What does PPO2 stand for in Nitrox diving?

PPO2 stands for Partial Pressure of Oxygen. In the context of diving and Nitrox use, it refers to the pressure exerted by oxygen in a gas mixture at a given depth. This concept is crucial for divers because the partial pressure of oxygen directly affects the amount of oxygen available for breathing and its physiological effects on the body.

Understanding PPO2 is essential for safe diving practices, particularly when using gas mixtures like Nitrox, which have higher concentrations of oxygen than regular air. As a diver descends, the pressure of all gases increases, thus increasing the partial pressure of oxygen. This can lead to toxic effects if the PPO2 exceeds safe levels, making it vital for divers to monitor and calculate the PPO2 based on their depth and gas mixture. Other options do not accurately capture the concept of partial pressure, missing the key definition that is foundational in dive planning and safety.