How accurate is the pulse oximeter? 
  • A pulse oximeter may also be less accurate with very low oxygen saturation levels (below 80%) or with very dark skin.
  • False high readings are also always obtained from smokers – readings are affected for up to four hours after smoking a cigarette (Dobson, 1993).
  • Most oximeters give a reading 2% over or 2% under what your saturation would be if obtained by an arterial blood gas. For example, if your oxygen saturation reads 92% on the pulse oximeter, it may be actually anywhere from 90 to 94%.