Do you have a question about the PERDIX and is the answer not in the manual?
Questions and answers
Abraham Potappel
April 15, 2025
Suddenly the Pertix A! does not show an umore the tank pressure, all other info still is shown.
The device is used with a Shearwater transmitter.
When downloaded into the computer, the desktop display does show the tank pressure graph.
1 comments:
Mr. Anderson
April 15, 2025
The Shearwater Perdix AI may stop displaying tank pressure while still showing other information if there is an issue with the transmitter (T1 or T2) or its communication. Possible causes include:
- Transmitter is not paired or has lost pairing with the computer. - Transmitter battery is low or dead. - Interference or signal obstruction between the transmitter and the computer. - The dive computer is not in AI mode or is not configured to display transmitter pressure.
Other functions may continue to operate normally because they do not rely on the transmitter.
Shearwater Perdix Operating Instructions Table of Contents Introduction ����������������������������������������������������������������������������������������������������������������5 Feature List ��������������������������������������������������������������������������������������������������������������5 Installing Straps or Bungee Cord ����������������������������������������������������������������������������6 Straps ���������������������������������������������������������������������������������������������������������������������6 Bungee Cord ������������������������������������������������������������������������������������������������������������7 Turning On �����������������������������������������������������������������������������������������������������������������8 Auto-On �������������������������������������������������������������������������������������������������������������������8 Buttons �����������������������������������������������������������������������������������������������������������������������9 The Main Screen ������������������������������������������������������������������������������������������������������10 Color Coding ����������������������������������������������������������������������������������������������������������10 The Top Row ����������������������������������������������������������������������������������������������������������11 The Center Row �����������������������������������������������������������������������������������������������������13...
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Shearwater Perdix Operating Instructions Table of Contents (continued) Define Gas ���������������������������������������������������������������������������������������������������������33 Dive Planner�������������������������������������������������������������������������������������������������������35 Conservatism �����������������������������������������������������������������������������������������������������37 NDL Display �������������������������������������������������������������������������������������������������������38 Brightness ����������������������������������������������������������������������������������������������������������40 Dive Log Menu �������������������������������������������������������������������������������������������������������41 Display Log ��������������������������������������������������������������������������������������������������������41 Upload Log ���������������������������������������������������������������������������������������������������������41 Edit Log Number ������������������������������������������������������������������������������������������������41 System Setup ��������������������������������������������������������������������������������������������������������42 Mode Setup ��������������������������������������������������������������������������������������������������������43 Deco Setup ��������������������������������������������������������������������������������������������������������45...
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Shearwater Perdix Operating Instructions DANGER This computer is capable of calculating deco stop requirements� These calculations are at best a guess of the real physiological decompression requirements� Dives requiring staged decompression are substantially more risky than dives that stay well within no- stop limits�...
The Shearwater Perdix is an advanced technical diving computer for open and closed circuit divers� Although we strive to make the Perdix easy enough to use without reading the manual, please take some time to read this manual to get the best performance from your new computer�...
Shearwater Perdix Operating Instructions Installing Straps or Bungee Cord The Perdix includes mounting points for either two elastic straps or two bungee cords� Both types are included in the box� Straps Install the elastic straps as shown in the image below� The buckles feature a locking mechanism to prevent them from inadvertently loosening�...
We find that the knot at right works well� This knot has the nice feature of creating loops that stay wide open while putting the Perdix on your wrist� Tip: Use two pieces of cord When using the bungee cord, always create two independent loops so that a single break does not result in a lost dive computer�...
So the Perdix will automatically turn-on when about 0�9 m (3 ft) underwater when at sea level� If at higher altitude, then the Perdix auto-on will occur at a deeper depth� For example, when at 2000 m (6500 ft) altitude the atmospheric pressure is only about 800 mbar�...
Shearwater Perdix Operating Instructions Buttons Two piezo-electric buttons are used to change settings and view menus� Except for turning the Perdix on, all operations are simple single button presses� MENU (left) button SELECT (right) button Don’t worry about remembering all the button rules below� Button hints make using the Perdix easy�...
Shearwater Perdix Operating Instructions The Main Screen Top Row Depth, Time & Deco Stops Center Row PPO2 Bottom Row Mode, Gas & Deco Info The main screen shows the most important information needed for technical diving� Color Coding Color coding of text draws attention to problems or unsafe Sample warning - situations�...
Shearwater Perdix Operating Instructions The Top Row The top row shows depth and time information Depth DEPTH Imperial: In feet (no decimal places)� Metric: In meters (displays with 1 decimal place up to 99�9m) in feet DEPTH 69.7 Note: If the depth shows a...
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90ft stop depth By default the Perdix uses a 10ft (3m) last stop depth� At this setting, you may perform the last stop at 20ft (6m) with no penalty� The only difference is that the predicted time-to-surface will be shorter than the actual TTS since off-gasing is occurring slower than expected�...
These limits can be adjusted in the Adv. Config 2 menu. For CC mode, the Perdix only uses fixed PPO2 setpoints. There is no option to connect the Perdix directly to oxygen sensors for direct monitoring of loop PPO2� This option is available in the Petrel 2 Fischer and DiveCAN models�...
Shearwater Perdix Operating Instructions Center Row Configuration In most modes, the center row displays can be customized� Configure the center row in the System SetupCenter Row Menu� The left and right positions can be set to display the following: Option...
Shearwater Perdix Operating Instructions The Bottom Row The bottom row displays the current mode, gas and decompression information� Circuit Mode The current breathing configuration. One of: OC = Open circuit (when CC available, displays in Yellow indicate bailout condition) CC = Closed circuit...
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Shearwater Perdix Operating Instructions GF99: The raw percentage of the Bühlmann allowable GF99 supersaturation at the current depth� @+5: The predicted time-to-surface (TTS) if you were to stay at the current depth for 5 more minutes� Time-to-Surface (TTS) The time-to-surface in minutes� This is the current time to ascend to the surface including the ascent plus all required deco stops�...
Pressing the MENU (left) button will also return to the main screen� The info screen content is optimized for each mode� Set the Perdix to the mode you will be using (e�g� OC) and step through the info screens to get familiar with the content�...
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Shearwater Perdix Operating Instructions Average Depth Displays the average depth of the current dive, updated once per second� When not diving, shows the average depth of the last dive� Average Depth in Atmospheres (AvgATM) The average depth of the current dive, measured in absolute AvgATM 2.52...
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Shearwater Perdix Operating Instructions Diluent PPO2 Only displayed in CC mode� Displays in Flashing Red when DilPPO2 the partial pressure of the diluent is less than 0�19 or greater than 1�65� When performing a manual diluent flush, you can check this value to see what the expected PPO2 will be at the current depth�...
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1O13 1O11 The current pressure is only shown on the surface� SURF The surface pressure is set when the Perdix is turned on� If the Altitude setting is set to SeaLvl, then surface pressure is always 1013 millibars� Temperature: The current temperature in degrees Fahrenheit (when depth TEMP 73°F...
Shearwater Perdix Operating Instructions Compass The compass features: • 1° resolution • ± 5° accuracy • Smooth, high-speed refresh rate • User set heading marker with reciprocal • True North (declination) adjustment • Tilt compensated to ± 45° Viewing the compass When enabled, the compass is viewed by pressing the SELECT (right) button once�...
Shearwater Perdix Operating Instructions Menus Press MENU (left) button to step through the menus� Press SELECT (right) button to execute command or enter sub-menu� Menus display on the bottom row� MENU button SELECT button Perdix Turns Off MENU button SELECT...
Shearwater Perdix Operating Instructions The following sections show the menu structure in various operating modes� Open Circuit Menu Structure Main Screen Turn Off Surface only Sub-Menus Select Gas Dive Setup+ Conserv. Define Gas NDL Display Dive Planner+ Brightness Dive Log+...
Shearwater Perdix Operating Instructions Simple Example Dive Here is an example of a simple OC air dive� It will help to introduce DEPTH TIME SURFACE 4hr39mn the screen displays as the diver progresses, the dive starts, the depth GasPPO2 increases� The display is showing the computer programmed for open circuit (OC) air�...
Shearwater Perdix Operating Instructions Gauge Mode Gauge Mode turns the Perdix into a simple depth and time display (a�k�a� a bottom timer)� Change to Gauge Mode in the System SetupMode Setup menu� Since decompression tissues are not tracked in Gauge Mode, changing to or from Gauge Mode resets the deco tissues�...
Shearwater Perdix Operating Instructions Decompression and Gradient Factors The basic decompression algorithm used for the computer is Bühlmann ZHL-16C� It has been modified by the use of Gradient Factors that were developed by Erik Baker. We have used his ideas to create our own code to implement it� We would like to give credit to Erik for his work in education about decompression algorithms, but he is in no way responsible for the code we have written�...
PPO2 value of a setpoint, use the Dive Setup menu. This menu item performs a manual switching of PPO2 setpoint� In the System SetupAuto SP Switch menu, the Perdix can be setup to automatically perform setpoint switches at programmable depths�...
Shearwater Perdix Operating Instructions Select Gas DEPTH TIME SURFACE This menu item allows you to pick a gas from the gases you have created� The selected gas will be used either as the breathing gas in open circuit mode, or the diluent in closed circuit mode�...
Shearwater Perdix Operating Instructions Select Gas Menu Styles Two styles of Select Gas menus are available, Classic and New� Change between the two styles in the Adv. Config 1 menu. Classic Style Select Gas The classic Select Gas style is as described on the previous page�...
Shearwater Perdix Operating Instructions Switch to OC/CC DEPTH TIME SURFACE Depending on the current computer setting, this selection will show as either “Switch CC > OC” or “Switch OC > CC”� Switch CC > OC Pressing SELECT will select the displayed mode for decompression calculations�...
Shearwater Perdix Operating Instructions DEPTH TIME SURFACE Another press of MENU will increment it again� Edit Low SP O.5 Change Save DEPTH TIME SURFACE If SELECT is pushed, the currently displayed setpoint will be selected, and the display will return to the “Edit Low SP” menu item�...
Shearwater Perdix Operating Instructions Define Gas The function allows you to set up 5 gases in Closed Circuit and 5 DEPTH TIME STOP TIME gases in Open Circuit� You must be in Open Circuit to edit open circuit .85 .86 .84 gases, and you must be in Closed Circuit to edit closed circuit diluents�...
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Shearwater Perdix Operating Instructions DEPTH TIME STOP TIME Pushing MENU will continue to increment the gas number� .85 .86 .84 2 OC On 5O/OO Change Save Note: The “A” denotes the active gas� You cannot delete the DEPTH TIME STOP TIME active gas�...
In closed-circuit (CC) mode, also calculates open-circuit (OC) bail-out (BO)� SETUP Uses the current gases programmed into the Perdix, as well as the current GF low/high settings� VPM-B dive planning is available on units with the optional VPM-B unlock� Deco profile is computed for the current circuit mode (CC or OC).
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Shearwater Perdix Operating Instructions The Dive Planner does not provide thorough validation of the profile. For example, it does not check for nitrogen narcosis limitations, gas usage limitations, CNS percentage violations, or isobaric counter-diffusion risks due to sudden helium switches� The user is responsible for ensuring a safe profile is followed.
Shearwater Perdix Operating Instructions The final result screen shows the total dive time, the time spent on deco and final CNS%. Results Summary Screen If no decompression is required, no table will be shown� Instead, the total No-Decompression- Limit (NDL) time in minutes, at the given bottom depth will be reported� Also, the gas quantity required to surface (bailout in CC) will be reported�...
Shearwater Perdix Operating Instructions NDL Display DEPTH TIME STOP TIME The NDL Display option allows you to display four different values during the dive� The display can be changed during the dive to NDL Display NDL provide different information� Next Edit Pushing SELECT will make the NDL display editable.
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Shearwater Perdix Operating Instructions This number can be used in several ways� First, it can be used to calculate an aggressive ascent that still has some justification in decompression science. For example, if a diver were to lose a significant portion of their gas and needed to get shallow fast, they could ascend until they reached a gradient of 90, then stop until it dropped to 80, then ascend to 90 again, etc�...
Shearwater Perdix Operating Instructions Brightness The display brightness has three fixed brightness settings plus an DEPTH TIME STOP TIME Auto mode� The fixed options are: Brightness Auto • Cave: Lowest brightness, suitable for dark environments� Exit Edit • Low: Low brightness for long battery life�...
TIME STOP TIME The dive log number can be edited� This is useful if you want the Perdix log numbers to match your lifetime dive count� Edit Log Number At the “Edit Log Number” prompt, press SELECT to begin Next Edit editing�...
Shearwater Perdix Operating Instructions System Setup DEPTH TIME STOP TIME System Setup contains configuration settings together in a convenient format for updating the configuration before a dive. System Setup System setup cannot be accessed during a dive� However, many of the settings are also available during the dive in a single line interface�...
This is why OC is shown as a yellow warning when CC mode is available� When changing to or from Gauge mode, the decompression tissues are cleared� This is because when in Gauge mode the Perdix does not know what gas you are breathing� Salinity Water type (salinity) affects how the measured pressure is converted to depth�...
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CEIL Salinity Salt PPO2 Mode Low SP High SP On the Perdix this value cannot be edited and is always "Int" (internal Edit Edit Next PPO2 setpoints) Low and High Setpoints The Low and High PPO2 Setpoints are only available when CC is enabled�...
Shearwater Perdix Operating Instructions Deco Setup Deco Model May just show Bühlmann ZHL-16 with gradient factors model, or it ‣ Deco Setup may allow you to switch between GF and various types of VPM-B� The Deco Model choices will be available if you have unlocked VPM-B�...
If you ascend shallower than 50ft then re-descend deeper than 50ft again, the automatic setpoint switch will occur again� The Perdix enforces a 20 ft (6m) gap between switch up and switch down depths to prevent rapid automatic switching between setpoints for small depth changes�...
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Flip Screen always 1013 mBar (1 atmosphere)� Change Save If the Perdix measures the surface pressure to be less than 965 mbar, then the Altitude setting will be forced to "Auto" and cannot be changed� Determination of Surface Pressure Accurate depth measurements and decompression calculations require knowing the ambient atmospheric pressure at the surface�...
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This function displays the contents of the screen upside down� The Flip Screen is of limited use on the Perdix model, but can be used if you wish to wear the Perdix such that the button are on the top of the device�...
Shearwater Perdix Operating Instructions Compass Setup Compass View The Compass View settings can be set to: • Off: The compass is disabled� • 60°, 90°, or 120°: Sets the range of the compass dial that is visible on the main screen� The actual amount of arc that there is room for on the sceen is 60°, so this may feel the...
Calibration of the compass may be needed if the accuracy drifts over time or if a permanent magnet or ferromagnetic metal (e�g� iron or nickel) object is mounted very close to the Perdix� To be calibrated out, such an object must be mounted with the Perdix such that it moves along with the Perdix�...
The final ‘System Setup’ option is ‘Reset to Defaults’. This will reset System Setup all user changed options to factory settings and clear the tissues on 14-Aug-2O12 Date the Perdix� ‘Reset to Defaults’ cannot be reversed� 12:28PM Time Unlock Load Upgrade Note: This will not delete dive logs, or reset dive log numbers�...
Shearwater Perdix Operating Instructions Advanced Configuration 1 Advanced Config Advanced configuration contains items that will be used infrequently and can be ignored by most users� They provide more detailed Enter Adv. Config configurations. Reset Adv. Config System Info Battery Info The first screen allows you to enter the advanced configuration area, or to set the advanced configurations settings to their default.
Start a Bluetooth connection by selecting the Upload Log menu� The Perdix screen will switch from ”Initializing” to “Wait PC” which will have a countdown� Now go back to the Shearwater Desktop� Click start from the open “Update Firmware Box”, or “Download Log.”...
A small diagram on the bottom of the Perdix shows the proper orientation. Accepted battery types The Shearwater Perdix can accept a wide variety of AA sized batteries� The Perdix can accept any AA sized (or 14500 size) battery that outputs a voltage between 0�9V and 4�3V�...
Battery Types After changing the battery, a screen will prompt for the battery type to be entered� The Perdix attempts to guess what type of battery is being used� If the battery type is incorrect, it should be manually edited�...
The clock (time and date) is saved to permanent memory every 16 seconds when the Perdix is on, and every 5 minutes when off� When the battery is removed, the clock stops running� Once the battery is replaced, the clock is restored to the last saved value (so it is best to remove the battery while the Perdix is on for lowest error)�...
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Shearwater Perdix Operating Instructions For quick battery changes, the un-powered time interval is not significant. However, if the battery is removed shortly after a dive and then remains out for a long period, then residual tissue loading will remain when the battery is replaced� If you have not been diving for more than 4 days, it is safe to reset the tissues to their default levels (System Setup->Reset to Defaults->Tissues Only)�...
Shearwater Perdix Operating Instructions Error Displays The system has several displays that alert to error conditions� Limitations of Alarms All alarm systems share common weaknesses� They can alarm when no error condition exists (false positive)� Or they can fail to alarm when a real error condition occurs (false negative)�...
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Shearwater Perdix Operating Instructions Error Description Solution Use a slow ascent rate� Monitor The ascent was sustained at faster for symptoms of DCS� Use extra Fast ascent than 10m/min (33 feet/min)� conservatism for future repetitive dives� The decompression tissue inert...
Do not wash under high pressure jets of water as it may cause damage to the depth sensor� Store the Perdix dive computer out of direct sunlight in a cool, dry and dust free environment� Avoid exposure to direct ultra-violet radiation and radiant heat�...
Shearwater Perdix Operating Instructions Specifications Specification Perdix Model Operating Modes OC Tec OC Rec OC/CC (internal PPO2) Gauge Decompression Model Bühlmann ZHL-16C with GF VPM-B and VPM-B/GFS (optional) Display Full color 2�2" QVGA LCD with always on LED backlight Pressure (depth) sensor...
Shearwater Perdix Operating Instructions FCC Warning a) USA-Federal Communications Commission (FCC) This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of FCC Rules� These limits are designed to provide reasonable protection against harmful interference in a residential installation�...
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Do you have a question about the PERDIX and is the answer not in the manual?
Questions and answers
Suddenly the Pertix A! does not show an umore the tank pressure, all other info still is shown. The device is used with a Shearwater transmitter. When downloaded into the computer, the desktop display does show the tank pressure graph.
The Shearwater Perdix AI may stop displaying tank pressure while still showing other information if there is an issue with the transmitter (T1 or T2) or its communication. Possible causes include:
- Transmitter is not paired or has lost pairing with the computer.
- Transmitter battery is low or dead.
- Interference or signal obstruction between the transmitter and the computer.
- The dive computer is not in AI mode or is not configured to display transmitter pressure.
Other functions may continue to operate normally because they do not rely on the transmitter.
This answer is automatically generated