I've been wearing a Pulse Ox for a few days, which uses a Optoelectronics sensor. I've checked the reading three times by comparing with my radial pulse, count

I've been wearing a Pulse Ox for a few days, which uses a Optoelectronics sensor. I'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. That's when fairly inactive, though. Will have to check it's consistent at much higher pulse rates.