QUANTITY-OF-AIRFLOW CHECKER FOR VENTILATION GRILL AND VENTILATION GRILL PROVIDED WITH QUANTITY-OF-AIRFLOW CHECKER

摘要

PROBLEM TO BE SOLVED: To obtain a quantity-of-airflow checker which displays the ventilation degree of air which is sucked and evacuated from a ventilation grill. SOLUTION: The checker has a bottomed cylindrical checker body 1, and a piston-shaped partition body 2 which is arranged at its inside. A display shaft 3 which is integrated with the partition body 2 protrudes to the outside of the checker body 1. The partition body 2 is moved and urged in a direction in which the display shaft 3 protrudes by a resistance spring 4. A first partition chamber 10 which is partitioned by the partition body 2 is bonded to a vent 19 in a grill body 16. When a negative pressure is made to act on the first partition chamber 10, the partition body 2 is moved against the urging force of the resistance spring 4. When its movement state is displayed by a display means 25, a ventilation degree is known.