A peak flow meter is an inexpensive, pocket-size device that
measures peak expiratory flow (PEF), or how much air a person can breathe out. To
measure PEF, the person takes a deep breath and then blows into a tube on the
peak flow meter as hard and as fast as possible. This can be done at
John Pope, MD - Pediatrics & Lora J. Stewart, MD - Allergy and Immunology
How this information was developed to help you make better health decisions.