And not, We are not talking about a small tattoo that you wear on your wristWe are talking about wearing that specific part of our body completely tattooed. Apparently the various tests that are being carried out with the Apple watch by users who already have it on their wrists, explain that tattoos in that area prevent a correct reading of the watch's sensors. The data shown by the device in the area where we have tattoos may be wrong or even block the Watch with the code previously set by the user, that is, the watch's sensors notice that they are not in contact with the skin and that does the security code set by the user is activated.
The truth is that all this only happens as soon as we put the watch on a skin with tattoos, it has nothing to do with the pigments of the skin or problems with the sensors of the device. The sensors that the Apple watch incorporates emit infrared light towards our skin (green), this light is returned to the clock to get the data and when we have tattoos the ink of these becomes a kind of 'screen' that makes the measurements erroneous or even null.
At first Apple does not comment on this issue of tattoos and the incompatibility of this type of sensors, but it does mention on its website that in some cases the measurement of the pulse could be impossible, but does not specify anything about tattoos. The problem seems quite evident in this sense if we look for example in tests carried out by iMore directly onto a tattooed skin and the Watch seems to fail, just like on Reddit and other media. This type of heart sensor is used in other quantifier watches and bracelets and the result seems to be the same in these cases, the sensor fails.