The test consists of dropping a steel ball on a foam specimen and noting the height of rebound. The ball rebound tester consists of a 40±4 mm inside diameter vertical clear plastic tube, such as acrylic, into which a 16±0.05mm diameter steel ball is released by a magnet or other device. The steel ball must be released so that it falls without rotation.
Testing Steps:
(1) Center the specimen at the base of the tube and adjust the height of the tube so that zero rebound is 16mm above the surface of the foam specimen.
(2) Mount the steel ball on the release mechanism, then drop it and note the maximum rebound height. If the ball strikes the tube on the drop or rebound, the value obtained is invalid. This condition is usually due to the tube not being vertical or irregularities on the specimen surface. In order to minimize parallax error, the circles on the tube in the region where the percent rebound is read must appear as lines.
(3)Make an additional two drops on the same specimen in the same location unless agreed upon by purchaser and supplier.
Ball falling distance:460±0.5%mm(China standard) 500±0.5%mm(American standard)
Ball diameter: Φ16±0.05 mm
Falling ball rebound rate accuracy:1.5
The tested sample size:100 mm(L)×100 mm(W)×50mm(H)
Standards:GB/T6670-97,ASTM(American standard)D3574 and ISO8307