tremtech
Guest
nice spread sheet
Info The "Ultimate" wing lift calculator :)
- Thread starter selytch
- Start date
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jdelprete
Contributor
I see that you note the suit is 18# positive (wetsuit) yet up above the numbers show 16#. Is this a typo?
jdelprete
Contributor
nice table though, works well. I'm going from a single AL80 to doubles and was always wondering what my weight drop would be. It doesnt need to be exact but just getting close is a very nice start. Thanks...
PanamaMike
Registered
selytch:
When I sort the tanks by delta buoyancy, I get this:
AL80 4.8
ALN80 4.8
HP80 6
LP80 6
AL100 6.2
LP95 7
HP100 7.5
HP120 9
LP120 10
Delta buoyancy depends only on air capacity. I realize
that AL80 and LP80 don't have exactly the same volume, but
I'm surprised that the LP80 and HP80 have 25% more buoyancy
delta than the AL80. Also, the table says the Aluminum 100
holds about the same as a steel 80. You might want to include
fill pressures in your spread sheet.
Regards,
--Mike
Just ran across your spreadsheet, have three (helpful) comments:
1. It is buoyancy, not bouyancy.
2. The AL80/ALN80 "empty" weight is estimated at 500 psi still in the cylinder, but all the other cylinders assume 0 psi when empty. Best they are all assumed empty, for consistency.
3. The full/empty weights (buoyancies) are given in detail in http://www.huronscuba.com/equipment/scubaCylinderSpecification.html, in the last two columns.
- Mel
1. It is buoyancy, not bouyancy.
2. The AL80/ALN80 "empty" weight is estimated at 500 psi still in the cylinder, but all the other cylinders assume 0 psi when empty. Best they are all assumed empty, for consistency.
3. The full/empty weights (buoyancies) are given in detail in http://www.huronscuba.com/equipment/scubaCylinderSpecification.html, in the last two columns.
- Mel
tursiops:
Notes takes, thanks!
Sorry for misspelling.. http://admin.minus-mp3.com/buoyancy_calculator.xls
I added a worksheet with the cylinder specs so people could use it for reference.
Though I don't understand, why you say that AL80/ALN80 buoyancies are estimated at 500 psi...The numbers I put in there are pretty close to Luxfer 80/S80 specs.
PS. I am also starting a small divelog online
http://mydivelog.org
for tests - username "kostya" password "aaaa"
Visitors, let me know if you want to try one for yourself...
Sincerely,
Selytch.
dschulte
Contributor
I get an error when I try to go to your mydivelog.org
:monkeydan
:monkeydan
Homunculus
Contributor
nice excel sheet. the logbook works on my Mac (reffering to the previous post).
just a side note - the new faber cylinders (OMS) have different buoyancy numbers then those mentioned in your excel file. i belive the values you have are for older models.
thank you
P.S.
does anyone know how to figure out the wetsuit (neoprene) buoyancy??? is there a formula that anyone is aware of? please!!!
just a side note - the new faber cylinders (OMS) have different buoyancy numbers then those mentioned in your excel file. i belive the values you have are for older models.
thank you
P.S.
does anyone know how to figure out the wetsuit (neoprene) buoyancy??? is there a formula that anyone is aware of? please!!!
Rainer
Contributor
Mikhail Frenkel:
You must mean the compressed buoyancy characteristics, correct? Pre-compression you just check how much weight to sink you. Post-compression is much harder. I don't have a good means of measuring this. Nor do manufacturers seem to know these numbers (at least the few I've asked).
Hi Mike,
You are right, Delta buoyancy depends only on air capacity (well actually air consumed). It doesn't look like the manufacturers data is consistant.
Hi Constantin,
Probably the best data to start from would be manufactures specified FULL buoyancy and calculate change in buoyancy from .0807 x [cu. ft. air expected to use]. IMHO, calculating weight loss from consumed air is more accurate than relying on manufacturers data for buoyancy of an empty tank.
You could add a field "Air Capacity, cu. ft. used" and change the "Tank Empty" field to a calculated field.
For change in buoyancy when going from salt water to fresh water, take your entire weight (diver plus gear plus weights) and multiply by 0.028125. That will be the amount of lead you have to REMOVE to achieve the same buoyancy.
You could add an entry field for "Divers total rigged weight" and multiply that field by .028125 for a calculated field marked "amount of lead to remove for fresh water". The difference in BC lift is insignificant between salt and fresh water.
If I weigh myself fully rigged for salt water, I weigh 214 lb. including my 8 pound weight belt. In fresh water, the same rig requires 2 - 1 pound bullet weights for the same buoyancy. 214 pounds times .028125 = 6.01875 pounds. Not too far from the 6 pounds that I removed from the belt.
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