On Monday, March 23, 2020 at 7:19:53 AM UTC+13, BobWa43 wrote:

As aside, I would also note that pulse oximeters are great but they are not infallible. There are many reasons why you might get an incorrect reading, especially in the less expensive models.

Dr. Dan pointed out in his SoarRX article a few years ago that pulse oximeters are designed to be used sitting quietly in a chair, indoors and on the ground. Sitting in a glider in turbulence, a bit cold, and in bright sunshine is a rather different challenge for a device that relies on light transmission through the finger.