In a new video, The Quantified Scientist’s Rob ter Horst compares the new Apple Watch Series 12’s heart rate sensor against a Polar H10 ECG chest strap. Here’s what he found.
Source: [9to5Mac](https://9to5mac.com/2026/09/18/the-quantified-scientist-tests-the-apple-watch-series-12s-new-heart-rate-sensor/)