As some of you know, my husband and I have been engaged in an ongoing wrangle about air-integrated gauges versus analog SPGs. As I was chewing on a gas consumption issue that was coming out differently depending on how I went to solve it, my husband opined that the real problem was that I couldn't accurately read my SPG. He felt I was probably several hundred psi off in my measurement of starting and ending pressures. His feeling was that the analog gauge would be much better, because you directly read the numbers, instead of having to interpret the position of a needle.
So we decided to check it out. We measured the pressure in seven different cylinders, ranging from 600 to 3500 psi, with each of the gauges. I read the SPG the way I would normally do during a dive (rounding to the closest 100 psi) and also as accurately as I could do it, with no rounding. The air-integrated unit was my husband's Suunto Cobra.
The results surprised both of us. The furthest apart the two measurements were was 70 psi, and that was on one of my rounding readings (on that tank, the "best" reading was only 19 psi off the Cobra). The closest I got was 6 psi.
Although this tells us nothing about which gauge is more ACCURATE, it does tell us that the results of using those gauges are quite consistent, and the issue I was having with the original problem is most likely NOT due to my inability to read my gauge accurately.
Thought this was interesting enough to share.
and nice SAC, dang little women :14: the wife dives 63's to my 80s!
