What is the first step in preparing a Nitrox tank for use?

The first step in preparing a Nitrox tank for use is analyzing the gas mixture to confirm the oxygen percentage. This is critical because the composition of the gas is paramount for ensuring safety and effectiveness during a dive. Nitrox mixtures typically have a higher oxygen content compared to regular air, which affects both the planning of dives and the maximum operating depth. By confirming the oxygen percentage, a diver can also ensure that the mixture complies with the intended use and avoids the risks of oxygen toxicity that can arise from higher pressures of oxygen at depth.

Going through this process first guarantees that the diver is aware of the specific gas mixture they're about to utilize, allowing for appropriate dive planning and ensuring that they adhere to safe diving practices. This step is foundational, setting the stage for all subsequent safety checks and preparations.