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 Number 7454-95 Trademark Notice U.S. Divers® and Aqua-Lung® are registered tradmarks of U.S. Divers Co., Inc. Warranty U.S. Divers Co., Inc.
Pay special attention to warnings and cautions, which are denoted by this symbol: WARNINGS alert you to any procedure or situation that may result in serious injury or death. CAUTIONS alert you to any situation or technique that will result in damage to the product. Safety Considerations You must carefully read this entire manual before using your Monitor 3 Air. WARNING: Diving has many inherent risks. Decompression sickness is among the most serious of those risks.
The Monitor 3 Air is a technically advanced tool based on a biophysical model of decompression theory. However, neither it nor any other diving computer (or table) can actually monitor the physical changes that occur in your body as you dive. Each diver varies in his or her susceptibility to decompression sickness, and that susceptibility may vary from day to day. Decompression modeling is an inexact science; it is based, at least partly, on certain unproven assumptions.
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/decompression status must use their own computer. 8. If the Monitor 3 Air fails at any time during the dive, the dive must be terminated and appropriate procedures (including a slow ascent and a 3 to 5 minute safety stop) should be initiated immediately. 13.
Table of Contents Safety Considerations .............................................................. i Guidelines for Using the Monitor 3 Air ..................................... ii Introduction 1 What is a “Dive Computer” ....................................... 2 Definition of Compartments .................................................... 2 Multi-Level Diving ................................................................... 2 Diving Responsibly ...................................................
Diving at Altitude ..................................................... 29 Altitude sectors ..................................................................... 29 Exceeding the Altitude Limit .................................................. 30 Summary of Attention Messages and Alarms ......... 31 Attention Messages ............................................................... 31 Alarms ................................................................................... 33 Memory Mode 35 Overview .
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 important to understand the features and functions of the Monitor 3 Air. Before using the Monitor 3 Air, it is essential to read this manual in its entirety.
Introduction 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 NDT available.
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. of air time remaining and a digital readout of remaining air time. In addition, their are two warning icons: one for interrupted transmission and the other for high breathing rate.
Introduction Monitor 3 Air display zones and contact letter designations 5
THE TRANSMITTER The compact transmitter module screws into a standard 7/ " HP port. The transmitter automatically activates when 16 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 special code each time it transmits pressure information. The computer "listens" to the code, and, if it is the correct code, accepts the pressure information.
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 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: STEP 1 If your regulator is attached to a charged SCUBA cylinder, turn the valve handle to the closed position and vent any air in the regulator by pressing the second-stage purge button. Remove the regulator from the cylinder.
Section 1: Preparation 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 under the warranty. STEP 1 Fit your regulator to a charged SCUBA cylinder. DO NOT open the valve yet. STEP 2 Activate the Monitor 3 Air by touching contacts A&D.
Section 1: Preparation STEP 3 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 4 Touch contacts A and D as soon as “PAIr” appears (within 5 seconds). The computer will confirm with a beep and ‘PAIr” will stop flashing.
Section 1: Preparation STEP 5 The first cylinder pressure reading will be displayed within 15 seconds. 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 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 transmitter, new computer, or have the battery changed. Always check the cylinder pressure before every dive.
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 Preparation for the Dive STEP 3 Switch on the Monitor 3 Air by touching contacts A and D. Check the display to make sure all the display elements are lit. STEP 4 Open the cylinder valve. The transmitter switches on automatically when it senses pressure. 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).
Section 2: Diving with the Monitor 3 Air STEP 5 Check the cylinder pressure reading. The cylinder pressure reading appears about 10 seconds after turning on the valve. STEP 6 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 Functions During the Dive 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 the actual depth, depending on the salinity of the water.
Section 2: Diving with the Monitor 3 Air Dive Time Maximum Depth 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. Maximum depth is the deepest depth reached during the dive. It is only displayed when the actual depth is more than three feet shallower than the maximum depth.
Section 2: Diving with the Monitor 3 Air 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 ascent rate will display 50%. If you ascend at 67 ft/min the ascent rate will show 100%. If the ascent rate is 100% or more, the arrow appears.
Section 2: Diving with the Monitor 3 Air 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 slowly may cause heightened saturation of tissues and increase both decompression time and total ascent time.
Section 2: Diving with the Monitor 3 Air Cylinder Pressure 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 tool, to its limits. Avoid no-stop times of less than 3 minutes at any given depth.
Section 2: Diving with the Monitor 3 Air Graphic Air Time Remaining (ATR) Digital 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 filled to the 30 minute level, you have between 30 and 45 minutes of air time.
Section 2: Diving with the Monitor 3 Air 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 “J”-type valve is possible only if the reserve lever of the valve is in the open (down) position during the dive.
Section 2: Diving with the Monitor 3 Air Decompression Stop Information If you exceed the no-stop limits, the Monitor 3 will replace the no-stop time with the deepest (first) decompression 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 shallower decompression stop is displayed, along with its required stop time.
Section 2: Diving with the Monitor 3 Air Total Ascent Time SOS Mode 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. If you ignore your decompression stop and return to the surface (shallower than 4 feet) for more than three minutes, the Monitor 3 Air switches to SOS Mode. In SOS Mode, the computer displays SOS instead of current depth.
Section 2: Diving with the Monitor 3 Air Surface Mode Functions at the Surface Note: Surface mode will stay visible for 3 minutes. After that, the screen will go blank to save battery power. To reactivate the surface mode display, touch contacts A and D. 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.
Section 2: Diving with the Monitor 3 Air Wait-to-fly Time Wait-to-fly Recommendations Wait-to-fly time is the minimum amount of time you should wait before flying in a commercial airliner. Wait-tofly 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 serious injury or death from decompression sickness.
Section 2: Diving with the Monitor 3 Air Desaturation Time Surface Interval 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. Surface interval time is shown immediately after accessing Memory Mode. For more information on accessing Memory Mode, see page 38, steps 1 and 2.
Section 2: Diving with the Monitor 3 Air 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 repetitive dives, the surface interval should be planned long enough to reduce the risk of decompression sickness.
Section 2: Diving with the Monitor 3 Air Diving at Altitude Altitude sectors 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. Atmospheric pressure is influenced by altitude and weather.
Section 2: Diving with the Monitor 3 Air 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 there is an altitude indication while at sea level, or two computers differ by 2 altitude sectors, contact your U.S. Divers dealer for service.
Section 2: Diving with the Monitor 3 Air Summary of Attention Messages and Alarms End of no-stop time The Monitor 3 Air draws your attention to certain situations 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. To avoid making a decompression dive, a "0" flashes during the last minute of no-stop time to alert you to ascend to a shallower depth.
Section 2: Diving with the Monitor 3 Air High air consumption Lost transmission If the computer does not receive data from the transmitter, the antenna symbol is displayed, accompanied by two beeps. If this occurs frequently, check the position of the transmitter or computer. If situation persists for more than 40 seconds, air information will no longer be displayed. When there is a significant increase in the air consumption, the warning icon appears, accompanied by two beeps.
Section 2: Diving with the Monitor 3 Air Alarms Alarms are communicated to you by symbols, letters, or flashing icons. In addition, an acoustic warning sounds during the duration of the alarm. An alarm occurs in the following situations. Air Time Remaining = 0 The air supply may be insufficient to safely reach the surface. Start your ascent immediately.
Section 2: Diving with the Monitor 3 Air 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 with the cylinder pressure display. In Ready Mode or Surface Mode, it flashes in place of the tank pressure. This indicates battery charge is nearing 0%.
In this section: ☛ Activating Memory Mode ☛ Scrolling through logged dives
Section 3: Memory Mode Overview Downloading the Memory to a PC 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 removed.
Section 3: Memory Mode 37
Section 3: Memory Mode Activation STEP 1 STEP 2 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. Surface interval time appears when activated from Surface Mode 38 Touch Contacts A & D to confirm the selection. After a few moments, the information for the most recent logged dive appears.
Section 3: Memory Mode 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 was the first dive after a complete desaturation. Exiting Memory Mode To exit Memory Mode, touch contacts A&D.
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 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 diving organization. Recreational or sport scuba divers should not attempt decompression dives.
Section 4: Pre-Dive Planning Mode STEP 2 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 3 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 that depth. Note: If you want to stay longer than the no-stop time limit, proceed to "Planning a Decompression Dive" on page 46.
Section 4: Pre-Dive Planning Mode 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. Surface Mode 44 STEP 2 Touch contacts A & D to confirm the selection. The words "Add" and "Int" appear along with a flashing surface interval time.
Section 4: Pre-Dive Planning Mode 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 STEP 4 After adding the desired amount of surface interval time, touch contacts A & D. The word "run" flashes for a few moments, then the Monitor starts scrolling from 50 to 200 feet in 10-foot increments.
Section 4: Pre-Dive Planning Mode Planning a Decompression Dive Before planning a decompression dive, reread the import warning at the beginning of this section. STEP 2 Increase the dive time by touching contacts A & C. If you increase the dive time too much and want to reduce it, touch contacts A & B. Increase Time STEP 1 When the Monitor 3 Air scrolls to the desired depth, touch contacts A & D.
Section 4: Pre-Dive Planning Mode STEP 3 When you reach the desired dive time, release the contacts and, after a few moments, the Monitor 3 Air will display the new decompression information. You can then, as shown in step 2, increase and decrease the dive time as you wish. STEP 4 To return to the pre-dive scrolling, touch contacts A & D. If you want to return to Surface Mode or Ready Mode, touch contacts A & D for about three seconds.
Section 4: Pre-Dive Planning Mode 48
Section 5: Care & Maintenance Overview Care Before the Dive 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. The Monitor 3 Air’s plastic housing is made of a shock resistant resin. This housing protects the Monitor 3 Air from the normal bumps that occur when diving.
Section 5: Care & Maintenance 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. Annual Dealer Inspections & Factory Service Factory service was discontinued in 1997. Please contact the original manufacturer, Uwatec, at 800-467-2822.
Section 5: Care & Maintenance Operating Temperature The Monitor 3 Air operates normally between 12oF to 122oF (-10oC to 50oC). 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 exposed to direct sunlight or in a hot, confined space (like a car trunk). After the dive, cover the computer and keep it out of the sun.
Section 6: Reference Technical Specifications Operational Performance No-Decompression Model Depth Range: ................... 0-330 feet • ZH-L8 ADT Time Measurement: .......... 0-199 min.; Quartz timing • 8 tissue compartments, 5 to 640 minutes Air Pressure Range: .......... 3625 psi • Decompression stop depths at 10 to 80 feet in 10-foot increments Temperature Range: ......... 14oF to 122 oF Display: ............................
Section 6: Reference 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.
Section 6: Reference 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. This will help prevent the formation of microbubbles in the arterial circulation and minimizes formation of microbubbles in the venous circulation after the dive.
