Registered Nurses' Association of Ontario

Nursing Best Practice Guidelines

How to Use a Peak Flow Meter

Follow these five steps for using a Peak Flow Meter:

  1. Move the indicator to the bottom of the numbered scale.
  2. Stand up, or sit upright.
  3. Take a deep breath in, and fill lungs completely.
  4. Place the mouthpiece in mouth and close lips around it.
  5. Blow out as hard and fast as possible in a single blow.
  • Write down the value. If coughing occurred, the value is inaccurate. Do not record.
  • Repeat the test.
  • Repeat steps 1 through 5 two more times.
  • Take the highest result of the three, and record.