-
Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:
- Join over 44,280+ fellow diving enthusiasts from around the world on this forum
- Participate in and browse from over 516,210+ posts.
- Communicate privately with other divers from around the world.
- Post your own photos or view from 7,441+ user submitted images.
- All this and much more...
You can gain access to all this absolutely free when you register for an account, so sign up today!
Fill ear with fluid?
- Thread startersumpa
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
Although the question was directed at Eric, I will guess that the figured come from the following:
[Max Depth for acheiving a full mouthfill] + ([Additional equalization depth acheived by using the air in your mouth to equalize]*([Volume of TOTAL equalization space]/[Amount of that volume that can be offset by filling with water]))
I assume that
[Max depth for acheiving a full mouthfill] = [10 meters] * (([Volume of air inhaled]/[Reserve Volume]) - 1)
which depends entirely on the person.
All of the numbers after that will be based on the first number because that is the point at which the rate of volume compression becomes relevant.
But assuming that you acheived your last mouthfill at [40 meters] then by the time you got to [90 meters] you would need to double the amount of air in your equalization cavities to maintain the same degree of comfort. So assuming the air in your equalization cavaties was at the same pressure as the air in your mouth when you do the mouth fill at [40 meters] the amount of extra depth can be calculated by comparing the volume of air in your mouth with the volume of your equalization cavities at [40 meters] according to the follwing formula.
m =eq ; [50 m] 1
m = 2eq; [150m] 3
m = 3eq; [350m] 7
m = 4eq; [750m] 15
[additional depth] = ([Depth of last mouthfill] + [10 meters]) * ((2 ^ ([vol of air in mouth]/[vol of eq cavities])) - 1)
[Max Depth for acheiving a full mouthfill] + ([Additional equalization depth acheived by using the air in your mouth to equalize]*([Volume of TOTAL equalization space]/[Amount of that volume that can be offset by filling with water]))
I assume that
[Max depth for acheiving a full mouthfill] = [10 meters] * (([Volume of air inhaled]/[Reserve Volume]) - 1)
which depends entirely on the person.
All of the numbers after that will be based on the first number because that is the point at which the rate of volume compression becomes relevant.
But assuming that you acheived your last mouthfill at [40 meters] then by the time you got to [90 meters] you would need to double the amount of air in your equalization cavities to maintain the same degree of comfort. So assuming the air in your equalization cavaties was at the same pressure as the air in your mouth when you do the mouth fill at [40 meters] the amount of extra depth can be calculated by comparing the volume of air in your mouth with the volume of your equalization cavities at [40 meters] according to the follwing formula.
m =eq ; [50 m] 1
m = 2eq; [150m] 3
m = 3eq; [350m] 7
m = 4eq; [750m] 15
[additional depth] = ([Depth of last mouthfill] + [10 meters]) * ((2 ^ ([vol of air in mouth]/[vol of eq cavities])) - 1)
Eric's a sofware engineer. Check out http://www.ericfattah.com.
David's a system's engineer or something so a bit of a geek as well.
David's a system's engineer or something so a bit of a geek as well.
[Max depth for acheiving a full mouthfill] = [10 meters] * (([Volume of air inhaled]/[Reserve Volume]) - 1) "
I've been working on this for quite a while. Let me throw out some numbers and some thinking. I've done some 'reverse' measuring and still can't juggle things to work the way I would like. Not to be disagreeable, but first let me redo your formula.....
[Max depth for acheiving a full mouthfill] = [10 meters] * (([Volume of air inhaled + Reserve volume + full mask volume + sinus and nasal cavity volume/[Reserve Volume + squeezed mask volume + sinus and nasal cavity volume]) - 1). It does make a difference and even this formula leaves out a few important variables (blood shift and air loss).
In my case, I leave the surface with about 8L total air which squeezes to 1.6 at 40M (1.36 lungs, .09 mask, 0.1 mouth and .05 cavities) and 1L at 70M (0.88 lungs, .07 mask and .05 cavities). Normally things don't work perfectly and I end up 5M short. The mouthfill gives me 8/5 or 1.6 times residual in atmospheres.
The problem with these figures becomes apparent when I do a negative. If I lie on the surface, fill my mouth and empty my lungs (1.36, .09, 0.1 and .05), it's easy to drop to 14M (2.4 residual atm.). Since my lungs are sealed off, they shrink to 0.55 and .24L becomes 0.1, which isn't enough for the mask and cavities. When I tried without a mask, the air went to my lungs instead of the sinuses, at 16 or 17M.
Does anyone understand this stuff well enough to explain what is happening.
Aloha
Bill
I've been working on this for quite a while. Let me throw out some numbers and some thinking. I've done some 'reverse' measuring and still can't juggle things to work the way I would like. Not to be disagreeable, but first let me redo your formula.....
[Max depth for acheiving a full mouthfill] = [10 meters] * (([Volume of air inhaled + Reserve volume + full mask volume + sinus and nasal cavity volume/[Reserve Volume + squeezed mask volume + sinus and nasal cavity volume]) - 1). It does make a difference and even this formula leaves out a few important variables (blood shift and air loss).
In my case, I leave the surface with about 8L total air which squeezes to 1.6 at 40M (1.36 lungs, .09 mask, 0.1 mouth and .05 cavities) and 1L at 70M (0.88 lungs, .07 mask and .05 cavities). Normally things don't work perfectly and I end up 5M short. The mouthfill gives me 8/5 or 1.6 times residual in atmospheres.
The problem with these figures becomes apparent when I do a negative. If I lie on the surface, fill my mouth and empty my lungs (1.36, .09, 0.1 and .05), it's easy to drop to 14M (2.4 residual atm.). Since my lungs are sealed off, they shrink to 0.55 and .24L becomes 0.1, which isn't enough for the mask and cavities. When I tried without a mask, the air went to my lungs instead of the sinuses, at 16 or 17M.
Does anyone understand this stuff well enough to explain what is happening.
Aloha
Bill
Last edited:
Yeah I didn't take any of those figures into account in the first equation. The corrected equation would be as follows...
[Max depth for acheiving a full mouthfill] = [10 meters] * (([Volume of air inhaled] - [Volume of equalization space] * (([Max depth for acheiving a full mouthfill] + [10 meters]) / [10 meters]) + 1) - [Volume of mouthfill] * (([Max depth for acheiving a full mouthfill] + [10 meters]) / [10 meters])/([Reserve Volume]))
Okay so this is what that is saying...
Figure out how deep you can go if you didn't have to equalize anything. Subtract the amount of the volume you needed to equalize which is a function of how deep you are. Subtract the amount that you need for the mouthfill, which is also a function of how deep you are.
I am sure that the primary variable can be isolated., but I am presently too lazy to do it.
I assume that lung swell isn't relevant because once you get far enough down for that to occur, I doubt you could do a mouthfill anyway. Am I mistaken? That would be really neat if you could mouthfill after you hit reserve. Wouldn't that mean that you had inaccurately measured you reserve?
And as far as Bill's final question, it sounds like you accidentally opened your glottis, and didn't actually hit reserve until after you left the surface.
[Max depth for acheiving a full mouthfill] = [10 meters] * (([Volume of air inhaled] - [Volume of equalization space] * (([Max depth for acheiving a full mouthfill] + [10 meters]) / [10 meters]) + 1) - [Volume of mouthfill] * (([Max depth for acheiving a full mouthfill] + [10 meters]) / [10 meters])/([Reserve Volume]))
Okay so this is what that is saying...
Figure out how deep you can go if you didn't have to equalize anything. Subtract the amount of the volume you needed to equalize which is a function of how deep you are. Subtract the amount that you need for the mouthfill, which is also a function of how deep you are.
I am sure that the primary variable can be isolated., but I am presently too lazy to do it.
I assume that lung swell isn't relevant because once you get far enough down for that to occur, I doubt you could do a mouthfill anyway. Am I mistaken? That would be really neat if you could mouthfill after you hit reserve. Wouldn't that mean that you had inaccurately measured you reserve?
And as far as Bill's final question, it sounds like you accidentally opened your glottis, and didn't actually hit reserve until after you left the surface.
Yeah I didn't take any of those figures into account in the first equation. The corrected equation would be as follows...
[Max depth for acheiving a full mouthfill] = [10 meters] * (([Volume of air inhaled] - [Volume of equalization space] * (([Max depth for acheiving a full mouthfill] + [10 meters]) / [10 meters]) + 1) - [Volume of mouthfill] * (([Max depth for acheiving a full mouthfill] + [10 meters]) / [10 meters])/([Reserve Volume]))
Okay so this is what that is saying...
Figure out how deep you can go if you didn't have to equalize anything. Subtract the amount of the volume you needed to equalize which is a function of how deep you are. Subtract the amount that you need for the mouthfill, which is also a function of how deep you are.
I am sure that the primary variable can be isolated., but I am presently too lazy to do it.
I assume that lung swell isn't relevant because once you get far enough down for that to occur, I doubt you could do a mouthfill anyway. Am I mistaken? That would be really neat if you could mouthfill after you hit reserve. Wouldn't that mean that you had inaccurately measured you reserve?
And as far as Bill's final question, it sounds like you accidentally opened your glottis, and didn't actually hit reserve until after you left the surface.
[Max depth for acheiving a full mouthfill] = [10 meters] * (([Volume of air inhaled] - [Volume of equalization space] * (([Max depth for acheiving a full mouthfill] + [10 meters]) / [10 meters]) + 1) - [Volume of mouthfill] * (([Max depth for acheiving a full mouthfill] + [10 meters]) / [10 meters])/([Reserve Volume]))
Okay so this is what that is saying...
Figure out how deep you can go if you didn't have to equalize anything. Subtract the amount of the volume you needed to equalize which is a function of how deep you are. Subtract the amount that you need for the mouthfill, which is also a function of how deep you are.
I am sure that the primary variable can be isolated., but I am presently too lazy to do it.
I assume that lung swell isn't relevant because once you get far enough down for that to occur, I doubt you could do a mouthfill anyway. Am I mistaken? That would be really neat if you could mouthfill after you hit reserve. Wouldn't that mean that you had inaccurately measured you reserve?
And as far as Bill's final question, it sounds like you accidentally opened your glottis, and didn't actually hit reserve until after you left the surface.
I simplified and arrived at this...
[10 meters]
* ([Volume of air inhaled] - 2 * [Volume of equalization space] - [Volume of mouthfill])
/ ([Reserve Volume] + [Volume of equalization space] + [Volume of mouthfill])
[10 meters]
* ([Volume of air inhaled] - 2 * [Volume of equalization space] - [Volume of mouthfill])
/ ([Reserve Volume] + [Volume of equalization space] + [Volume of mouthfill])
Calculating your max equalizing depth is very simple....
1. Calculate your max depth on a mouthfill:
- Fill your mouth at the surface, close your epiglottis
- Descend as far as possible until you can't equalize
- Record this as D1
- Then, on a deep dive, find the max depth that you can do the mouthfill, and still have a FULL fill, like the fill you had at the surface; call this depth D2
D1 and D2, combined, determine your max equalizing depth with the mouthfill:
Max depth = (((0.1*D1)+1)*(0.1*D2+1) - 1) * 10
Example, for me,
D1 = 30.6m
D2 = 40m if I turn horizontal
Max depth = (((0.1*30.6m)+1)*(0.1*40m+1) - 1 ) * 10 = 193m
2. Calculate your max depth on a watersuck
DO NOT ATTEMPT THIS!!!
- Fill your mouth at the surface, close your epiglottis, pour the saline into your mouth
- Descend as far as possible until you can't equalize
- Record this as D1
- Then, on a deep dive (with a SPOTTER AT DEPTH), fill your mouth with the saline at the surface, then descend, and find the max depth that you can do the mouthfill, and still have a FULL fill, like the fill you had at the surface; call this depth D2
D1 and D2, combined, determine your max equalizing depth with the watersuck.
Max depth = (((0.1*D1)+1)*(0.1*D2+1) - 1) * 10
1. Calculate your max depth on a mouthfill:
- Fill your mouth at the surface, close your epiglottis
- Descend as far as possible until you can't equalize
- Record this as D1
- Then, on a deep dive, find the max depth that you can do the mouthfill, and still have a FULL fill, like the fill you had at the surface; call this depth D2
D1 and D2, combined, determine your max equalizing depth with the mouthfill:
Max depth = (((0.1*D1)+1)*(0.1*D2+1) - 1) * 10
Example, for me,
D1 = 30.6m
D2 = 40m if I turn horizontal
Max depth = (((0.1*30.6m)+1)*(0.1*40m+1) - 1 ) * 10 = 193m
2. Calculate your max depth on a watersuck
DO NOT ATTEMPT THIS!!!
- Fill your mouth at the surface, close your epiglottis, pour the saline into your mouth
- Descend as far as possible until you can't equalize
- Record this as D1
- Then, on a deep dive (with a SPOTTER AT DEPTH), fill your mouth with the saline at the surface, then descend, and find the max depth that you can do the mouthfill, and still have a FULL fill, like the fill you had at the surface; call this depth D2
D1 and D2, combined, determine your max equalizing depth with the watersuck.
Max depth = (((0.1*D1)+1)*(0.1*D2+1) - 1) * 10
To clarify my last post, I'll share the logic:
- If you can make it to 20m, on one mouthfill from the surface (1 atm), then you reached 3atm; so you filled your mouth at 1atm, and reached 3atm when you ran out of air to equalize. So, at whatever depth you fill your mouth, you will reach three times that pressure
- Now, if you filled your mouth at depth, say at 30m, then you are doing the fill at 4atm. But, you know that you can reach triple the pressure at which you filled, or 3*4atm = 12atm, = 110m
This formula/logic has been tested by various people and has proven accurate so far. The only error in the formula is the non-ideal gas nature of air at depth, which means that your true max will be slightly higher than the formula predicts. You could use the Van der Waals equation for non-ideal gases to find a more accurate formula.
- If you can make it to 20m, on one mouthfill from the surface (1 atm), then you reached 3atm; so you filled your mouth at 1atm, and reached 3atm when you ran out of air to equalize. So, at whatever depth you fill your mouth, you will reach three times that pressure
- Now, if you filled your mouth at depth, say at 30m, then you are doing the fill at 4atm. But, you know that you can reach triple the pressure at which you filled, or 3*4atm = 12atm, = 110m
This formula/logic has been tested by various people and has proven accurate so far. The only error in the formula is the non-ideal gas nature of air at depth, which means that your true max will be slightly higher than the formula predicts. You could use the Van der Waals equation for non-ideal gases to find a more accurate formula.
D1 = (2 ^ ([vol of air in mouth]/[vol of eq cavities]) - 1) * [10 meters]
It works out to be the same when you add
[additional depth] = ([Depth of last mouthfill] + [10 meters]) * ((2 ^ ([vol of air in mouth]/[vol of eq cavities])) - 1)
[additional depth] + [Depth of last mouthfill] = [total depth]
and simplify
([Depth of last Mouthfill] + [10 meters])
* (2 ^ ([vol of air in mouth]/[vol of eq cavities]))
- [10 meters]
=
((D2 + [10 meters]) * ((D1 / [10 meters]) + 1)) - [10 meters]
It works out to be the same when you add
[additional depth] = ([Depth of last mouthfill] + [10 meters]) * ((2 ^ ([vol of air in mouth]/[vol of eq cavities])) - 1)
[additional depth] + [Depth of last mouthfill] = [total depth]
and simplify
([Depth of last Mouthfill] + [10 meters])
* (2 ^ ([vol of air in mouth]/[vol of eq cavities]))
- [10 meters]
=
((D2 + [10 meters]) * ((D1 / [10 meters]) + 1)) - [10 meters]
What are some average numbers for D1 and D2. Based on this, and in finer detail, at the risk of sacrificing relevancy, what are some average numbers for [vol of mouth fill], [vol of eq space], [max lung volume] and [reserve volume]. if those numbers are known, experimental determination of d1 and d2 are unecessary as the other 4 numbers are what really 'makes or breaks' a free diver once he or she hits the limits.
Of these 4 variables are any of them controllable other than [max lung volume]?
Of these 4 variables are any of them controllable other than [max lung volume]?
Jason,
Unfortunately, experimental determination of D1 and D2 seem to be the only reliable method. For example:
- Mouthfill volume varies dramatically with skill (head position, timing of epiglottis closure, jaw position etc..)
- Body position to fully exhale (and fill the mouth) is very strange and requires skill; this is a learned technique which dramatically affects the max mouthfill depth D2
- Residual volume varies with blood shift, hard to calculate at depth
- Lung volume varies from day to day with stretching/flexibility, packing efficiency/body position etc...
That's why I find it far simpler to quickly determine D1 and D2 in a single dive session.
To put my example in perspective, in my early days (Feb 1999):
D1 = 11m
D2 = 25m
But with lots of practice,
D1 = 30.6m
D2 = 40m
Eric Fattah
BC, Canada
Unfortunately, experimental determination of D1 and D2 seem to be the only reliable method. For example:
- Mouthfill volume varies dramatically with skill (head position, timing of epiglottis closure, jaw position etc..)
- Body position to fully exhale (and fill the mouth) is very strange and requires skill; this is a learned technique which dramatically affects the max mouthfill depth D2
- Residual volume varies with blood shift, hard to calculate at depth
- Lung volume varies from day to day with stretching/flexibility, packing efficiency/body position etc...
That's why I find it far simpler to quickly determine D1 and D2 in a single dive session.
To put my example in perspective, in my early days (Feb 1999):
D1 = 11m
D2 = 25m
But with lots of practice,
D1 = 30.6m
D2 = 40m
Eric Fattah
BC, Canada
Eric,
30,6 is VERY deep on one mouthfill.
I assume your last "pop" of your ears is somewhere around 20-25 or are 30,6 the depth where you can "pop" the ears?
Maybe you have a constant pressure wtih your tongue instead of "popping" the ears....
30,6 is VERY deep on one mouthfill.
I assume your last "pop" of your ears is somewhere around 20-25 or are 30,6 the depth where you can "pop" the ears?
Maybe you have a constant pressure wtih your tongue instead of "popping" the ears....
Last edited: