2airishuman
Contributor
I too have seen instructors dive without an SPG. There are obvious risks.
Off topic, if you have a good sense of pitch, you can determine whether a cylinder is full by tapping on it and listening.
Be careful. It's tempting to believe what you want to believe. Consider:
1) The likelihood of an erroneously high reading during a dive, which poses a safety problem.
2) The likelihood of an obvious failure first detected during a dive, which should lead to the dive being called early.
3) the likelihood of a failure detected during predive checks, which should lead to the dive being cancelled or backup equipment used
4) The average life of the system, which has cost implications.
The SPG failures I have seen involve flooding, air leaks, or progressive stickiness or loss of accuracy, which only contribute to #4 as long as maintenance procedures are followed so the problems are caught early.
Typically I carry a spare reg set that includes an SPG. If I have SPG problems before a dive, I can either swap SPGs, or just switch to my other reg set.
Off topic, if you have a good sense of pitch, you can determine whether a cylinder is full by tapping on it and listening.
We have been tracking transmitter failures relative to pressure gauge failures. Just had another pressure gauge failure yesterday. The gauge read 600 psi while totally empty. Last week we had one transmitter that was reading pressure intermittently. We had two high pressure hoses that were leaking.
In our unscientific study, it seems to be about even over the last two years. Anything man-make can fail.
Be careful. It's tempting to believe what you want to believe. Consider:
- Are you including dead batteries in your hoseless AI failure count? Why or why not?
- Does your population of divers have equal numbers of hoseless AIs and SPGs?
- Are the SPGs in your population of divers the same age as the hoseless AIs? If not, what effect does this have on results?
1) The likelihood of an erroneously high reading during a dive, which poses a safety problem.
2) The likelihood of an obvious failure first detected during a dive, which should lead to the dive being called early.
3) the likelihood of a failure detected during predive checks, which should lead to the dive being cancelled or backup equipment used
4) The average life of the system, which has cost implications.
The SPG failures I have seen involve flooding, air leaks, or progressive stickiness or loss of accuracy, which only contribute to #4 as long as maintenance procedures are followed so the problems are caught early.
Do divers that use a pressure gauge carry a back-up?
Typically I carry a spare reg set that includes an SPG. If I have SPG problems before a dive, I can either swap SPGs, or just switch to my other reg set.