Diving 32% Nitrox with "Air" Algorithms

[Centrals]

uh, it's been a while since I've used it but if I recall correctly
my Aladin pro Nitrox of approx the same vintage has a setting for PO2. If i were going for a less or more conservative result I'd change that.

Are there any nitrox computers that don't have an adjustable PO2 setting?

PPO2 setting is different from conservatism setting. And it is NOT readily changed by user, mine was set up at 1.6 at the shop.
Beside changing of PPO2 eg. 1.6 to 1.5 does not affect the ndl. You just cannot go deeper otherwise the alarm will sound.

The whole argument so far is the setting of the dc should be identical to the gas that the diver is breathing.
Pro Nitrox has 2% increment on the nitrox input, so you would eg. punch in 32 instead of 34 if the analyser shown 33%?

 

[FishWatcher747]

My Aqualung I300c has a binary CF Conservative Factor setting, The computer runs the Z+ algorithm. If turned on the CF instead of calculating at the current elevation it pretends one is diving 3000 ft higher than the current elevation.

How does this compare to setting a more expensive Buhlman computer CF to 70/30?

From the manual:

Doc. 12-7874-r06 (11/27/17)13
DIVE FEATURES
© Aqua Lung International, Inc. (2017)
ASC BAR GRAPH
The ASC Bar Graph provides a visual representation of ascent speed (i.e., an ascent speedometer). When the
ascent is faster than the recommended 9 mpm (30 fpm), all segments and the message SLO (slow) flash until the
ascent is slowed.
# OF SEGMENTS ASCENT RATE,
MPM (FPM)
0 0 - 3 (0 - 10)
1 3.1 - 4.5 (11 - 15)
2 4.6 - 6 (16 - 20)
3 6.1 - 7.5 (21 - 25)
4 7.6 - 9 (26 - 30)
5 > 9 (> 30)
N2 BAR GRAPH
The N2 Bar Graph represents your relative No Decompression or Decompression status. The first four seg-
ments represent No Decompression status and the fifth indicates a Decompression condition. As your Depth and
Elapsed Dive Time increase, segments are added. As you ascend, segments recede indicating that additional No
Decompression time is available. The i300C monitors multiple theoretical nitrogen compartments simultaneously
and the N2 Bar Graph displays the one that is in control of your dive at any given time.
ALGORITHM
The i300C utilizes the Z+ algorithm to calculate nitrogen tissue loading. To create even greater margins of safety
with respect to decompression, a Conservative Factor as well as No Decompression Deep and Safety Stops can
be included for No Decompression dives.
CF (CONSERVATIVE FACTOR)
When the CF is set to On, the dive time remaining, No Deco/O2 MIN, which are based on the algorithm and used
for N2/O2 calculations and displays relating to Plan Mode, will be reduced to the values available at the altitude
level that is 915 m (3,000 ft) higher than the actual altitude at activation. Refer to the charts in the back of this
manual for dive times

 

[Belzelbub]

PPO2 setting is different from conservatism setting. And it is NOT readily changed by user, mine was set up at 1.6 at the shop.
Beside changing of PPO2 eg. 1.6 to 1.5 does not affect the ndl. You just cannot go deeper otherwise the alarm will sound.

Which computer are you talking about? If the shop (dive shop) is able to set the PPO2, then I'm pretty sure the user can as well. Veo 180NX manual discusses it and indicates that this can be set anywhere from 1.2 to 1.6 in increments of 0.1. Factory default is 1.6, but it is user adjustable.

Single button computer, so probably not as intuitive as many other computers, but can be changed by the user. This is not a setting that needs to be changed each dive.

The whole argument so far is the setting of the dc should be identical to the gas that the diver is breathing.
Pro Nitrox has 2% increment on the nitrox input, so you would eg. punch in 32 instead of 34 if the analyser shown 33%?

Yes. You'd use the lower setting for the O2., but respect the MOD for the actual mix. This is the safest route, though most dive computers I've seen made in this century allow 1% increments.

 

[Centrals]

Which computer are you talking about? If the shop (dive shop) is able to set the PPO2, then I'm pretty sure the user can as well. Veo 180NX manual discusses it and indicates that this can be set anywhere from 1.2 to 1.6 in increments of 0.1. Factory default is 1.6, but it is user adjustable.

Single button computer, so probably not as intuitive as many other computers, but can be changed by the user. This is not a setting that needs to be changed each dive.

Yes. You'd use the lower setting for the O2., but respect the MOD for the actual mix. This is the safest route, though most dive computers I've seen made in this century allow 1% increments.

The PPO2 in Uwatec Aladin Pro Nitrox has to be set by the shop because of the use of hardware. Do you know how it can be done by the user?
Setting of PPO2 does not affect the ndl.
2% increment in Uwatec Pro Nitrox. Most does not mean ALL.

 

[Belzelbub]

The PPO2 in Uwatec Aladin Pro Nitrox has to be set by the shop because of the use of hardware. Do you know how it can be done by the user?

Nope. Changing PPO2 should be something that can be done by the user. I have no idea what hardware the shop has for that computer. I’m surprised if they still have that hardware.

Setting of PPO2 does not affect the ndl.

I know that. I never said that it did.

2% increment in Uwatec Pro Nitrox. Most does not mean ALL.

I’m aware of what most means. I haven’t messed with every computer out there. Of all the computers I have used or looked into, 1% was the norm. Probably was a reason for 2% increments back in 1995 (memory limitations?), but I can’t think of a good reason today.

 

[Divin'Papaw]

The PPO2 in Uwatec Aladin Pro Nitrox has to be set by the shop because of the use of hardware.

Wow. That's just an awful design. I'll try not to take my Shearwaters for granted.

 

[wetb4igetinthewater]

Wow. That's just an awful design. I'll try not to take my Shearwaters for granted.

I don't believe in shooting horses that are lame, but I sure as heck do believe in shooting dive computers that are lame.

 

[grantctobin]

Wow. That's just an awful design. I'll try not to take my Shearwaters for granted.

Admittedly, it came out in the mid 90s. 95?

 

[Divin'Papaw]

Admittedly, it came out in the mid 90s. 95?

And it’s still in use?!

 

[tursiops]

The PPO2 in Uwatec Aladin Pro Nitrox has to be set by the shop because of the use of hardware. Do you know how it can be done by the user?

The setting is done with the DataTrak software and the right interface cable.