Originally Posted by
grimmrad
@ DocRohan: Carboxy-Hemoglobin - CO binds 250-stronger to Hgb than oxygen, so if samples were to be retrieved containing erythrocytes it should be possible to evaluate that to indicate a fire. Osmotic strengths will have the cells burst but if the Hgb is not washed out it should be possible for forensics to evaluate that, it would not interfere with the binding affinity of gasses to Hgb. Ionic strength (9% NaCl in sea vs 0.9% physiologic conditions) could interfere with the binding of CO2 to Hgb's amine-groups but that accounts for only 10% of the binding.
Carboxyhemoglobin occurs naturally in the blood and its levels can be further elevated in smokers. So you can detect an exposure that is high enough to cause acute poisoning, but you can't confidently detect, say, 10% of that exposure.
If there were indeed 2 pings: feasible that one signal would be carried 600 km and heard by the other device?
Roughly as feasible as having a rock band perform an open-air concert in New York City and hearing their songs in a field in Ohio. (Sound attenuation in air at 1 kHz is similar to sound attenuation in seawater at 37 kHz.)
In other words, we have too many pingers.