heinrichs weikamp OSTC 3 User manual

User manual
Open Source Dive Computer

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Contact
For any questions relating to your
OSTC 3, please contact us via…
• internet forum:
forum.heinrichsweikamp.com
• E-Mail:
[e-mail]
• per mail:
heinrichs weikamp
Adlerstraße 7
79098 Freiburg im Breisgau
Germany
Contact

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Thank you for choosing a heinrichs
weikamp dive computer.
Using open source software for full
transparency, combined with state-of-
the-art hardware and a robust housing
made of aluminum, the OSTC 3 is your
instrument of choice for technical diving.
The rmware hwOS supports you both
at scubadiving and rebreather diving
with extensive functions and options.
For trimix diving you can use up to ve
gases, in the rebreather mode you can
choose between xed setpoints or the
monitoring with an external sensor.
You can t the deco models to your own
needs. They also use the calculation with
gradient factors. In addition the OSTC 3
oers an apnea and gauge mode as well
as a digital compass.
In the new version of the OSTC 3 data like
logbook information or updates can be
easily transferred with Bluetooth. Take
also notice of the large supply of logbook
programs and other software.
The development of heinrichs weikamp
dive computer is permanently going on.
Use the rmware updates to keep your
OSTC 3 always up to date. Get it for free
at:
www.heinrichsweikamp.com
You can use the OSTC 3 intuitively. But to
become familiar with its functions and
to use it in the best way, we recommend
you to read this manual carefully.
We hope you enjoy diving with your new
OSTC 3 dive computer!
Your OSTC 3

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Common advices......................................... 6
Technical status ..................................... 6
About this manual ................................ 7
Functions overview ............................... 8
Safety Advices ............................................10
Requirements .......................................10
Before every dive .................................12
While diving ..........................................14
Safe use of the OSTC 3 .......................16
Environmental conditions ................17
Before rst use ..........................................18
Handling .................................................19
Modes of operation ............................21
Modes of diving ...................................24
Compass calibration ...........................26
Surface Mode .............................................28
Display in surface mode ...................28
Menu functions ...................................30
Logbook ...............................................32
Gas setup ............................................35
CCR Setup ............................................41
Simulator ............................................46
Deco mode ..........................................51
Settings ................................................57
Dive mode ...................................................65
Displays in dive mode ........................65
Menu functions ...................................70
Gaslist ..................................................71
Setpoint change................................73
Bailout ..................................................73
Reset average .....................................74
Baring ...................................................75
Ascent rate ..........................................76
Maintenance ..............................................77
Housing ..................................................77
Bungee ....................................................78
Replacing the battery .........................79
Spare parts ............................................81
Readout the dive computer ..................82
Bluetooth connection ........................83
Software for the OSTC 3 ....................84
Updating the rmware .....................85
Technical data ............................................86
Disposal ........................................................87
Content

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Technical status
This manual corresponds to the techni-
cal status of OSTC 3 and its rmware as
of December 2015.
OSTC 3, its rmware and the documen-
tation are subject to technical changes
without notice.
The OSTC 3 rmware (integrated soft-
ware) is an ongoing development. To
make the best use of OSTC 3, we advise
you to use the latest stable rmware
available on the heinrichs weikamp
website: www.heinrichsweikamp.com
Standard settings
Unless noted dierently, the information
in this manual refers to OSTC standard
settings.
For important settings, the OSTC 3
shows an asterisk * behind the current
setting, if the current setting is dierent
from the default setting.
About this manual
Special markings
!Warning
indicates a situation that carries a signi-
cant risk or injury.
Caution
indicates a situation that carries a risk of
damage to the device.
Note
indicates additional information for ad-
vanced OSTC 3 user.
Terms of use
Copyright © heinrichs weikamp
Copying or reusing this manual or parts
of this manual is not allowed without
the written permission of heinrichs
weikamp.
Common advices

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Functions overview
Your dive computer OSTC 3 assists you
with the following functions:
Display
Diving depth and duration according
to EN 13319, maximum diving depth,
ambient temperature, duration and
depth of planned decostops, time to de-
saturation based on diving depth and
duration
Oxygen surveillance in CCR diving (using
the optional hw HUD or the ppO2
monitor)
Additional informations (e.g. tilt-com-
pensated compass, average depth, stop-
watch, ppO2, CNS)
Planning
Congure and check gas mixes as well as
setpoints and sensor data in CCR mode,
calculate a decoplan in the simulator
Record
Time, duration, depth prole, tempera-
ture, reference pressure and time of de-
saturation
Requirements
The most important factor for safe diving
is a competent and well trained diver.
This dive computer is intended for expe-
rienced divers. That implies:
It is necessary that your diving education
also included decompression diving.
Sucient knowledge about the laws
of physics in diving is required. It may
harm your health if you rely on a wrong
congured dive computer.
Do not use this dive computer, if you
don’t know or understand the settings
and displayed information of OSTC 3.
If necessary, you must be able to nish
your dive safely without a dive computer.
Don’t adjust decompression parameters
if you are not aware of their meanings.
Safety Advices

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Before every dive
Plan your dive.
Set up a dive plan independently from
OSTC 3 and take it with you when diving.
Make sure that your OSTC 3 is ready for
use and correctly configured.
Always conrm the following questions
before diving:
Stable firmware?
Use only stable rmware provided by
heinrichs weikamp. It has been tested
and allows a proper and reliable perfor-
mance of OSTC 3.
Configured correctly?
Check the settings of your OSTC 3. If
necessary, adjust the settings according
to your dive plan and equipment.
Battery full?
Check the battery status using the
battery indicator on the display. To
ensure reliable performance through-
out your dive, the battery must be su-
ciently high. A new lithium primary cell
(SAFT LS14500) allows up to 50 hours of
diving, a quality alkaline AA battery (e.g.
Duracell Ultra Power) about 20 hours, a
lithium 1,5V AA battery (e.g. Energizer
E2) about 30 hours.
Device waterproof?
Ensure that the battery compartment is
properly closed and watertight. Check
the housing for cracks or damages which
might allow water to intrude.
Safely attached?
Make sure that your OSTC 3 can be
fastened safely using either the bungees
or a suitable alternative.
Display messages?
Check the signals of OSTC 3. Do not dive
if your dive computer displays a warning.
Check the cause of the warning.

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While diving
Take a backup system with you
While diving, always carry a backup
system to measure duration and depth
of your dive independently from OSTC 3.
Take a sufficiently long surface break
before diving again.
The OSTC 3 doesn’t indicate how long to
wait before the next dive. Please follow
the guidelines you were taught during
your dive training.
Take the OSTC 3 with you on every repeat
dive – don’t lend it to anyone.
A correct calculation of tissue saturation
requires that your OSTC 3 is:
• congured correctly
• used on every dive
• only used during your own dives (and
not shared with other divers).
Caution
Saturation data is lost when updating
the OSTC 3 rmware or in the unlikely
event of a failure. In these cases, do not
dive any further until tissue saturation
has returned to normal level.

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Safe use of the OSTC 3
Do not modify the hardware. Modi-
cations to the hardware of OSTC 3
can damage its proper function and
can damage the watertightness of its
housing.
Only the bungee backplate and the cap
of the battery compartment can be
removed. There is no other way to open
the housing without damaging the
device.
Caution
Surpassing the maximum water depth
of 120 metters may cause malfunction
or permanent damage of the device.
Environmental conditions
Store the OSTC 3 in a cool, dry place. Per-
missible temperature range for use and
storage: between -5 °C and 40 °C.
Make sure that the used battery is
suitable for the ambient temperature to
be expected in your dives. For cold water
diving (under 10°C) we recommend the
use of a lithium battery.
Note
Decompression calculations and depth
display are always based on the actual
surface pressure. So if you are diving in
mountain lakes, no further settings are
needed. OSTC 3 automatically adapts to
the actual surface pressure.

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heinrichs weikamp delivers the OSTC 3
ready for use with a high quality lithium
battery (Saft LS14500). But nevertheless
check the battery status before using the
dive computer the rst time.
Before diving, you need to adjust some
settings as described in this manual. Fa-
miliarize yourself with the OSTC 3. It is
recommended that you read this manual
carefully.
Handling
Operate the OSTC 3 with the two buttons
Set/MENU and ENTER on the left and
right side of the housing. The force re-
quired to push the buttons is indepen-
dent to ambient pressure. You can push
and hold the button in order to change
a data. You always have to push only one
button.
Push the left button SET/MENU to enter
the menu. To select a menu entry, push
SET/MENU repeatedly until the cursor
marks the required menu item. From the
item on the bottom, the cursor jumps
Before rst use
SET/MENU ENTER

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back to the top with the next push. To
conrm push ENTER.
In some menus you will nd the entry
more. Select this entry to access the next
menu page with more menu items.
To change the setting of a menu item,
push ENTER repeatedly until the re-
quired value is displayed. You can also
hold-down the ENTER button in order to
change a value.
Wet connector system (optional):
Connect up to three oxygen sensors
using the hwHUD or the ppO2 monitor.
The connection is based on a bre
optic cable that can be removed and
connected also under water.
Modes of operation
OSTC 3 has three modes of operation
and switches automatically between
them: Surface mode, dive mode and
sleep mode.
Surface mode
In surface mode you can adjust the set-
tings for the next dive, adjust the base
settings of the OSTC 3 and read recorded
dive data.
To wake up the OSTC 3, push one of the
buttons SET/MENU or ENTER.
In surface mode the display shows gene-
ral information as time, date, temper-
ature, ambient pressure and battery
status. After a dive the display also shows
tissue saturation and the no y time.

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Dive mode
The OSTC 3 automatically switches into
dive mode when it is at least 1,6 meter
below the surface for ve seconds.
Note
For a pre-dive-check of the functions
and settings, we recommend to switch
on the dive computer manually before
every dive.
In dive mode the display shows current
diving depth, dive time, maximum
depth, the currently selected gas (in CCR
diving the setpoint or the values of the
sensors), decompression information
and additional information.
It is not possible to switch underwater
from dive mode to surface mode. You
cannot change the base settings while
diving. Note that exceptions apply to the
apnea mode.
Sleep mode
When the OSTC 3 isn’t operated at the
surface, it switches into sleep mode after
two minutes to save battery.
In sleep mode the display is turned o.
Ambient pressure is measured at regular
intervals. After a dive, decompression
calculation continues.

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Modes of diving
In the main menu you can choose under
deco mode, if you want to use the OSTC 3
for scuba diving, rebreather diving, apnea
diving or as depth gauge. The chosen
dive mode I shown permanently on the
main display (OC, CC, apnea, gauge)
OC (open circuit): Use this dive setting
with regular dive equipment (open
circuit). This setting is pre-set on your
OSTC 3.
CC (closed circuit): Use this dive setting
with a closed circuit rebreather.
The decompression calculation model is
Bühlmann ZH-L16 without or Bühlmann
ZH-L16+GF with gradient factors (read
more on page 52). You can switch from
ZH-L16 to ZH-L16+GF under Decotype.
Apnoe: Use this dive setting for apnea
diving or snorkeling.
In apnea mode the OSTC 3 serves as a
depth gauge. Additionally displayed are
ambient temperature and elapsed time
since starting the dive. Decompression
and saturation calculation are switched
o. In apnea mode the OSTC 3 remains
in dive mode even when diving at low
depths. You can switch into surface mode
at any time by pushing SET/MENU. Push
ENTER to conrm the QUIT? question.
The OSTC 3 switches automatically from
apnea mode into surface mode after a
15 minutes delay and above a depth of
1 meter.
Gauge: In this setting, OSTC 3 serves as
a depth gauge. Decompression and satu-
ration calculation are switched o.

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Compass calibration
OSTC 3 has a tilt-compensated electro nic
compass. Like all other electronic com-
passes it must be calibrated before use.
The calibration compensates aberration
that can be caused by the battery.
It is recommended to compensate the
compass after battery change (it is not
necessary if you use the same battery
type) or if your dive computer shows big
deviations in the heading reading.
For an exact heading, the calibration of
the compass is absolutely necessary.
Activate the compass calibration via
Settings > More > Compass Calibration.
After starting the calibration menu,
move the dive computer slowly around
each axis. Do this a number of times
within 60 seconds. After this while the
calibration ends automatically. During
the calibration routine the OSTC 3 shows
X-, Y- and Z-axis.
Note
The order of the axis rotation is not im-
portant. Keep OSTC 3 away from any
metallic object during the calibration
process (at least 50 centimeters).
y
z

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Display in surface mode
Permanent items
In the surface mode the OSTC 3 shows
the following items permanently:
• ambient pressure, clock, date
• temperature
• battery level
• dive mode: open circuit (OC), closed
circuit (CC), gauge or apnea
• sensor data (CCR diving)
• after the dive: No y time, desatura-
tion, and surface interval, warnings for
missed deco and too high CNS
Selectable items
In the middle part of the display you
can see extra information in the custom
view. You can switch them with the right
button.
• personal text (up to 60 characters)
• compass
• gaslist (OC) or setpoints (CC)
• current settings: deco type, gradient or
saturation factors, time of future TTS,
last deco, salinity
• desaturation diagram (After the dive,
you can see the approximate tissue
saturation in the desaturation diagram.
The 16 types of tissue according to the
Bühlman model are arranged hori-
zontally. The fastest tissue is on top,
the slowest is below. When the line is
longer, the tissue is more saturated.)
Surface Mode

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Menu functions
In surface mode you can adjust the set-
tings to prepare the next dive, adjust the
base settings of OSTC 3 and review your
dives in the logbook.
To open the menu in surface mode push
SET/MENU. With the left button you can
scroll through the menu. To select an
item push ENTER.
Logbook: Recorded data from recent
dives
OC Gas setup: Set up your gas mix for
scubadiving or your bailout gases for CCR
diving. You can congure up to ve gases
(air, helium, oxygen up to 100 percent)
CCR Setup: Settings for rebreather diving
(CCR). Congure setpoints and diluent
gases
Simulator: Calculate deco and simulate
the dive mode
Deco mode: Settings for deco calcula-
tion and dive modes (open circuit, closed
circuit, gauge or apnea) of the OSTC 3.
Settings: Settings for time, language,
display brightness, compass
Exit: Exit the main menu
These functions are described in the fol-
lowing chapters of this manual.

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Logbook
The OSTC 3 records data during every
dive. It can be retrieved from the
logbook. The OSTC 3 stores data of up to
255 dives with a total duration of 500 to
1000 hours. The exact number of records
depends on the overall size of data. If the
memory is full, existing records will be
overwritten, starting with the oldest.
Note
If you want to secure your recorded dive
data, you can connect the OSTC 3 via
Bluetooth to a computer and readout
the data.
Logbook entries are sorted in chronologi-
cal order, starting with the most recent
entry. Every entry shows position index,
date, maximal depth and dive time.
To see details of the selected dive, press
ENTER. The dive prole and details page
shows up. The details page also shows
position index, date, maximum diving
depth, duration, minimum ambient
temperature, ambient pressure above
water, desaturation time, the used gases
and additional information of the dive.
Switch from depth diagram to details
page with the left button.

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Note
Via Settings > Display Settings > Logbook
Offset you can put in your own number
of dives. It will be shown instead of the
numbers of dives which are stored in the
dive computer (page 60).
OC Gas setup
Use gas setup to congure presets for up
to ve gases for scubadiving as well as
bailout gases for rebreather diving . You
can switch between these presets when
you change your gases while diving.
The presets are marked like this: Air for
compressed air (21% oxygen) and Nx for
Nitrox (e.g. a mix of Nitrox 31 is shown
as Nx31). 100% oxygen is shown as O2.
If the oxygen value is lower than 21%
and no helium is added, the warning Err
appears. This gas mix is unusual.

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Choose a gas in the menu OC gas setup
and push ENTER to see details or to
change values.
Type
Each mix can be set to the following
type:
First: The rst gas which is used when
the dive starts. Only one gas can be
marked as rst. If there is only one gas
active, it will be automatically rst gas.
In the view the rst gas is marked with *.
Each gas can be marked as rst gas.
Travel: Gases used for descending or as
bottom gas.
Deco: Gases used for decompression
Disabled: Gas is disabled and is not
taken into account for the decompres-
sion prognosis.
Disabled gases are shown in blue letters.
Note
The rst gas is used when starting the
dive.
All gases (even disabled ones) can be
chosen underwater.
The OSTC 3 always computes the tissue
load and the decompression scheme
using the selected gas. It takes all deco
gases in account for the decompression
phase.
The change of deco gases with cong-
ured change depth will be advised un-
derwater.

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Setup mix
For every gas you can set the percentage
of oxygen and helium.
Select O2+ or O2- to change the percent-
age of oxygen or He+ or He- to change the
percentage of helium. Repeatedly push
ENTER (or hold down the ENTER button)
until the required value is displayed. For
reference, the OSTC 3 displays the calcu-
lated maximum opera ting depth (MOD)
and equivalent narcotic depth (END) for
your mix.
Change depth
To set the operation depth for your deco
gases, select Depth+ or Depth-. The
chosen operation depth will be shown
in the rst line of the display. It will turn
red if the change depth is deeper than
the maximum operation depth (MOD).
Use Reset to MOD to reset the value to
the MOD. The change depth can only be
congured for deco gases, not for travel
gases.
Examples
Dive with only one gas: Congure one
gas, for example gas 1 as rst. Set up
the mix using the submenu “setup” mix.
Disable the other gases (Type: disabled).
Dive with one additional decompression
gas: Setup the rst gas. Enable one other
gas as deco and setup your gas mix.
Disable the remaining gases.
Dive with two decompression gases:
Setup another gas to deco and congure
the second deco mix.
Dive with two decompression gases and
one travel/bottom gas: Additionally to
the rst gas and the two decompression
gases, congure a fourth gas as travel.
Disable the unused gas.