HR inaccurate when I sweat


I got myself a vivosmart 4 two weeks ago and I am really frustrated by the fact that HR is completely inaccurate whenever there is sweat between my wrist and the machine when I exercise!

I have followed a few tips - like wearing it in the right wrist zone or having it not too tight or too loose - and it seems to be fairly accurate in the beginning, but when I start to sweat the HR shows 60-70bpm when in reality I'm at 120/130......

I mean, when I think of a wrist band to measure my performance while doing sports, I would expect that it would work if there is sweat on it!

Anyone else experiencing the same issue?