https://us.community.samsung.com/t5/Samsung-Apps-and-Services/Samsung-Health-Oxygen-saturation-removed/m-p/1431459#M26406 <P>The SpO2 sensor on the phones measurement has a infrared sensor which measures un-oxygenated blood, but a UV sensor is also needed to measure the oxygenated blood, which the phones and watches do not have.&nbsp; So they guestimate the O2 levels using only one side of the equation.&nbsp; Numerous articles and YouTube videos have highlighted the poor accuracy of the phones and watches.&nbsp; I believe Samsung decided no dodge the lawsuit bullet that could come if someone claims that false SpO2 readings caused them damage.&nbsp; It probably will not return until/if they put in a UV sensor as well.</P><P>&nbsp;</P><P>I use it anyway but like to check my phone levels with a doctors finger tip measuring tool which has both sensors and is more accurate.</P> Fri, 18 Sep 2020 16:14:18 GMT Ezriderz 2020-09-18T16:14:18Z