What is the maximum operating depth for EAN 34 with a partial pressure of oxygen limit of 1.40?

To determine the maximum operating depth for Enriched Air Nitrox (EAN) 34 with a partial pressure of oxygen limit of 1.40, one must understand how to calculate the maximum depth based on the gas mixture and the desired partial pressure of oxygen.

EAN 34 indicates that the mixture contains 34% oxygen. The remainder, 66%, is nitrogen. The partial pressure of oxygen (Ppo2) is the pressure exerted by the oxygen in the gas mixture at a specific depth. It can be calculated using the formula:

Ppo2 = (Fraction of oxygen) x (Total pressure)

For scuba diving, total pressure at a given depth can be expressed in atmospheres (atm) and is calculated as:

Total pressure = (Depth in feet / 33) + 1 atm (where 1 atm is the pressure at sea level)

To find the maximum depth where the partial pressure of oxygen does not exceed 1.40 atm, we set up the equation:

1.40 = 0.34 x (Depth/33 + 1)

Solving for depth involves rearranging the equation. First, isolate the total pressure:

(Depth / 33) + 1 = 1.40 /