Readings are higher than normal or inaccurate

Possible Cause #1
Unclean Mouthpiece

Try sterilizing the mouthpiece in hot water or use a new mouthpiece

Possible Cause #2
Blowing too hard

Blow a long and steady breath into the unit until it stops beeping or till you hear/feel a double click/beep.

Possible Cause #3
Unit due for calibration

Book your unit in for calibration at