On Monday, March 23, 2020 at 12:44:30 PM UTC-4, Duster wrote:
A pulse oximeter is quite reliable at cold altitudes in turbulence.

Another factor to ponder is the effect of bright sunshine on a device that depends on a red LED.

https://www.danlj.org/~danlj/Soaring...-p18-20-22.pdf


On the other hand, pulse oximeter ARE designed to work indoors sitting quietly in a chair or resting in bed.