Interesting.... I wonder if the oposite has also happened. I tend to
use a lot more O2 than others using the EDS at similar altitudes; more
than different breathing patterns and/or metabolism would easily
explain. Given that these devices are calibrated by the factory prior
to shipment , and, presumably, could shift, do they ever require
checking and recalibration? For those using this device w/out
reference to an oximeter, such checking and recalibration might well be
important.

Ray Warshaw
1LK