[PSUBS-MAILIST] measurment of CO content.

[Erik Michael Muller <emm03@uow.edu.au>]

Hi folks,
I am new to the list, but am keen to construct a dry ambient
submersible...if I can get anywhere near enough money together.
Anyhow,
After scouring the archives and the web, I have been unable to find
any discussion on a way to measure the CO build up, real-time:

In the case of an ambient sub, I am thinking that for shallow depths
where air is not consumed very quickly, especially considering there
is no physical exertion, then the limit of dive time might be more a
dependant on how quickly CO builds up.  I suppose this is in turn
dependant on how big a volume you are breathing, but does anyone have
ideas of how soon the air becomes too toxic to usefully stay
awake?I.e., how many times can I realistically and safely breathe the
same volume of air?

This led onto a thought of how to measure CO content in the air. Does
anyone know of a simple way to do this?  My crazy brain went on to
design a device where the ambient air is bubbled through a solution
containing some colored pH indicator, which i thought would become
redder as carbonic acid from the CO in the air built up, although I am
not sure how practical this is. If anyone wants to try it, I would be
very interested to find out (red cabbage is hideously expensive in
Australia, and black market red cabbages are no good).

Anyhow, I hope I havent said anything outrageously silly/contraversial
or annoying...
Thanks!
E.Muller