Pulse rate Alarm range: Consistent with the display range, the set step length is 5 bpm. Pulse rate range: 30 bpm~250 bpm. Pulse rate accuracy: ±1 bpm. Pulse rate sound: PR tone. SpO2 accuracy: +1% in the range of 90%~99%, +2% in the range of 70%~89%, other scope is not defined.