DC53
Guest
I have a question about M values.
I have read a lot on the issue including reading Deco for Divers once and then a second time really closely, including other books and materials. Anyway I thought I had a good grasp on it.
However, now I am doing divemaster training and PADI literature is expessing M values in what seems an entirely different way and it does not seem to make sense to me.
My understanding of M values is, on a mathematical level....
The degree of supersaturation of a compartment at any given depth, divided by what is 100% saturation at that given depth. This gives you a measure of the rapidity in which the dissolved gas in the compartment will offgas. You need a number greater than 1.0 in order to off gas but on a practical level as the number increases to say 1.5 or greater the likelihood that there will be symptomatic bubble formation increases steadily due to increasingly rapid offgassing. Mathematically if this equation is correct then the feet in depth will drop out leaving you an absolute number rather than a number of feet or some other units. You are simply left with a ratio that gives you an (estimated) measure of allowable supersaturation.
However, PADI stuff wants to express it in feet salt water which makes no sense to me at all.
Anyone care to clarify this for me?
I have read a lot on the issue including reading Deco for Divers once and then a second time really closely, including other books and materials. Anyway I thought I had a good grasp on it.
However, now I am doing divemaster training and PADI literature is expessing M values in what seems an entirely different way and it does not seem to make sense to me.
My understanding of M values is, on a mathematical level....
The degree of supersaturation of a compartment at any given depth, divided by what is 100% saturation at that given depth. This gives you a measure of the rapidity in which the dissolved gas in the compartment will offgas. You need a number greater than 1.0 in order to off gas but on a practical level as the number increases to say 1.5 or greater the likelihood that there will be symptomatic bubble formation increases steadily due to increasingly rapid offgassing. Mathematically if this equation is correct then the feet in depth will drop out leaving you an absolute number rather than a number of feet or some other units. You are simply left with a ratio that gives you an (estimated) measure of allowable supersaturation.
However, PADI stuff wants to express it in feet salt water which makes no sense to me at all.
Anyone care to clarify this for me?