What should the oximeter show in reading. Some times within 5 sec it gives 97 98 reading. Sometimes it takes 15 20 sec to give reading. Sometimes it gives very low value like 90 at first and then after few seconds it becomes 96 97. Sometimes it shows 98 at first and then after few seconds decreases. Then which value should I take. It shows many values between 90 to 98. Also is this normal phenomena? Fluctuation in value is normal? Plz explain someone. Which value to accept.