How smooth is the heart rate sensor? Any concern about it trapping dirt and getting gunked up?

[jean15paul]

Just wondering. I can imagine the heart rate sensor getting sweaty trapping dirt and dead skin, and just getting generally gunked up and grimey, with it being on the back of your watch against your wrist. How smooth is the sensor? Is it flush with the watch or recessed? In either case does anyone know if it will get dirty and affect performance? How do you plan to keep it clean?

 

[kch50428]

A microfiber cloth... maybe a spritz of an eyeglass cleaning solution on the cloth if the device gets particularly soiled - same as I do with my iPhone and iPad...

 

[Bigeric23]

I imagine you'll have to do some general cleaning occasionally, but I don't see it being any big issue to worry about.

 

[jean15paul]

Do you know if the sensors are flush with the back or are they recessed? I couldn't tell from the pics I just looked at.