nstrument 0769-89280808/4000711808 office chair durability tester HD-104 Description: Haida instrument 076989280808/4000711808 machine is used for determining the quality and life of the rotating office chair. The chair casters fixed on the turntable, the seat surface lend weight, then the provisions of the speed and frequency of rotation Legs for testing. Design Standards: American BIFMA standard office chair durability tester main technical parameters: Seat height: 350 ~ 600 mm or designated load power: 225 Lb or designated Wheel diameter: Φ700 mm test speed: 6 rev / min or desig