Various Flashcards
1 Litre of seawater weighs ?
1.03kg
Litre of fresh water
1kg
1 Cubic foot seawater weighs?
64.38lbs
Cubic foot of fresh water
62.5lbs
Upthrust =
Volume x density
Density=
Mass/Volume
Atmospheric imperial ATA=
14.7psi 760mm of mercury mmHg
Atmospheric metric bar abs=
14.5psi 750mmHg mercury
Barometric pressure is?
Essentially same as atmospheric, but varying with weather and expressed in terms height column mercury
Gauge pressure is?
Starts at Zero when read on surface at atmospheric pressure
Absolute pressure is?
Total pressure exerted , gauge pressure plus atmospheric
Seawater m3 density
1030kg/m3
Fresh water density m3
1000kg/m3
3 types of Heat transfer
Conduction, main cause heat loss.
Convection
Radiation
Water conducts heat
24 more times more than air
Sound travels in water….
4 times faster than in air
Fahrenheit to absolute temp
Rankin = F + 460
Celsius to absolute temperature
Kelvin = Celsius + 273
Fahrenheit to C =
F -32/1.8
Celsius to Fahrenheit
C x 1.8 + 32
Normal diver consumption rate
35LPM/ 1.25ft3
Emergency consumption rate
40LPM/1.5ft3 min
Formula for finding absolute pressure metric measurements
Depth MSW/10+1
Formula for finding FGV WHEN FV is unknown
Vol full X Avail press
press full
FGV WHEN FV Known
FGV = PRESSURE X VOLUME
Litres to one ft3
28.32 litres
Imperial ton lbs?
2240lbs
1 US TON LBS?
2000lbs
1fsw is how many PSI?
0.445psi
FSW/? = MSW
3.281
Reclaim gas usage
5 LPM OR 0.18ft3/min
Chamber BIBS CONSUMPTION in LPM AND ft3/min?
20 LPM OR 0.7ft3/min
Metabolic O2 consumption metric imca D050
0.5LPM, 30 LPH, 720per day
0.72m3
Metabolic 02 consumption imperial
0.018ft3/min 25ft3/day per diver
Cubic feet in one cubic metre?
35.32 cubic feet
PPM TO %
Divide by 10’000
% to PPM
Multiply by 10’000
PPM TO PP
Divide by 1000’000
PP to PPM
X 1’000’000
% to PP
% divided by 100
PP TO %
PP X 100
Partial Pressure(mb) =
Absolute depth (MSW) x %
EAD FORMULA FPS
N2% x ABS DEPTH/79-33
EAD FORMULA METRIC
N2% X ABS DEPTH/79-10
FINAL DEPTH =
Max co2 ppm?
5000ppm Co2
0.5%
5mb
0.005 bar
General gas law
P1xV1 = P2xV2
T1. T2
1kg Soda lime absorbs ?
120 Litres co2
1kg soda lime last a diver how long?
1kg 4hours
Alternative formula for PP in mb?
Pp(mb) = ABS depth X %, not decimal %
Adding o2 to the chamber ppo2 increases by:
10cm, increase ppo2 by 10mb.
1 msw by 0.1bar
1 fsw increases by 0.03atm
3 fsw by 0.09atm
OXYGEN USED DURING DECO FORMULA=
(Ln of initial pressure)X ppo2(bar) x chamber volume.
Page 28/29 Imca d 022
Fleet angle should not exceed?
1.5 degrees
Fleet is half length of the drum, distance moved from centre to edge of drum.
How many turns of wire should remain in drum?
5 turns, pressure lubricated 6 monthly or replaced every 2 years.
Man riding winches should have?
2 independent brakes , subject to 6 monthly and annual load tests , plus ndt of welds.
Drum should not be overloaded with cable……
2.5 times the diameter of the wire between the outside of top layer and edge of the drum flange.
Convert litres to ft3?
Multiply by?
0.035 ft
BIBS CONSUMPTION
20LPM, 0.7ft3 min
28.8m3 day / 1017ft3 day
Heliox environment minimum oxygen % for combustion is?
6%
Co2 tube in bell at 400 fsw scale reading 1.4%
True % co2, pCo2, SEP?
True % = 0.107%
Pco2 = 0.014
SEP 1.4%
Beaufort windscale gentle breeze?
FORCE 3
Beaufort strong breeze? Force and knots
Force 6, 22-27knots
Beaufort gale?
Force 8
Transponder and transducer locations?
Transponder on the bottom.
Transducer on vessel.
Ft3 to m3?
X 0.28