Set point change over

***Decodiver*** · 22nd June 2005, 17:56

I used to change on the bottom 60m or 120m or whatever, I now change at 20m.

I found if you change your setpoint once at depth the Inspiration would often overshoot, I got into the habit of changing earlier seeing as it is always me who ties in and dragging a grapnel whilst dealing with a high O2 drill is a PITA.

So change at 20m now and have no problems at all, Inspiration or Meg.

Cheers,

Dave Cooper.

ROB DAVIE · 22nd June 2005, 18:20

Folks,

I use a mix of Nigel's format and Cedric's, in that I:

(1) because of my occupation, I equalize extremely rapidly and automatically, so I descend like a home-sick angel in reverse (after initial bubble, equip, and buddy checks)

(2) pause at target depth, reset set point, re-check equip, a few deep breaths to relax

et voila, off we go to enjoy the dive!

Rob

Pierre Farrugia · 22nd June 2005, 22:30

When you say check eqiupment what you eactly do ?

**wedivebc** · 23rd June 2005, 02:05

Quote: (Originally Posted by Beanie)

I was taught the 2, 5, 10
2 bubble check, equipment check etc
5 equipment check etc
10 set point switch (on the fly)

Did this on Sunday on the way to 50m my PO2 Spiked to 1.4-1.5 and settled quickly on the bottom, so works pretty well.

What he said.....

RebreatherDave · 23rd June 2005, 07:29

The Vision electronics changes the setpoint based upon depth for you?

I didn't know that...now I am REALLY going to enjoy my toy in the next 10 days....

Pierre Farrugia · 23rd June 2005, 07:36

If this is a reply to my post...I didn't understand anything! Why people reply in such a manner I don't understand.

Quote: (Originally Posted by wedivebc)

What he said.....

Drmike · 23rd June 2005, 07:56

My unit auto switches at around 4m.

A momentary spike in O2 on descent will not hurt. Unless you are running a dil with too high an FO2 content the dil will bring the spike under control quickly as you descend and the ADV injects.

On descents I like to spike the O2 over setpoint anyway as it proves (at the start of the dive) that the sensors are not current limited. It also proves all the ppo2 sensing system, LEDs in the HUD including the high ppo2 alarm is working correctly.

It doesn't make sense to me to choose an arbitrary depth to manually switch. The switch depth depends on the specifics of each dive and dil being used.

If there is a strong current for eg. on a deep dive and the downline is almost horizontal it can take a long while to descend and you will be ongassing. In this case you would be better off switching well before you get to target depth.

On dives where a rapid descent is possible and a high FO2 dil is being used there may be no need to switch at all untill the descent phase is over. Conversely if a low FO2 dil is being used, even on a rapid descent dive, switching at 4m may be fine.

So best bet if manual switching would be to check your handsets and decide for yourself when to switch based on the specifics of the particular dive.

***jradomski*** · 23rd June 2005, 09:32

Quote: (Originally Posted by Drmike)

My unit auto switches at around 4m.

A momentary spike in O2 on descent will not hurt. Unless you are running a dil with too high an FO2 content the dil will bring the spike under control quickly as you descend and the ADV injects.

On descents I like to spike the O2 over setpoint anyway as it proves (at the start of the dive) that the sensors are not current limited. It also proves all the ppo2 sensing system, LEDs in the HUD including the high ppo2 alarm is working correctly.

It doesn't make sense to me to choose an arbitrary depth to manually switch. The switch depth depends on the specifics of each dive and dil being used.

If there is a strong current for eg. on a deep dive and the downline is almost horizontal it can take a long while to descend and you will be ongassing. In this case you would be better off switching well before you get to target depth.

On dives where a rapid descent is possible and a high FO2 dil is being used there may be no need to switch at all untill the descent phase is over. Conversely if a low FO2 dil is being used, even on a rapid descent dive, switching at 4m may be fine.

So best bet if manual switching would be to check your handsets and decide for yourself when to switch based on the specifics of the particular dive.

I agree On dives where I am going to go deep, I want to descent as quickly as possible and high setpoint impedes my descent especially once you start approaching your target depth.. even on a low setpoint I know I usually keep the po2 between 1.4 and 1.5 without oxygen ever being added (unless I am using a REALLY hypoxic mix)..

With the HH I have multiple setpoints, I may raise it to around a 1.0 (not my bottom sp) but insures a high po2 if I get delayed a bit.. on the deep stuff small differences in sp really dont make a big difference on the bottom phase when deep, it makes a big difference on deco especially the shallower you get..

The fastest descent I can confortably do is about 60m per minute (after the first 10m)..

pchanning · 23rd June 2005, 13:20

Quote: (Originally Posted by jradomski)

I agree On dives where I am going to go deep, I want to descent as quickly as possible... the fastest descent I can confortably do is about 60m per minute (after the first 10m)..

"60m per minute" thats impressive. The vis must be great, sometimes I tend to bump into the wreck before I see it..!!

Still, I geuss you dont have to tie-in if you carry the shot with you.

***jradomski*** · 23rd June 2005, 16:17

Quote: (Originally Posted by Mr. Greekbird)

"60m per minute" thats impressive. The vis must be great, sometimes I tend to bump into the wreck before I see it..!!

Still, I geuss you dont have to tie-in if you carry the shot with you.

I definately only do this when there is good Viz and bottom time really counts... Having a hard surface stop my descent wouldn't be a pleasant experience...

22nd June 2005, 17:56	#11 (permalink)
*Decodiver* Administrator Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jan 2005 Location: Geneva Posts: 2,190	I used to change on the bottom 60m or 120m or whatever, I now change at 20m. I found if you change your setpoint once at depth the Inspiration would often overshoot, I got into the habit of changing earlier seeing as it is always me who ties in and dragging a grapnel whilst dealing with a high O2 drill is a PITA. So change at 20m now and have no problems at all, Inspiration or Meg. Cheers, Dave Cooper. __________________ CCR/OC Trimix Instructor Trainer CCR Training to Mixed Gas in Switzerland, France, UK & Germany on Megalodon/COPIS-Megalodon/KISS/Sport KISS/Ouroboros/rEvo/Inspiration/Evolution/Sentinel www.zerogravitydiving.com Rebreather World Terms & Conditions
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22nd June 2005, 18:20	#12 (permalink)
ROB DAVIE Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: HOUSTON, REPUBLIC OF TEJAS Posts: 1,120	Set point change-over Folks, I use a mix of Nigel's format and Cedric's, in that I: (1) because of my occupation, I equalize extremely rapidly and automatically, so I descend like a home-sick angel in reverse (after initial bubble, equip, and buddy checks) (2) pause at target depth, reset set point, re-check equip, a few deep breaths to relax et voila, off we go to enjoy the dive! Rob __________________ "CC Rebreathers will become a viable part of tech diving WHEN PIGS FLY!!"--GI3
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22nd June 2005, 22:30	#13 (permalink)
Pierre Farrugia Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Malta Posts: 636	When you say check eqiupment what you eactly do ? __________________ Pierre Farrugia My wife told me " If you don't quit diving I'm going to leave you" My reply " God, I'll miss you" www.atlam.org www.divemed.com
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23rd June 2005, 02:05	#14 (permalink)
wedivebc Dave Tomblin Current Rebreather/s: Megalodon Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Other CCR Join Date: Feb 2005 Location: Vancouver Island BC Canada Posts: 1,493	Quote: (Originally Posted by Beanie) I was taught the 2, 5, 10 2 bubble check, equipment check etc 5 equipment check etc 10 set point switch (on the fly) Did this on Sunday on the way to 50m my PO2 Spiked to 1.4-1.5 and settled quickly on the bottom, so works pretty well. What he said..... __________________ Cheers, Dave.... Man is the only animal burdened with the knowledge he will eventually die
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23rd June 2005, 07:29	#15 (permalink)
RebreatherDave Maximum **** Current Rebreather/s: Inspiration Classic Other Rebreather/s:** Join Date: May 2005 Location: L.A., where the debris meets the sea Posts: 226	The Vision electronics changes the setpoint based upon depth for you? I didn't know that...now I am REALLY going to enjoy my toy in the next 10 days....
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23rd June 2005, 07:36	#16 (permalink)
Pierre Farrugia Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Malta Posts: 636	If this is a reply to my post...I didn't understand anything! Why people reply in such a manner I don't understand. Quote: (Originally Posted by wedivebc) What he said..... __________________ Pierre Farrugia My wife told me " If you don't quit diving I'm going to leave you" My reply " God, I'll miss you" www.atlam.org www.divemed.com
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23rd June 2005, 07:56	#17 (permalink)
Drmike RBW Member Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,340	My unit auto switches at around 4m. A momentary spike in O2 on descent will not hurt. Unless you are running a dil with too high an FO2 content the dil will bring the spike under control quickly as you descend and the ADV injects. On descents I like to spike the O2 over setpoint anyway as it proves (at the start of the dive) that the sensors are not current limited. It also proves all the ppo2 sensing system, LEDs in the HUD including the high ppo2 alarm is working correctly. It doesn't make sense to me to choose an arbitrary depth to manually switch. The switch depth depends on the specifics of each dive and dil being used. If there is a strong current for eg. on a deep dive and the downline is almost horizontal it can take a long while to descend and you will be ongassing. In this case you would be better off switching well before you get to target depth. On dives where a rapid descent is possible and a high FO2 dil is being used there may be no need to switch at all untill the descent phase is over. Conversely if a low FO2 dil is being used, even on a rapid descent dive, switching at 4m may be fine. So best bet if manual switching would be to check your handsets and decide for yourself when to switch based on the specifics of the particular dive.
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23rd June 2005, 09:32	#18 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,096	Quote: (Originally Posted by Drmike) My unit auto switches at around 4m. A momentary spike in O2 on descent will not hurt. Unless you are running a dil with too high an FO2 content the dil will bring the spike under control quickly as you descend and the ADV injects. On descents I like to spike the O2 over setpoint anyway as it proves (at the start of the dive) that the sensors are not current limited. It also proves all the ppo2 sensing system, LEDs in the HUD including the high ppo2 alarm is working correctly. It doesn't make sense to me to choose an arbitrary depth to manually switch. The switch depth depends on the specifics of each dive and dil being used. If there is a strong current for eg. on a deep dive and the downline is almost horizontal it can take a long while to descend and you will be ongassing. In this case you would be better off switching well before you get to target depth. On dives where a rapid descent is possible and a high FO2 dil is being used there may be no need to switch at all untill the descent phase is over. Conversely if a low FO2 dil is being used, even on a rapid descent dive, switching at 4m may be fine. So best bet if manual switching would be to check your handsets and decide for yourself when to switch based on the specifics of the particular dive. I agree On dives where I am going to go deep, I want to descent as quickly as possible and high setpoint impedes my descent especially once you start approaching your target depth.. even on a low setpoint I know I usually keep the po2 between 1.4 and 1.5 without oxygen ever being added (unless I am using a REALLY hypoxic mix).. With the HH I have multiple setpoints, I may raise it to around a 1.0 (not my bottom sp) but insures a high po2 if I get delayed a bit.. on the deep stuff small differences in sp really dont make a big difference on the bottom phase when deep, it makes a big difference on deco especially the shallower you get.. The fastest descent I can confortably do is about 60m per minute (after the first 10m).. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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23rd June 2005, 13:20	#19 (permalink)
pchanning PFO free :) Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: fixed! Posts: 454	Quote: (Originally Posted by jradomski) I agree On dives where I am going to go deep, I want to descent as quickly as possible... the fastest descent I can confortably do is about 60m per minute (after the first 10m).. "60m per minute" thats impressive. The vis must be great, sometimes I tend to bump into the wreck before I see it..!! Still, I geuss you dont have to tie-in if you carry the shot with you.
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23rd June 2005, 16:17	#20 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,096	Quote: (Originally Posted by Mr. Greekbird) "60m per minute" thats impressive. The vis must be great, sometimes I tend to bump into the wreck before I see it..!! Still, I geuss you dont have to tie-in if you carry the shot with you. I definately only do this when there is good Viz and bottom time really counts... Having a hard surface stop my descent wouldn't be a pleasant experience... __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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