Medically reviewed by Daniel More, MD A peak flow meter is used to measure your peak expiratory flow rate (PEFR). PEFR describes how quickly your lungs expel air during a forceful exhalation after you ...

The wires for that setup needed some shielding. Aluminum foil connected to the ground did the trick. For more HVAC projects check out this pinwheel flow meter and [Adam]’s piece on HVAC techs ...