The bias is smaller than the actual measurement error. The measurement error is around +/- 1. So a 96 reading means actual blood O2 of 95-97. The bias introd

The bias is smaller than the actual measurement error. The measurement error is around +/- 1. So a 96 reading means actual blood O2 of 95-97. The bias introduced by skin color is around 0.5. So a 96 reading means 95-97 in a white person and 94.5-96.5 in a black person. The bias from skin color isn't significant because the measurement itself is pretty inaccurate.