The Apple Watch Series 6 includes an oxygen saturation sensor and Saturation app to measure oxygen levels in the blood. Thanks to this app you can measure the saturation value of your blood directly from your wrist and this is also done automatically in the background.
The background measurements are important because it gives you even more insight into your overall health. The Apple Watch uses a large amount of infrared light while measuring the oxygen content. This can be visible to you in the dark because it can happen that the light ‘leaks’. Therefore it is possible to disable the background measurements for theater and sleep mode.
How can the Apple Watch measure saturation?
The Apple Watch Series 6 optical heart rate sensor also includes an oxygen saturation sensor. During a saturation measurement, the crystal on the back shines infrared light on your wrist, but also green and red LED light. Photodiodes then measure the amount of light that is reflected. Based on this data, the color of your blood is calculated with advanced algorithms. The color determines your saturation value: bright red blood contains more oxygen than dark red blood.
Disable background measurements Saturation app
As with your heart rate, the Apple Watch will also measure the oxygen in your blood in the background. Using the steps below, you can disable the measurement in the background in its entirety or for certain situations.
- Open the Apple Watch app on your iPhone
- Go to ‘My Watch’
- Tap ‘Saturation’
Turn off the ‘Saturation measurements’ option if you do not want the Apple Watch to measure the oxygen level in your blood in the background. If you choose this, you can only manually measure the values via the Saturation app.
Via the option ‘Allow background measurements’ you can disable the options ‘In sleep mode’ and ‘In theater mode’. When you do this, the Apple Watch will not take measurements while sleeping or in the theater if you use the mode.