SOME USEFUL FORMULAS

Equivalent Air Depth (EAD)

EAD = [(1 - fO2 / .79) X (D + 33)] - 33

For example - What is the EAD of EAN32 at 100 feet?

EAD = [1-.32 / .79) X (100 + 33)] - 33

EAD = .860 X 133 = 114

EAD = 114 - 33 = 81 feet

EAD = 81 feet

Maximum Operating Depth (MOD)

[(pO2/fO2) X 33] -33) = MOD

For example: What is the MOD of EAN32 if you want to use 1.4 ata as the max pO2?

1.4/.32 = 4.37 ata

(4.37 X 33) - 33 = 111 feet

Dalton's Triangle