions • 3 Specifications • 5 Warnings • 6 Chapter 2 Using the NiTek Duo • 9 Getting started • 10 Accessing display modes and screens • 11 Time display mode • 12 Dive option set and display mode • 14 Plan mode • 24 Dive computer mode • 26 Gauge mode • 34 Log mode • 36 Profile mode • 38 PC transfer mode • 40 Surface mode (upon surfacing from a dive) • 41 Altitude operation • 43 Chapter 3 Care and maintenance • 45 Proper h
Chapter 1 Introduction Summary This chapter provides an overview of the NiTek Duo, lists the NiTek Duo’s features and functions, and covers warning information that should be read before using your NiTek Duo.
Introduction Overview Congratulations on your purchase of the NiTek Duo dive computer. The NiTek Duo is a sophisticated and comprehensive dive computer that was designed to offer you the latest in dive computer technology, safety, and reliability.
Introduction Features and functions The NiTek Duo incorporates a number of important modes and features: • The NiTek Duo turns on automatically upon descent • On the surface, the NiTek Duo constantly displays a minimum of date and time • The NiTek Duo uses easily accessible and highly reliable push buttons instead of exposed electrical contacts • The NiTek Duo can be programmed to monitor exposure to two different gas mixtures during a dive.
Introduction atmospheres for mix1 and 1.6 atmospheres for mix2, and when cumulative exposure to elevated PO2s exceeds recommended limits.
Introduction Specifications Algorithm: Buhlmann ZH-L16 Sample tissues: 9 Tissue half-lives: from 5 to 640 minutes Size and weight Diameter: 2.5 in (62 mm) Height: 1.0 in (25 mm) Weight: 4 ounces (115 g) Display face Backlight illumination Low battery indicator Three user buttons Water immersion switch Depth sensor Sea or fresh water calibration Measuring range: 0 to 328 feet (0 to 100 m) measured every second (Gauge mode 656 feet (200 m) Accuracy: +/- 3% + 2 feet (0.
Introduction Warnings This information has been developed for your safety. Please read and understand this manual completely before using your NiTek Duo dive computer. Important safety information: • Before using your NiTek Duo, it is extremely important that you read the following points—as well as similar warning and caution notices that appear throughout this manual. Failure to do so could result in damage to or loss of equipment, serious personal injury, or death.
Introduction all previous dives in the same repetitive dive series and is thus, accurately monitoring the diver’s total exposure to oxygen and nitrogen. • Neither the NiTek Duo—nor any other dive computer— physically measures the amount of nitrogen present in body tissues or the rate at which nitrogen is being absorbed or released.
Introduction • Do not rely solely on this or any other dive computer. Take a back-up dive computer or dive tables (along with a separate means of monitoring depth and dive time). • Be aware that the NiTek Duo makes assumptions regarding residual nitrogen based on altitude settings. Avoid making abrupt changes in altitude following a dive, as doing so may be very dangerous.
Chapter 2 Using the NiTek Duo Summary This chapter provides topics about using, setting, and understanding each of the modes and options of the NiTek Duo.
Using the NiTek Duo Getting started The NiTek Duo has many modes and screens and a number of options that can be changed depending on your dive location and profile. The following is a checklist of general things that you should pay attention to before, during, and after a dive. Before a dive • Check that the proper time and date are set. If you traveled, your NiTek Duo may be set to your home time zone. • Check that the proper mixes are set for mix1 and mix2.
Using the NiTek Duo Accessing display modes and screens There are some display modes that the NiTek Duo enters and/or exits automatically. For example, by taking the NiTek Duo underwater, the dive mode automatically turns on. Upon surfacing, the NiTek Duo automatically enters the time mode. Accessing other modes or screens requires the use of the NiTek Duo’s buttons. Button operation The NiTek Duo has three buttons (select, mode, and set), which are used to access the different modes and screens.
Using the NiTek Duo Time display mode Time display mode is the NiTek Duo’s default mode. The computer returns to this mode automatically upon surfacing from a dive and from other modes when a period of time has passed without any buttons being pressed. 3 4 2 1 In time display mode, “time” (1) is displayed at the bottom of the screen, and the date (2) and time (3) with seconds (4) are displayed. Time can also be displayed in 24-hour (military) time.
Using the NiTek Duo For example, 1:00 PM would be 13:00. 4. Press Mode. The computer returns to the time display mode. Entering time display mode from another mode When you are using other modes, it is very easy to return to the time display mode. To enter time display mode from another mode: 1. Press and hold Mode for two seconds. —OR— 2. Press Mode until “time” is displayed. Activating the back light The NiTek Duo has a back light that illuminates the screen. To activate the back light: 1.
Using the NiTek Duo Dive option set and display mode Dive option set and display mode is where all “dive” option settings are displayed and set up. There are two screens needed to view and set up all dive options. Using computer mode Computer mode is when the NiTek Duo is operating in the normal computer mode. “Dive” is displayed on the screen and all computer mode functions operate normally.
Using the NiTek Duo • • • • • (4) Dive profile sampling rate (5) Salt or fresh water use (6, 7) Maximum depth alarm (8, 9) Maximum time alarm (10) Metric or Imperial units of measurement There are three “display only” option fields that change based on how the above settings are set. • (11) Nitrox indicator: “Nitrox” is displayed if mix1 is set for a FO2 of greater than 21 percent. If mix1 is set for 21 percent (air), nothing appears. If mix1 is in “default,” the Nitrox indicator flashes.
Using the NiTek Duo Note: If you only plan on using one mix on your dive, you only need to set mix1. To set mix1 and mix2 percentages: 1. Press Mode until “dive” is displayed and flashing on the screen. 2. Press Select to select the mix1 field. 3. Press and release Set to increase the percentage. Press and hold Set to advance the percentages rapidly. The percentage will stop at 32 percent and again at 50 percent. 4. Press Select to advance to mix2. 5.
Using the NiTek Duo To set the safety factor: 1. Press Mode until “dive” is displayed and flashing on the screen. 2. Press Select until the safety factor field is flashing. 3. Press Set to select the desired safety factor. 4. When finished, press Select to advance to the next option (profile sampling rate) or to exit, press and hold Mode for 1 to 2 seconds to return to time mode. Setting the dive profile sampling rate The NiTek Duo allows you to choose how frequently it samples and stores depth data.
Using the NiTek Duo Setting for fresh or salt water use The NiTek Duo is capable of operating using fresh or salt water calculations. This is based on: • • One atmosphere of saltwater is 33 feet (10 meters) One atmosphere of freshwater is 34 feet (10.3 meters) Before going diving, set the computer to the type of water you are diving in. This allows for the most accurate calculations with respect to no-decompression limits, etc. To set for fresh or salt water: 1.
Using the NiTek Duo 5. Press Set to toggle the alarm on and off. 6. When finished, press Select to advance to the next option (dive time alarm) or to exit, press and hold Mode for 1 to 2 seconds to return to time mode. Setting the dive time alarm The NiTek Duo has a dive time alarm that is activated when the diver reaches the dive time that is set for the dive. When the dive time is reached, an audible alarm sounds and the screen flashes for three seconds.
Using the NiTek Duo To set for metric or Imperial operation: 1. Press Mode until “dive” is displayed and flashing on the screen. 2. Press and hold Select and Set simultaneously for 5 to 6 seconds. The computer beeps and changes to either feet (ft) or meters (m). 3. When finished, press and hold Mode for 1 to 2 seconds to return to time mode. Understanding FO2 default In your entry-level Enriched Air Nitrox training, you learned that among the greatest risks Nitrox (EANx) use poses is CNS oxygen toxicity.
Using the NiTek Duo Default warning indicated by Nitrox flashing and a dashed line for mix1 When and how FO2 default occurs One factor in determining if and when your NiTek Duo’s FO2 setting is in default, is whether you set one or both mixes for air or Nitrox. • If you set either mix for air (an FO2 of 21 percent), the computer assumes that subsequent dives will be made using air. This means that the mix set for air remains set for air, dive after dive, without defaulting.
Using the NiTek Duo computer’s ability to accurately monitor your exposure to oxygen no longer exists. Note: You should not rely on the NiTek Duo as the sole means of tracking your exposure to elevated partial pressures of oxygen (PO2s). It is recommended that you use either a second Nitroxcapable computer or another tracking method, such as Nitrox tables. Using gauge mode If you do not want to use the NiTek Duo as a normal “dive computer,” the NiTek Duo has a gauge operation.
Using the NiTek Duo 2. Press Set to select gauge operation. “Gage” is displayed in place of “dive.” 3. Press Select to set the profile sampling rate. Press Set to select 15-second or 30-second. 4. Press Select to set for salt or fresh water use. Press Set to toggle between “sea” and “fresh.” 5. Press Select to set the max depth alarm. Press Set to change the depth. The alarm turns on with “on” displayed above the depth. 6. Press Select to turn max depth alarm on or off. 7.
Using the NiTek Duo Plan mode Plan mode enables you to determine how long you can stay at various depths while remaining within the no-decompression limits. The no-decompression time limits are based on the percentage that is set for mix1. If you are making a dive within 24 hours of a previous dive, the no-decompression time limits are based on the residual nitrogen remaining. The two most important values that are displayed on the screen in plan mode are the depth and no-decompression time limit.
Using the NiTek Duo To enter plan mode: 1. Press Mode until “plan” is displayed on the screen. 2. Press Set to advance the depth or press Select to decrease the depth. The no-decompression time limits change automatically based on the depth. 3. If you want to exit plan mode, press and hold Mode for 1 to 2 seconds to return to time mode. WARNING: Do not plan dives to depths deeper than those for which the NiTek Duo is capable of displaying an available nodecompression limit.
Using the NiTek Duo Dive computer mode Dive computer mode is automatically entered when the computer enters the water. It begins performing its dive calculations once you descend below 5 feet (1.5 meters). Caution: Prior to diving, always check to ensure that the FO2 settings are correct and that the computer is not in FO2 default. While in diving mode, the computer calculates and displays information about your dive and prompts you with safety stop information and warnings if needed.
Using the NiTek Duo partial pressures of oxygen (PO2s). There are a maximum of eight bars. When all bars are displayed, it means that you have used 100 percent of your “CNS” clock. This graph increases when you descend due to higher partial pressures and may decrease when you ascend. (4) Depth: This is the current depth. (5) PO2: This is the partial pressure of O2 at your current depth. It is based on the FO2 settings for mix1 or mix2.
Using the NiTek Duo To display the secondary diving mode screen: 1. Press and hold Set. The back light turns on, and the secondary screen is displayed. 2. Release Set to return to the primary diving mode screen. Changing gas mixes underwater Because the NiTek Duo has the ability to use two different gas mixes (programmed in dive option set mode) during a dive, you need the ability to switch between mix1 and mix2 while underwater.
Using the NiTek Duo During this time, if you ascend above 10 feet (3 meters), the countdown pauses. It resumes when you descend below 10 feet (3 meters). If you descend below 20 feet (6 meters) during this time, “stop” and the three-minute countdown disappear; the NDL readings reappear. When you again ascend above 20 feet (6 meters), the three-minute countdown restarts. Warnings while in diving mode While in diving mode, there are several warnings that you should be alert to.
Using the NiTek Duo Ascent rate warning The NiTek Duo assumes that you keep your ascent rate within the following limits: Depth range Ascent rate 0 to 19 feet (0 to 5.9 meters) 26 feet (8 meters) per minute 20 to 59 feet (6 to 17.9 meters) 39 feet (12 meters) per minute 59 feet (18 meters) or deeper 52 feet (16 meters) per minute If you exceed these ascent rates, an audible alarm sounds for three seconds and “slow” is displayed and flashes on the screen.
Using the NiTek Duo Note: If the PO2 alarms activate at a depth of 20 feet (6 meters) or less, you most likely have not exceeded the limiting PO2. It is more likely that you forgot to set the FO2 percentages prior to the dive. As a result, the computer has entered the FO2 default. See “Understanding FO2 default” for more information.
Using the NiTek Duo OLI warning with “OLI” displayed and flashing on the screen Decompression warning If you exceed the no-decompression limits, the computer enters decompression mode. An audible alarm sounds for three seconds indicating that you have decompression stop requirements. Caution: Decompression diving is considered to substantially increase your risk of decompression illness more than dives made within no-decompression limits.
Using the NiTek Duo (3) Required stop time: This is the time you must remain at the indicated stop depth. (4) Total ascent time: This is the total amount of time (in minutes) you must spend at the decompression stops and the ascent time between decompression stops. (5) Nitrogen (N2) bar graph: This is how much nitrogen the computer assumes your body has absorbed. There are a maximum of nine bars.
Using the NiTek Duo Gauge mode Gauge mode is automatically entered when the computer enters the water. It begins displaying depth and time once you descend below 5 feet (1.5 meters). Gauge operation is when the NiTek Duo is operating simply as a depth gauge and bottom timer. “Gage” is displayed on the screen and exposure to nitrogen and oxygen and no-decompression limits are not tracked, and no bar graphs are displayed.
Using the NiTek Duo (2) Total dive time: This is the total time for the dive. (3) Temperature: This is the lowest temperature reached during the dive. (4) Max depth: This is the maximum depth reached during the dive. To toggle between screens underwater: 1. Press and hold Set. The back light turns on, and the computer switches to the secondary screen. 2. Release Set to return to the primary screen.
Using the NiTek Duo Log mode For each dive, the NiTek Duo stores information, such as depth, time, temperature, etc. in a log. This stored log information can be viewed directly from the NiTek Duo’s screen when in log mode. Because of the amount of information the NiTek Duo stores, there are two pages that you can toggle between for each dive. Each dive is assigned a number, beginning with one, for the day.
Using the NiTek Duo (4) Date: This is the month and day of the dive. (5) Ascent time: This is the time you surfaced from the dive, indicated by an up arrow. (6) Descent time: This is the time you started the dive, indicated by a down arrow. (7) Nitrogen (N2) exposure bar graph: This is the amount of residual nitrogen in your body at the end of the dive. (8) FO2 gas percentages: These are the FO2 gas percentages that you entered for the dive. All calculations were based on these percentages.
Using the NiTek Duo Profile mode Profile mode enables you to see a record of the depths you reached at various points during a dive. You can display a detailed profile of each dive stored in the log. When a dive is selected, the computer automatically displays the depth and the time in the dive when you reached that depth until it reaches the end of the dive. Dive profile information is either stored in 15- or 30-second intervals during a dive. This must be set in dive mode before a dive.
Using the NiTek Duo To view a dive profile: 1. Press Mode until “prof” is displayed on the screen. “Prof” is in only displayed for a second, and then switches to the dive log entry number for the “last” dive stored in the computer. 2. Press Set to scroll “up” through the logged dives. To fast scroll, press and hold Select. Press Select to scroll “down” through the logged dives. To fast scroll, press and hold Select. 3.
Using the NiTek Duo PC transfer mode You can transfer the stored dive log information to your personal computer using the optional NiTekLogic software and a USB interface. Note: This option is not currently available. To enter PC transfer mode: 1. Press Mode until “PC” is displayed on the screen. 2. Transfer the dive log data to your PC. 3. To exit PC transfer mode, press and hold Mode for 1 to 2 seconds to return to time mode.
Using the NiTek Duo Surface mode (upon surfacing from a dive) Once you surface from a dive, the NiTek Duo automatically switches to time mode, with “time” displayed on the screen. In addition to the normal information displayed in time mode such as time of day, there is other information that is displayed that pertains to the dive you just completed.
Using the NiTek Duo levels drop to a point where subsequent dives are treated as a single (non-repetitive) dives. This is not the same as “time to fly (see no-fly symbol below).” (3) O2 OLI bar graph: This indicates CNS toxicity level at the end of the dive. This drops as your surface interval time increases. (4) Nitrogen (N2) exposure bar graph: This is the amount of residual nitrogen in your body at the end of the dive. This drops as your surface interval time increases.
Using the NiTek Duo Altitude operation The NiTek Duo adjusts automatically for diving at altitudes of up to 19,685 feet (6,000 meters). To show that the NiTek Duo has made the altitude adjustment, it displays the altitude settings using symbols representing mountains.
Using the NiTek Duo • Do not use the NiTek Duo when the “E” symbol is displayed. This means that you are above an altitude of 19,685 feet (6,000 meters), which is beyond the NiTek Duo’s ability to function accurately. • Do not place the NiTek Duo in dive mode when making sudden, substantial changes in altitude, such as when flying in an airplane. This can be caused by storing the NiTek Duo with wet dive gear, which can touch its external electrical contacts and cause it to enter dive mode.
Chapter 3 Care and maintenance Summary This chapter provides care and maintenance and battery information for the NiTek Duo.
Care and maintenance Proper handling techniques The NiTek Duo is constructed to withstand the most demanding diving conditions. It is, however, a high precision instrument, which requires proper care. Caution: Failure to follow these handling techniques may result in damage to the NiTek Duo. • Do not store the computer in hot and/or humid environments. The pressure transducer is sensitive to both heat and humidity. If impaired, it may cause incorrect altitude or depth readings.
Care and maintenance • Do not use compressed air to dry the NiTek Duo • Do not use the NiTek Duo in hyperbaric chambers if the device is not fully submerged in water • Always rinse the computer with freshwater after use • Store the NiTek Duo in a cool, dry location. After diving, wipe the computer dry and store it in a location separate from other damp items.
Care and maintenance Low battery warning The battery that comes with the NiTek Duo is designed to last for up to three years under normal use. You may get more or less use from the battery depending on how often it is used and how it is cared for. Cautions • All NiTek Duo functions may cease within two to three days of the low battery symbol first appearing. Always have low batteries replaced promptly. • A depleted battery that is left in a NiTek Duo for a long period of time may leak.
Care and maintenance 2. Examine the battery and battery housing for signs of corrosion. Wipe off any sand or dirt from the cover and o-ring. 3. Remove the battery. 4. Replace the battery; making sure that the polarity is correct. For correct battery size, refer to “Specifications.” 5. Place a thin layer of silicone grease on the cover o-ring. 6. Screw the battery cover back into place. Do not over tighten. 7. Reset the time and date.
Care and maintenance 50 NiTek Duo Dive Computer User Manual
Index A accessing modes and screens · 11 activating back light · 13 alarms · 3 gauge mode · 22 max depth symbol · 15 max time symbol · 15 maximum depth · 15 maximum depth alarm · 18 maximum time · 15 algorithm · 5 altitude · 3, 5 altitude operation · 43 altitude symbols · 43 ascent rate · 27 log mode · 37 ascent rate warning · 30 ascent time · 33 log mode · 37 B back light · 4 activating · 13 battery · 5 low battery warning · 48 replacing · 48 Buhlmann · 5 button operation · 11 C care and maintenance · 45
Index primary screen · 26 secondary screen · 27 M F features and functions · 3 flying no-fly symbol · 42 FO2 default · 20 dealing with · 21 how it occurs · 21 FO2 percentages log mode · 37 fresh or salt water use setting · 18 fresh water · 15 G gas mixes changing underwater · 28 gas mixtures · 3 gauge mode · 34 changing screens underwater · 35 guage mode · 22 selecting · 22 I Imperial · 4, 15 maximum depth · 27 gauge mode · 35 log mode · 37 maximum depth alarm · 15 description · 18 gauge mode · 22 setti
Index oxygen limit index · 27, 42 oxygen limit index warning · 31 P PC transfer mode · 4, 40 entering · 40 percentages mix1 and mix2 · 15 plan mode · 24 PO2 limit warning · 30 profile · 4 profile mode · 38 viewing · 39 profile sampling rate · 15 description · 17 gauge mode · 22 setting · 17 R residual nitrogen · 24, 27, 33, 42 S safety factor · 14 description · 16 log mode · 37 setting · 16 safety information · 6 safety stop · 28 salt or fresh water use gauge mode · 22 salt water · 15 select button · 11 se
Index decompression warning · 32 default warning · 29 diving mode · 29 low battery warning · 48 oxygen limit · 31 54 PO2 limit warning · 30 water fresh or salt · 4 salt or fresh water use · 18 NiTek Duo Dive Computer User Manual
