Formulars Flashcards
Pressurising a chamber with rich and lean mix to get to a set PPO2
(PPO2 required- initial PPO2)-(depth x lean mix%) / (rich%-lean%)
P1T1= P2T2
Charles Law
Absolute depth(msw)
Depth(msw) + 10
Absolute depth(FSW)
Depth(FSW) + 33
Gauge Pressure(bar)
Depth(msw) / 10
Gauge Pressure(arm)
Depth(FSW) / 33
Absolute pressure
Gauge pressure + 1
Gauge Pressure
Absolute - 1
Depth(msw)
Gauge pressure x 10
Depth (FSW)
Gauge pressure x 33
Absolute depth (msw)
Absolute pressure (bar) x 10
Absolute depth (FSW)
Absolute pressure (atm) x 33
Gas consumption (met)
Absolute pressure (bar) x 35 liters/ minute
Gas consumption (imp)
Absolute pressure (ata) x 1.25 ft3/ minute
Free gas volume
Floodable volume x pressure
Free Gas Volume
(when FV is known)
Vol when full x Avail Press
————————————
Press when full
Time Available
Gas Available
—————————
Gas Consumption
Celsius to Fahrenheit
(1.8 x °C) + 32
Fahrenheit to Celsius
(°F - 32)
————-
1.8
Absolute temperature (°K)
°C +273
Absolute Temperature (°R)
°F + 460
Final Pressure
Initial Press abs x Final temperature (abs)
————————————-
Initial temperature (abs)
Final Depth
Initial depth x Final temperature (abs)
————————————
Initial Temperature (abs)
Partial Pressure
Abs Pressure x Decimal %
Partial Pressure (mb)
Absolute Depth (msw) x %
Gas Mixing
Pressure of Mix
( or use triangle)
Final Press x
(%final mix - % mix 2)
——————————
(% mix 1 - mix 2)
Depth of Rich Mix (msw)
(Ppo2 reqd (mb) - ppo2 present (mb) - (depth msw x % weak mix)
————————————
(% rich mix - % weak mix)
Depth of rich mix (FSW)
(3300x(ppo2 reqd(atm) - ppo2 present (atm)) - ( bottom depth x % weak mix)
————————————
(% rich mix - % weak mix)
PO2 increase (mb)
Depth increase (msw) x %
PO2 increase (atm)
Depth increase (FSW) x decimal %
————————————-
33
Free Gas Volume
Chamber Volume x Pressure added
10cm ( 0.1 msw) of pure O2 will increase the PPO2
10mb
1(FSW) pure O2 will increase PPO2
0.03atm
1 msw pure O2 will increase PPO2
0.1 bar
3 FSW pure O2 will increase PPO2
0.09atm
Oxygen used during decompression
(LN of the initial abs pressure) x PPO2(bar) x chamber volume
Sample tubes
True %
Scale Reading
———————-
Abs Pressure
Sample tubes
Partial Pressure ( bar or ata)
Scale Reading
———————-
100
Sample tubes
Partial Pressure (mb)
Scale reading x 10
Sample Tubes
SEP
= scale Reading
Buoyancy
Up thrust=
Volume of water displaced x density of water
Density of Freshwater
1kg/ liter
1 ton/ m3
10lbs/ imperial gallon
8.3lbs/ US gallon
62.5 lbs/ft3
Density of Sea Water
1.03 kg/ liter
1.03 ton/ m3
10.3 lbs/ Imperial gallon
8.6 lbs / US Gallon
64.38 lbs/ ft3
Diver Gas consumption
35 litre/minute
1.25 ft3/ minute
Diver Gas Consumption
( Recovery System)
5 litres/ minute
0.18 ft3/ minute
Divers Gas consumption from bail out or other supply source in an emergency
40 litres/ minute
1.5 ft3/ minute
Metabolic O2 consumption in chambers
- 0.72m3/ day or 0.5 L/min per diver.
- 25ft3/ day or 0.018ft3/ min per diver.
Soda Sorb usage
- 1kg absorbs 120 litres CO2.
- 1kg lasts on diver 4 hrs.
- 6 kg last one diver 24 hrs
