U.S. Divers 2 Plus manual

Owner's Manual[...]

Copyright Notice This owner's manual is copyrighted, all rights reserved. It may not, in whole or in part, be copied, photocopied, reproduced, translated, or reduced to any electron medium or machine readable form without prior consent in writing from U.S. Divers Co., Inc. ©1995 U.S. Divers Co., Inc. Monitor 3 Air Owner's Manual, Part Nu[...]

Pay special attention to warnings and cautions, which are denoted by this symbol: Safety Considerations You must carefully read this entire manual before using your Monitor 3 Air. WARNING: Diving has many inherent risks. Decom- pression sickness is among the most serious of those risks. Even if you follow the instructions in this manual carefully, [...]

Guidelines for Using the Monitor 3 Air The following guidelines for using the Monitor 3 Air are derived from the latest medical research and the recom- mendations of the American Academy of Underwater Sciences for diving with dive computers. Following these guidelines will increase your safety while diving, but cannot guarantee that decompression s[...]

6 . The Monitor 3 Air is designed for dives made with compressed air only. Do not use the Monitor 3 Air for dives made with nitrox or other mixed gases. 7 . All divers using dive computers to plan dives and indicate or determine no-decompression/decompres- sion status must use their own computer. 8 . If the Monitor 3 Air fails at any time during th[...]

T able of Contents Safety Considerations .............................................................. i Guidelines f or Using the Monitor 3 Air ..................................... ii Intr oduction 1 What is a “Dive Computer” ....................................... 2 Definition of Compartments ................................................[...]

Diving at Altitude ..................................................... 29 Altitude sectors ..................................................................... 29 Exceeding the Altitude Limit .................................................. 3 0 Summar y of Attention Messages and Alar ms ......... 31 Attention Messages .........................[...]

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2 Introduction Congratulations on the purchase of your Monitor 3 Air dive computer. Our designers have condensed important dive planning information into a user-friendly dive instrument. By combining graphics with bold alphanumerics, we have created an easy-to-use computer that provides dive data at a glance. As with all diving equipment, it is imp[...]

Introduction 3 Multilevel diving is where the Monitor 3 Air excels. By continuously calculating the nitrogen absorption/release of all the compartments, the computer updates the amount of no-decompression time (NDT) you have left. As you ascend to shallower depths, the computer credits you with more allowable NDT; if you go deeper, it reduces the N[...]

4 Features of the Monitor 3 Air The Monitor 3 Air is made up of two compact units: the computer/display unit which is usually worn on the wrist, and the high pressure (HP) transmitter which is screwed into the regulator first-stage HP port. THE COMPUTER SCREEN The Monitor 3 Air has a large liquid crystal display (LCD) and features large numbers and[...]

Introduction 5 Monitor 3 Air display zones and contact letter designations[...]

6 THE TRANSMITTER The compact transmitter module screws into a standard 7 / 16 " HP port. The transmitter automatically activates when it senses pressure from the cylinder. Once activated, it sends pressure information via a low frequency radio wave to the wrist unit. One of the unique features of the transmitter is that it sends along a speci[...]

In this section: ☛ Attaching the Transmitter to the Regulator ☛ Pairing the Wrist Unit with the Transmitter ☛ Using the Monitor 3 Air Without the Transmitter ☛ Checking battery power[...]

Section 1: Preparation 8 Attaching the Transmitter to Your Regulator Upon purchasing the Monitor 3 Air have your Authorized U.S. Divers Dealer attach the transmitter to your first-stage regulator. If this is not possible, follow the simple steps listed below to do it yourself: Thread the transmitter into the HP port of the first-stage until finger-[...]

Section 1: Preparation 9 CAUTION: DO NOT use the transmitter as a carrying handle. Doing so may damage the transmitter requiring its replacement. If the first-stage is attached to a cylinder, make sure to secure the cylinder so it doesn’t fall over and damage the transmitter (or regulator). A transmitter damaged due to user neglect is not covered[...]

Section 1: Preparation 10 Place the Monitor 3 Air wrist unit directly against the transmitter. Turn on the cylinder valve. Within six seconds the message “PAIr” will appear flashing in the upper tank pressure display. STEP 3 STEP 4 Touch contacts A and D as soon as “PAIr” appears (within 5 seconds). The computer will confirm with a beep and[...]

Section 1: Preparation 11 The first cylinder pressure reading will be displayed within 15 seconds. STEP 5 If the procedure is not successful, a FAIL message will appear. If this happens, close the cylinder valve, purge all air from the regulator and repeat the procedure.[...]

Section 1: Preparation 12 Once paired, the Monitor 3 Air will always display the tank pressure of the cylinder to which the transmitter is connected, whenever it is in range. Note: The pairing procedure only needs to performed once, before the first use. After that, the only time you need to perform the pairing procedure is when you use a new trans[...]

In this section: ☛ Preparation for the dive ☛ Functions during the dive ☛ Functions at the surface ☛ Summary of Messages and Alarms[...]

Section 2: Diving with the Monitor 3 Air 14 Preparation for the Dive Note: The following preparation instructions assume that the transmitter is installed correctly into your first-stage regulator (see page 8) and that it is paired with the Monitor 3 Air computer (see page 9). WARNING: If the Monitor 3 Air transmitter is not correctly installed or [...]

Section 2: Diving with the Monitor 3 Air 15 Check the cylinder pressure reading. The cylinder pressure reading appears about 10 seconds after turning on the valve. The Monitor 3 Air is now in Ready Mode. The computer switches to Dive Mode after entering the water and submerging below four feet. The depth indication may be delayed for a few seconds.[...]

Section 2: Diving with the Monitor 3 Air 16 Current Depth Current depth is displayed in one-foot increments down to a maximum of 330 feet. When the depth is two feet or less, the depth display is replaced with three dashes. Note: Depth measurement is based on freshwater. When diving is salt water, the depth displayed will be slightly greater than t[...]

Section 2: Diving with the Monitor 3 Air 17 Dive Time Dive time, which is displayed in minutes, is the amount of time spent below a depth of 4 feet. While the dive time is running, the colon to the right of the number flashes in one-second intervals. Maximum dive time displayed is 199 minutes. Note: If a dive lasts longer than 199 minutes, dive tim[...]

Section 2: Diving with the Monitor 3 Air 18 Ascent Rate The optimal ascent rate varies between 23 and 67 ft/min. depending on the depth. Ascent rate is displayed as a percentage of the allowable ascent rate (rounded to the nearest 10 %). For example, if the allowable ascent rate at the current depth is 67 ft/min, and you ascend at 33 ft/ min, the a[...]

Section 2: Diving with the Monitor 3 Air 19 Some Notes on ascent rate: - The Monitor 3 Air may require a decompression stop due to an improper ascent rate, even if you stay within the no-stop limits. - Decompression time necessary for the prevention of microbubbles can increase greatly if the ascent rate is exceeded. - At great depth, ascending too[...]

Section 2: Diving with the Monitor 3 Air 20 WARNING: There is an acoustic alarm if no-stop time is less than one minute. In this last minute, the no-stop display shows a flashing 0. In order to prevent a decompression dive, you must ascend immediately. WARNING: It is unsafe diving practice to “push” the Monitor 3 Air, or any other decompression[...]

Section 2: Diving with the Monitor 3 Air 21 Graphic Air Time Remaining (ATR) The graphic air time remaining box gives you, at a quick glance, the amount of air you have left. As your air time lowers, the box empties. For example, if the box is filled up to the 45 minute level, you have between 45 and 60 minutes of air time remaining; if the box is [...]

Section 2: Diving with the Monitor 3 Air 22 WARNING: Never allow the ATR to go below three minutes. If the ATR goes below three minutes there is a danger of insufficient air supply for the ascent as well as an increased risk of decompression sickness and serious injury or death may result. WARNING: Correct calculation of ATR when using a reserve or[...]

Section 2: Diving with the Monitor 3 Air 23 Decompression Stop Information If you exceed the no-stop limits, the Monitor 3 will replace the no-stop time with the deepest (first) decom- pression stop depth (in feet) along with the amount of decompression time (in minutes) at that depth. When a decompression stop has been completed, the next shallowe[...]

Section 2: Diving with the Monitor 3 Air 24 Total Ascent Time Total Ascent Time is the addition of all the decompression stop times plus the amount of time it takes to ascend from the current depth to the first decompression stop. Note: Total ascent time is calculated with an optimal ascent rate of 100% and normal workload. High workloads and diffe[...]

Section 2: Diving with the Monitor 3 Air 25 Functions at the Surface Upon surfacing After reaching the surface, the Monitor 3 automatically switches into wait-mode for five minutes. This is the amount of time necessary to recognize the end of the dive. The five minute delay allows you to come to the surface to orient yourself, then resume the dive.[...]

Section 2: Diving with the Monitor 3 Air 26 Wait-to-fly Time Wait-to-fly time is the minimum amount of time you should wait before flying in a commercial airliner. Wait-to- fly time is displayed in hours and is denoted by the no-fly symbol immediately above it. WARNING: Flying while the Monitor 3 Air is still displaying wait-to-fly time may lead to[...]

Section 2: Diving with the Monitor 3 Air 27 Desaturation Time Desaturation time is the amount of time it takes to completely off-gas any residual nitrogen in your system. Desaturation time is displayed in hours and minutes. Desaturation time display Surface Interval Time Surface interval time is shown immediately after accessing Memory Mode. For mo[...]

Section 2: Diving with the Monitor 3 Air 28 Microbubble Warning Repetitive diving may cause microbubbles to accumulate in the lungs if the surface interval between dives is not long enough. Ignoring decompression stops or an excessive ascent rate can also lead to bubble formation. In order to reduce the risk of decompression sickness for future rep[...]

Section 2: Diving with the Monitor 3 Air 29 Diving at Altitude The Monitor 3 Air measures the atmospheric pressure even while in Sleep Mode. If the computer detects a higher altitude, it automatically switches on and displays the adaptation time. This is the time after which your body is considered desaturated and stable at the given altitude. Alti[...]

Section 2: Diving with the Monitor 3 Air 30 Even the smallest differences in the pressure sensors can cause two computers at the same altitude to display different altitude sectors. (Notice how the altitude sectors overlap in the illustration.) These differences are not meaningful and do not interfere with the operation of the computer. However, if[...]

Section 2: Diving with the Monitor 3 Air 31 Summary of Attention Messages and Alarms The Monitor 3 Air draws your attention to certain situa- tions and warns you of unsafe diving practices. Attention messages and alarms are always visual and acoustical while underwater; they are only optical at the surface except for the decompression alarm. Attent[...]

Section 2: Diving with the Monitor 3 Air 32 Lost transmission If the computer does not receive data from the trans- mitter, the antenna symbol is displayed, accompanied by two beeps. If this occurs frequently, check the position of the transmitter or com- puter. If situation persists for more than 40 seconds, air information will no longer be displ[...]

Section 2: Diving with the Monitor 3 Air 33 Fast ascent Reduce your ascent rate (see page 18 for more details on ascent rate) Air Time Remaining = 0 The air supply may be insufficient to safely reach the surface. Start your ascent immediately. Alarms Alarms are communicated to you by symbols, letters, or flashing icons. In addition, an acoustic war[...]

Section 2: Diving with the Monitor 3 Air 34 Low computer battery While diving, "bAt' alternates with the maximum depth display. During Surface Mode or Ready Mode, "bAt" flashes in the maximum depth position. This indicates battery charge is nearing 0%. Low transmitter battery While diving, the "bAt" message alternates [...]

In this section: ☛ Activating Memory Mode ☛ Scrolling through logged dives[...]

Section 3: Memory Mode 36 Overview The Monitor 3 Air wrist unit is able to display the details of the last 19 dives. Any dive that lasts two minutes or longer is entered into memory. After the memory is filled with all 19 dives, the oldest dive is deleted for each new dive entered. All the dive information stays in memory until the battery is remov[...]

Section 3: Memory Mode 37[...]

Section 3: Memory Mode 38 Activation STEP 1 From Ready Mode or Surface Mode , touch contacts A & C. The computer will emit one beep and the Memory Mode icon will appear in the mode zone. If activating from Surface Mode, the current surface interval also appears. STEP 2 Touch Contacts A & D to confirm the selection. After a few moments, the [...]

Section 3: Memory Mode 39 Scrolling through Logged Dives To scroll back through the memory (towards the oldest dive), touch contacts A & C. To scroll forward through the memory (towards the most recent dive), touch contacts A & B. Scroll back through logged dives Note: The absence of a previous surface interval means that the logged dive wa[...]

Section 3: Memory Mode 40[...]

In this section: ☛ Activation from Ready Mode ☛ Activation from Surface Mode ☛ Planning a Decompression Dive[...]

Section 4: Pre-Dive Planning Mode 42 Overview The Monitor 3 Air has a built-in dive planner that allows you to plan both no-stop dives and decompression dives. The planner takes into account the temperature of the most recent dive and altitude. WARNING: Planned decompression dives violate the responsible diving practice standards of every major div[...]

Section 4: Pre-Dive Planning Mode 43 Touch contacts A & D to confirm the selection. The word RUN will flash for about five seconds and then start scrolling through the available time-depth combinations. STEP 2 The Monitor scrolls from 50 to 200 feet in 10-foot increments. For each depth the computer gives the maximum allowable no-stop time at t[...]

Section 4: Pre-Dive Planning Mode 44 Activation from Surface Mode STEP 1 From Surface Mode , touch contacts A & B. The computer will emit one beep and the Dive Plan Icon will appear in the mode zone. STEP 2 Touch contacts A & D to confirm the selection. The words "Add" and "Int" appear along with a flashing surface inter[...]

Section 4: Pre-Dive Planning Mode 45 STEP 3 If you do not want to add any additional surface time, go to step 4. If you do want to add surface time, touch contacts A & C. If you add too much surface time and want to decrease it, touch contacts A & B. Increase Time Note: Surface interval time increases in 15 minute increments for the first 6[...]

Section 4: Pre-Dive Planning Mode 46 Planning a Decompression Dive Before planning a decompression dive, reread the import warning at the beginning of this section. STEP 1 When the Monitor 3 Air scrolls to the desired depth, touch contacts A & D. The word “Add” appears in the depth zone, the flashing dive time is now one minute more than th[...]

Section 4: Pre-Dive Planning Mode 47 When you reach the desired dive time, release the contacts and, after a few moments, the Monitor 3 Air will display the new decompres- sion information. You can then, as shown in step 2, increase and decrease the dive time as you wish. STEP 3 To return to the pre-dive scrolling, touch contacts A & D. If you [...]

Section 4: Pre-Dive Planning Mode 48[...]

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Section 5: Care & Maintenance 50 Overview The Monitor 3 Air is a robust instrument designed to withstand the rigors of SCUBA diving. However, you still need to protect it from shock, extreme heat, chemical attack, and tampering. Even though the Monitor 3 Air’s material is tough and durable, it is susceptible to chemical attack and scratches. [...]

Section 5: Care & Maintenance 51 Care After the Dive CAUTION: If the Monitor 3 Air transmitter is not attached to a first-stage regulator while soaking (explained below), make sure that water is not allowed to enter the high pressure inlet. Water entering the transmitter may cause damage to the internal components. After each day of diving, soa[...]

Section 5: Care & Maintenance 52 Operating Temperature The Monitor 3 Air operates normally between 12 o F to 122 o F (-10 o C to 50 o C). You may notice the liquid crystal display (LCD) becoming sluggish at extremely low temperatures. This is normal and will not affect the computer’s accuracy. It is possible to damage the electronics if left [...]

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Section 6: Reference 54 Technical Specifications Operational Performance Depth Range: . . . . . . . . . . . . . . . . . . . 0-330 feet Time Measurement: . . . . . . . . . . 0-199 min.; Quartz timing Air Pressure Range: . . . . . . . . . . 3625 psi Temperature Range: . . . . . . . . .1 4 o F to 122 o F Display: . . . . . . . . . . . . . . . . . . . [...]

Section 6: Reference 55 ZH-L8 ADT Calculation Model The Monitor 3 Air uses a new calculation model known as the ZH-L8 ADT. This model uses eight compartments or "tissue" groups with half-times ranging from 5 to 640 minutes. This calculation model is based on the most current research conducted by the late Dr. A.A. Buhlmann. Most computer [...]

Section 6: Reference 56 time will also assist those local areas of impaired circulation to desaturate with less risk of decompression sickness. The calculation of microbubbles results in altered ascent instructions. If microbubbles are assumed to be present based on the data used by the Monitor 3 Air, the ascent rate is reduced to 23 feet/minute. T[...]