Series 6 background measurements when not wearing the watch

[hyperfeel]

I noticed today that the sensors on the back of the watch were lit up (green light) when it was just sitting on the table. Then I checked my heart rate measurements and there were background measurements taken at times when I wasn't wearing the watch. Has anyone else noticed similar issues or has this been an issue with previous watches?

 

[JBaby]

This is normal. I noticed it happen several times.

 

[nlkccom]

I noticed it quite often.