On Wed, 8 Oct 2003, Jeffrey Earl wrote:

> I'd be interested to know the difference between an
> ODS and a common household CO-detector. Are these
> simply two methods of expressing the same thing: not
> enough oxygen because it's been displaced by
> carbon-monoxide?

Nope, two different issues.

Carbon monoxide, which is a product of incomplete combustion, can kill you
even if there's sufficient oxygen in the air.  This is because the
hemoglobin in your blood, the chemical which transports oxygen, binds more
easily with CO than with oxygen.  If enough of your hemoglobin is rendered
useless by binding with CO, there's not enough to carry oxygen to your
brain and you die.

Lack of oxygen in the air, by itself, can also kill you.  Lack of oxygen
doesn't necessarily mean a surplus of CO, though, because a catalytic
heater produces mainly carbon dioxide (CO2) and water vapor.

There's actually a double whammy if the oxygen level gets low, because if
there's too little oxygen in the air for clean combustion the catalytic
heater will start producing carbon monoxide.  This can kill you quickly
because your body is absorbing oxygen less efficiently, *and* there's a
shortage of oxygen in the air.

David Brodbeck, N8SRE
'82 Diesel Westfalia
'94 Honda Civic Si