Changeset 7b44cf2 in subsurface

Feb 5, 2015, 11:27:35 AM (3 years ago)
Dirk Hohndel <dirk@…>
Mtest, android_test, dcDownload, foratdotde, gitMerge, gitdebug, gitpictures, ios, master, mergeKirigamiPort, pictimeshift, resolutionIndependence, spinner, testTomaz, testing, v4.5-branch
willem ferguson <willemferguson@…> (02/05/15 10:42:21)
Dirk Hohndel <dirk@…> (02/05/15 11:27:35)

User manual: small updates

A section on multicylinder dives has been added.
Just to warm LongJohnSilver?'s heart, a short section on pSCR has been added.
Please feel free to add to the pSCR section, LongJohn?.
Replaced the sidemount figure with obsolete mean depth line.

Fixes #827
Fixes #828

Signed-off-by: willem ferguson <willemferguson@…>
Signed-off-by: Dirk Hohndel <dirk@…>

3 added
2 edited


  • Documentation/user-manual.txt

    rbd9a443 r7b44cf2  
    825825(top right-hand panel).
    827828*Cylinders*: The cylinder information is entered through a dialogue that looks
    828829like this:
    16361637=== Logging special types of dives
     1640==== Multicylinder dives
     1642_Subsurface_ easily handles dives involving more than one cylinder. Multicylinder diving usually happens
     1643(a) if a diver does not have enough gas for the complete dive in a single cylinder; (b) if the diver
     1644needs more than one gas mixture because of the depth or the decompression needs of the dive. For this reason
     1645multicylinder dives are often used by technical divers who dive deep or long. As far
     1646as _Subsurface_ is concerned, there are only two types of information that need to be provided:
     1648- *Describe the cylinders used during the dive* This is performed in the *Equipment tab* of
     1649  the *Dive Info* panel, as xref:cylinder_definitions[described above]. Enter the cylinders one by one,
     1650  specifying the characteristics of the cylinder and the gas composition within each cylinder.
     1652- *Record the times at which switches from one cylinder to another was done:* This is information
     1653  provided by some dive computers (provided the diver indicated these changes to the dive computer
     1654  by pressing specific buttons). If the dive computer does not provide the information, the diver has to
     1655  record these changes using a different method, e.g. writing it on a slate.
     1657- *Record the cylinder changes on the dive profile*: If the latter option
     1658  was followed, the diver needs to indicate the gas change event by right-clicking at the appropriate point
     1659  in time on the *Dive Profile* panel and indicating the cylinder to which the change was made. After
     1660  right-clicking, follow the context menu to "Add gas change" and select the appropriate cylinder from
     1661  those defined during the first step, above (see image below). If the
     1662  *tank bar* button in the ttolbar has been activated, the cylinder switches are also indicated in the
     1663  tank bar.
     1665Having performed these tasks, _Subsurface_ indicates the appropriate use of cylinders in the dive profile.
     1666Below is a multi-cylinder dive, starting off with EAN28, then changing cylinders to EAN50 after 26 minutes
     1667to perform decompression.
     1669image::images/multicylinder_dive.jpg["FIGURE: Multicylinder profile",align="center"]
    16381671==== Sidemount dives
    1640 _Subsurface_ easily handles dives involving more than one cylinder. Sidemount dive logging involves
    1641 three steps:
    1643 - *During the dive, recording cylinder switch events*. Since sidemount diving normally involves two
     1673Sidemount diving is just another form of multicylinder diving, often with both or all cylinders having
     1674the same gas mixture. Although it is a popular configuration for cave divers, sidemount
     1675diving can be performed by recreational divers who have completed the appropriate training. Sidemount
     1676dive logging involves, exactly as with multicylinder dives, above, three steps:
     1678- *During the dive, record cylinder switch events*. Since sidemount diving normally involves two
    16441679  cylinders with air or with the same gas mixture, _Subsurface_ distinguishes among these different
    16451680  cylinders. In contrast, most dive computers that allow gas switching only distinguish among different
    16671702This section gives an example of the versatility of _Subsurface_ as a give logging tool.
     1706==== Semi-closed circuit rebreather (SCR) dives
     1710Passive semi-closed rebreathers (pSCR) comprise a technical advance in diving equipment that
     1711recirculates the breathing gas that a diver breathes, while removing carbon dioxide from
     1712the exhaled gas. While a small amount (typically a tenth) of the exhaled breathing gas is released into the water,
     1713a small amount of fresh gas is released from the back gas cylinder (typically containing nitrox).
     1714A diver, using a single cylinder of breathing gas can therefore dive for much longer periods than
     1715using a recreational open-circuit configuration. With pSCR equipment, a very small amount of breathing
     1716gas is released every time the breather inhales. With active SCR (aSCR) equipment, in contrast, a small amount of
     1717breathing gas is released continuously from the back cylinder.
     1719To log pSCR dives, no special procedures are required, just the normal steps outlined above:
     1721- Select pSCR in the _Dive Mode_ dropdown list on the *Dive Info* panel.
     1723- pSCR diving often involves gas changes, requiring an additional cylinder.
     1724  Define all the appropriate cylinders as described above
     1725  and indicate the cylinder/gas changes as described above in the section on xref:S_MulticylinderDives[multicylinder dives].
     1727If a pSCR _Dive Mode_ has been selected, the dive ceiling for pSCR dives is adjusted for the oxygen
     1728drop accross the mouthpiece which often requires longer decompression periods. Below is a dive profile
     1729of a pSCR dive using EAN36 on the back cylinder and oxygen for decompression. Note that this dive lasted
     1730over two hours.
     1732image::images/pSCR_profile.jpg["FIGURE: pSCR profile",align="center"]
    16701737==== Closed circuit rebreather (CCR) dives
    18431910The profile also includes depth readings for the peaks and troughs in the graph.
    18441911Thus, users should see the depth of the deepest point and other peaks. Mean depth
    1845 is marked with a horizontal red line.
     1912is plotted as a grey line, indicating mean dive depth up to a particular moment during the dive.
    26992766** _Show unused cylinders in Equipment Tab_: This checkbox allows display of information about unused cylinders when viewing the *Equipment Tab*. Conversely, if this box is not checked, and any cylinders entered using the *Equipment Tab* are not used (e.g. there was no gas switch to such a cylinder), then these cylinders are omitted from that list.
    2701 ** _Show average depth_: Activating this checkbox causes _Subsurface_ to draw a red line across
    2702    the dive profile, indicating the mean depth of the dive.
     2768** _Show average depth_: Activating this checkbox causes _Subsurface_ to draw a grey line across
     2769   the dive profile, indicating the mean depth of the dive up to a particular point in time during
     2770   that dive. Normally this is a u-shaped line indicating the deepest average depth just before the
     2771   ascent.
    27042773* *Misc*:
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