Use airflow readings as a comparison—not a certification.
Outlet velocity changes with the dryer, vent geometry, exterior hood, wind and measurement position. Consistency matters more than chasing one universal number.
Before cleaning
Use the same dryer cycle, allow the dryer to reach stable operation, keep doors and windows in comparable positions, and hold the meter at a marked location outside the termination without obstructing the flap. Record the reading and conditions.
After cleaning
Reconnect the dryer correctly, repeat the same cycle and measurement position, then record the result. A meaningful increase supports that restriction was reduced, but low or unchanged airflow may require appliance diagnosis, duct inspection or professional service.
What the meter cannot tell you
An anemometer cannot see a separated joint, confirm that every surface is clean, establish code compliance or guarantee fire safety. Photographs, symptoms and vent configuration remain important.