Peak flow meters are small, affordable, handheld devices that evaluate how well you can exhale air from your lungs. How much air you can exhale in a single "quick blast" is what determines air flow. To measure the amount of air forced out of your lungs, peak flow meters are available in two ranges.
To determine the accuracy of the peak flow meter in screening for OAD and to test the correlation between PEFR measurement by the device and conventional spirometer.