TRAINING Time to Tighten the Standards: A Call for Rigor in Nitrox Gas Analysis – by Joel Silverstein, www.joelsilverstein.com
Joel is an industry leader and a Technical Diving Instructor Trainer (TDI) who has authored nitrox and mixed gas training materials for organizations such as NAUI, YMCA, and NOAA. Since 1990, he has mixed and ana- lyzed diving gases and manufactured thousands of nitrox analyzers through his company, Tech Diving Limited. As an experienced expedition leader and contributor to the NOAA Diving Manual, Joel is dedicated to improving div- ing safety and professional standards
In the early days of enriched air ni- trox (EANx) diving, precision and discipline were paramount. Analyzing gas was a personal responsibility, a rit- ual step between tank pickup and splashdown. Today, many divers re- ceive pre-labeled cylinders with no
Most oxygen analyzers use electrochemical oxygen sen- sors. They're convenient, portable, and cheap. But they drift. They age. And they require proper calibration every time they are used. NOAA guidelines suggest calibration should bracket the expected sample, either with a zero gas (like nitrogen or helium) and a span gas (such as compressed air or a known oxygen mix). But what we often see is a quick “calibration” using ambient air – assumed to be 20.9% – without regard for flow rate, humidity, temperature, or sensor age. Waving it in the air is not enough. A typical electrochemical sensor's output can be off by 2–5% if it is not properly calibrated. Add in an old sensor, fluctuating flow rates, and imprecise sampling methods,
witness to analysis and often no analyzer in sight. This isn’t nostalgia – it’s a warning. As professionals – whether at resorts, liveaboards, or training organizations – we share the responsibility to uphold the standards that protect our clients and colleagues. Many have become too casual. That complacency is eroding diving safety. Analyzers Are Only as Good as Their Calibration
Made with FlippingBook - Online Brochure Maker