Spent a day with an old saturation diver who changed how I look at gas mixing

He told me he used to eyeball his heliox mixes back in the 80s with nothing but a stopwatch and a calculator. I've been relying on digital analyzers for years but he showed me a manual trick for checking O2 partial pressure that I never even thought of. Any of you guys still use old school methods for your gas blends?

2 comments

2 Comments

thomas.tyler13d ago

Used to be one of those guys who trusted the digital gadgets completely. Thought the old timers were just being stubborn or nostalgic. But then I tried that stopwatch method on a trimix fill just out of curiosity and it matched my analyzer within a tenth of a percent. That changed my mind real quick. Not saying I'm throwing away my electronics, but I definitely see the value in knowing how to do it the hard way. Your mileage may vary but that kind of practical knowledge sticks with you longer than a battery powered screen.

terry_lewis2113d ago

Exactly what happened to me with partial pressure blending a few years back... I had a buddy show me how to do the math on a slate before I even turned the valve. First time I calculated oxy percentages from the pressure log and cross-checked with my analyzer it was off by 0.3% and I realized the old school method catches bad gas mixes way before the digital stuff does. Now I always build my own chart for the specific tank size and whip it out for the first blend of the session just to be safe.