Physics Caculations

Question 1

A diver suffering a DCI is given a total of 6 cycles of 30 minutes on BIB’s. The chamber is at 70 MSW. How much treatment mix is used?

Answer 1

28.8 m3

Question 2

A DDC with a FV of 16m3 is pressurised to 60 MSW. Temperature on arrival is 30 degrees C. Later the temperature falls to 26 degrees C. What is the new depth of the DDC?

Answer 2

59.2 meters

Question 3

Using a treatment mix at 137 msw with a ppo2 of 2.2, what is the O2 %?

Answer 3

14.9%

Question 4

Using a 425 MSW gauge, what does the reference marked on the gauge +- 0.25 of 1% equal as an acceptable error in when calibrated?

Answer 4

+- 1.06 MSW

Question 5

A DDC is at a depth of 380 FSW. The analyser at the surface shows the CO2 to be 420 ppm. What is the surface equivalent?

Answer 5

5254 PPM

Question 6

What is the metabolic consumption for 6 divers for 17 hours at 85 MSW?

Answer 6

3.06 m3

Question 7

What mix would be required to perform a dive to 250 FSW using a ppo2 of 1.3 ATA?

Answer 7

15%

Question 8

You are to use a 6% mix to establish a ppo2 of 400mb in a DDC.
To what depth would you pressurise with the 6%

Answer 8

21 MSW

Question 9

You require 195 bar of 8%.
Mixes available are 5 & 15%
How much 5% is required?

Answer 9

136.5 bar 5%

Question 10

Your company’s ppo2 during deco is .5 bar.
At what depth would the O2 % reach 21%

Answer 10

13.8 MSW

Question 11

You vent a chamber from 60 MSW to surface.
If the O2 was 5% at 60 metres, what is the O2 and ppO2 at surface?

Answer 11

50 mb \ 5%

Question 12

You are to pressurise a DDC from the surface to 75 MSW using 2% & 8%.
ppO2 required on bottom is 400 mb.
How deep will you pressurise the DDC on 8%?

Answer 12

6.66 MSW on 8%

Question 13

You have a DDC at 220 MSW.
The O2 is 2%.
If the DDC is vented to 130 MSW what is the ppo2 & O2 % at the new depth?

Answer 13

ppO2 = 280 mb \ O2 = 2%

Question 14

A colourmetric tube reading is taken in the bell and shows 0.6%.
Bell depth is 80 MSW.
How many PPM CO2 is showing on the surface analyser?

Answer 14

666 PPM

Question 15

A chamber is pressed from surface to 10 MSW using 6%.
What is the ppo2 in the chamber at 10 MSW?

Same chamber is pressurised from 10 MSW to 70 MSW using 4% HeO2.
What is the ppo2 at 70 MSW?

Same chamber is then pressurised from 70 to 120 MSW using 2.5% HeO2.
What will be the final ppO2 at 120 MSW and the O2%?

Answer 15

270 mb

510 mb

635 mb & 4.88% O2

Question 16

A DDC is pressurised from the surface to 210 MSW using 2% HeO2.
What is the He % at 210 MSW?

Answer 16

93.5%

Question 17

A 12 litre bailout is charged to 200 bar.
The dive is planned to 110 MSW.
How much umbilical can be deployed?

Answer 17

42 meters

Question 18

You have unlimited pure Helium & Oxygen, and want to make 195 bar of 6%.
How many bar of O2 is required?

Answer 18

11.7 bar O2

Question 19

If 300 psi of O2 is added to 1200 psi of 3%, what will be the final % of the mix?

Answer 19

22.4%

Question 20

Using the following mixes, using mix 2 as your base, how much 2% will be required to make 200 bar of 8%?

Mix 1 = 200 bar of 10%
Mix 2 = 50 bar of 3%
Mix 3 = 200 bar of 2%

Answer 20

7.5 bar 2%
(142.5 bar 10%)