Question for those using a petrel/perdix. Mode and nitrox % quickly

[TT_Vert]

So I have not used this computer is a good 5 years and I recently update the firmware to the latest version. Lots of neat new stuff. I like the OC tech mode and the ability to configure the center row extensively. The one thing I do NOT like about is that I have to pre-define gasses. So when I'm in nitrox mode I can just to to gas and define the percentage very quickly. In OC mode I have to select a pre-defined gas. The problem is a nitrox fill may be 31.4% or 32.6% and in nitrox mode I can quickly go to gas and modify it up/down. In OC tech I am stuck w/ what I've already defined. I know I can just add a new gas to the list and enable it but it's annoying. Is there any way to allow quick mods of gas contents AND retain the nice OC tech UI? First world problems, I know.

Thanks much,

Dave

 

[Badger7]

So I have not used this computer is a good 5 years and I recently update the firmware to the latest version. Lots of neat new stuff. I like the OC tech mode and the ability to configure the center row extensively. The one thing I do NOT like about is that I have to pre-define gasses. So when I'm in nitrox mode I can just to to gas and define the percentage very quickly. In OC mode I have to select a pre-defined gas. The problem is a nitrox fill may be 31.4% or 32.6% and in nitrox mode I can quickly go to gas and modify it up/down. In OC tech I am stuck w/ what I've already defined. I know I can just add a new gas to the list and enable it but it's annoying. Is there any way to allow quick mods of gas contents AND retain the nice OC tech UI? First world problems, I know.

Thanks much,

Dave

May not be as big of an issue as you're expecting? You define gasses based on whole number percentages, so its not like you would change your gas from 31.5% to 32.3%, as long as your nitrox mix is within one percent of your intended 32%, its all 32%.

You don't want to have gasses enabled that you won't be taking with you on that dive, so why not just define like 21%, 26%, 32%, 50% and 99% (there is no 100% option either evidently), and when you're prepping for the next dive just go into dive setup, and enable the gas(es) you'll be using that dive and disable the ones you wont?

If you're only use one gas at a time, I admit there is a little back and forth. To change from 32% to 21%, if you only have one enabled, you need to go into dive setup, enable 21%, then back up to the top of the menu, and set that as your active gas, then you need to back into dive setup and disable 32%. OC Tech mode isn't quite as user friendly to set up when you're only diving one gas, but I do really like the layout and the information density, so for me worth the extra minute to enable, set active and disable the unused gas.

 

[TT_Vert]

May not be as big of an issue as you're expecting? You define gasses based on whole number percentages, so its not like you would change your gas from 31.5% to 32.3%, as long as your nitrox mix is within one percent of your intended 32%, its all 32%.

You don't want to have gasses enabled that you won't be taking with you on that dive, so why not just define like 21%, 26%, 32%, 50% and 99% (there is no 100% option either evidently), and when you're prepping for the next dive just go into dive setup, and enable the gas(es) you'll be using that dive and disable the ones you wont?

If you're only use one gas at a time, I admit there is a little back and forth. To change from 32% to 21%, if you only have one enabled, you need to go into dive setup, enable 21%, then back up to the top of the menu, and set that as your active gas, then you need to back into dive setup and disable 32%. OC Tech mode isn't quite as user friendly to set up when you're only diving one gas, but I do really like the layout and the information density, so for me worth the extra minute to enable, set active and disable the unused gas.

What i was doing was setting OC gasses that I "may" use and just selecting them in the gas area. Not sure if that is actually going to backfire on me? I'm not planning on switching gases at any point during any dives I will be doing w/ this computer and I planned to do exactly as you mention. I figured it would be easier to just define 5 gasses I'll use or likely see when testing a fill (basically 21%, EAN30,32,34 and 36). I suppose I could just define them all and disable the other 4 I won't use on that fill. But to do that, I first need to go into setup | OC gasses | then back out vs. just going to gas and manually entering my % of oxygen like in air/nitrox modes. I did just find that if i disable all but one gas and then select another gas it will auto enable that gas. But now I have two gases enabled. The computer won't auto switch gases on me will it? Does it just mess w/ potential deco calcs? If not, I could literally pick a gas on the list of enabled gases and just not change it. If it does change for a better gas, I'll just deal w/ this little annoyance. It'll become second nature eventually. On the LOB we're doing we'll likely have similar blends each tank but we'll see I guess.
Dave

 

[NothingClever]

I know I can just add a new gas to the list and enable it but it's annoying.

I’m diving 8-12 times a month with my Perdix and find that it’s pretty routine to be in my gas menu but don’t find it annoying. I leave my normoxic and deco mixes programmed in (but inactived when diving a rec profile) and still have flexibility to quickly change my EANx mix.

I think once you’re back in the swing of things, you won’t hardly think about, rather like putting your car keys in your pocket, locking/unlocking the car, etc.

Also, are you specifying what Nitrox you want or just taking what the charter gives you? If you dive a lot, you can be in the driver’s seat to tell the charter what blend you want (and hopefully the fill station attendant is on his game to provide what you want).

If you’re getting your own fills in your own tanks, you’re ironing out even more wrinkles.

The other option is to forego using a technical computer for recreational dives and buy a simpler recreational DC.

 

[grantmac]

You absolutely must not have gasses active which you are not carrying. It will assume they are available for deco and your TTS/deco obligation will be out to lunch.

 

[TT_Vert]

I’m diving 8-12 times a month with my Perdix and find that it’s pretty routine to be in my gas menu but don’t find it annoying. I leave my normoxic and deco mixes programmed in and still have flexibility to quickly change my EANx mix.

I think once you’re back in the swing of things, you won’t hardly think about, rather like putting your car keys in your pocket, locking/unlocking the car, etc.

Also, are you specifying what Nitrox you want or just taking what the charter gives you? If you dive a lot, you can be in the driver’s seat to tell the charter what blend you want (and hopefully the fill station attendant is on his game to provide what you want).

If you’re getting your own fills in your own tanks, you’re ironing out even more wrinkles.

The other option is to forego using a technical computer for recreational dives and buy a simpler recreational DC.

No doubt it'll be simple, i was just hoping there may be an easier way. TBH, I have to assume we are taking whatever the mix we are given is on this LOB. We are diving the great barrier reef and some of the diving is pretty deep so I'm going to have to watch my MOD. Given they are taking us to these places and providing the mix, perhaps they're just giving us EAN32. That or they go by a 1.60 PPO2 which I'm not going to be doing.

You absolutely must not have gasses active which you are not carrying. It will assume they are available for deco and your TTS/deco obligation will be out to lunch.

That's sort of what I thought, thanks for clarifying that.

Dave

 

[NothingClever]

Didn’t realize it was a LOB. I think you’ll find yourself at the mercy of the crew’s talent and the quality of fill station but if you have a chance to set the EANx blend for the week, I think 32% offers the best flexibility.

 

[NothingClever]

You absolutely must not have gasses active which you are not carrying. It will assume they are available for deco and your TTS/deco obligation will be out to lunch.

Edited my post above. Probably a bad assumption on my part that folks understand to only activate those gases they’ll have on the actual dive. Concur that leaving 18/45 or 99 activated for a recreational profile (!) will dork up the computations.

 

[TT_Vert]

Edited my post above. Probably a bad assumption on my part that folks understand to only activate those gases they’ll have on the actual dive. Concur that leaving 18/45 or 99 activated for a recreational profile (!) will dork up the computations.

Thanks, I sort of figured that from reading the latest manual but wasn't entirely sure of what the behavior would be. i turned all gases off but EAN 32 for now.

Didn’t realize it was a LOB. I think you’ll find yourself at the mercy of the crew’s talent and the quality of fill station but if you have a chance to set the EANx blend for the week, I think 32% offers the best flexibility.

Yeah given the depth some of these dives are alleged to be, 32 is likely the highest I'd want to go and also very likely all they'd offer. We're on our own during these dives so I doubt they'd even offer EAN36 when they know some of these dives are to 100'+ Maybe it's 100' w/ a shovel, i don't know.

Dave

 

[Blackcrusader]

Didn’t realize it was a LOB. I think you’ll find yourself at the mercy of the crew’s talent and the quality of fill station but if you have a chance to set the EANx blend for the week, I think 32% offers the best flexibility.

In Maldives I got one Nitrox mix at 29%. I just left my setting on Nitrox 32% rather than add in a new profile. I have 3 of the 5 profiles setup. I have had my Perdix in OC Tech mode since I bought it. Shearwater has done really good things to allow me to have what I want on the main screen.

@TT_Vert a dive buddy of mine just started using a Perdix but had been using oceanics for years.
At first he too thought the OC Tech mode was a litte frustrating but he saw how quckly I could setup his Perdix. IT was a case of knowing my Perdix and what the firmware has.

Now he if more familiar he loves how quickly he can get in OC TEC mode what he needs. He did need also to learn about Gradient Factors, Surf GF, GF99, and also understand when in Deco the TTS and what cealing was when that showed up. We did several deco dives together in Marldives in May and we use the same GF settings. So then we could compare dive profiles after uploading out dives.

Your issue really is not using your Perdix for five years, updating to new firmware and now there is a lot to learn. It takes time but your issue is not being familiar with the new firmware. A minute or two of setup time is just doing a pre dive check. Yeah and dont setup 1.6 when everyone else is on 1.4.

So deep dives are to 40m then? LOB should be able to mix 27% Nitrox which gives you a safe depth to 40m.