Deeply Safe Labs
Registered
Greetings divers,
Over the past half year or so, we have been conducting tests on dive computers using a miniature hyperbaric chamber. Some of the results we have found, regarding repetitive diving, we believe could be of concern. This was identified with our first test protocol, two square dives of 30 minutes at 30 meters (100 ft), spaced by a 90 minutes surface interval. The results show that some dive computers, specifically these that implement ZH-L16 C, compute significantly lower decompression times than other computers for the second dive while being similar on the first dive, some leeway considered. This aroused suspiscions that these implementations did not account for repetitive dives in any other way that simple offgasing during the surface interval. We first confirmed this with theoretical calculations, and contacted relevent manufacturers to bring this to their attention. Some of them simply confirmed that absence of additionnal procedures, without bringing any argument to why they are not taking into account aggravating factors, like the right-left pulmonary shunt.
Following this discovery, we have continued on testing computers, and have decided to upload a website showcasing extended results as well as some additional computers models. More recently, we added another test protocol, designed by Professor A. A. Bühlmann in the 1994 UHMS workshop named "The Effectiveness of Dive Computers in Repetitive Diving", consisting of 6 dives for 16 minutes at 30 meters, spaced by 75 minutes of surface interval. We found the results to show even more cause for concern.
We have detailed why we find these results concerning on the website, under the sections "Forewords", "Test conditions" and "Guide to interpreting results". Therefore, I will not be detailing the reasons in this initial post, as it would be way too long, so we encourage you to read said sections instead.
The website is available at the following link: Deeply Safe Labs (works best on a computer screen).
Even though I am a former technical manager, computer specialized, from a long installed diving equipment manufacturer, I am no Professor, Doctor, or any kind of such experts. I have been doing this in collaboration just with experienced divers having a strong interest in decompression theory. We are eager to read what any of you may think about our analysis, and will gladly answer any question you may have on our work.
Best regards,
Eric,
Deeply Safe Labs.
Over the past half year or so, we have been conducting tests on dive computers using a miniature hyperbaric chamber. Some of the results we have found, regarding repetitive diving, we believe could be of concern. This was identified with our first test protocol, two square dives of 30 minutes at 30 meters (100 ft), spaced by a 90 minutes surface interval. The results show that some dive computers, specifically these that implement ZH-L16 C, compute significantly lower decompression times than other computers for the second dive while being similar on the first dive, some leeway considered. This aroused suspiscions that these implementations did not account for repetitive dives in any other way that simple offgasing during the surface interval. We first confirmed this with theoretical calculations, and contacted relevent manufacturers to bring this to their attention. Some of them simply confirmed that absence of additionnal procedures, without bringing any argument to why they are not taking into account aggravating factors, like the right-left pulmonary shunt.
Following this discovery, we have continued on testing computers, and have decided to upload a website showcasing extended results as well as some additional computers models. More recently, we added another test protocol, designed by Professor A. A. Bühlmann in the 1994 UHMS workshop named "The Effectiveness of Dive Computers in Repetitive Diving", consisting of 6 dives for 16 minutes at 30 meters, spaced by 75 minutes of surface interval. We found the results to show even more cause for concern.
We have detailed why we find these results concerning on the website, under the sections "Forewords", "Test conditions" and "Guide to interpreting results". Therefore, I will not be detailing the reasons in this initial post, as it would be way too long, so we encourage you to read said sections instead.
The website is available at the following link: Deeply Safe Labs (works best on a computer screen).
Even though I am a former technical manager, computer specialized, from a long installed diving equipment manufacturer, I am no Professor, Doctor, or any kind of such experts. I have been doing this in collaboration just with experienced divers having a strong interest in decompression theory. We are eager to read what any of you may think about our analysis, and will gladly answer any question you may have on our work.
Best regards,
Eric,
Deeply Safe Labs.