I&#x27;ve been wearing a Pulse Ox for a few days, which uses a Optoelectronics sensor.<p>I&#x27;ve checked the reading three times by comparing with my radial pulse, counting against my wristwatch. Each time it was bang on, or within 2bpm.<p>That&#x27;s when fairly inactive, though. Will have to check it&#x27;s consistent at much higher pulse rates.