Rigid Supporting Surface UL 962A:2023 Clause 38

For the impact tests, the rigid supporting surface consists of a layer of nominal 25 mm (1 in) tongue-and-groove oak flooring (actual size 18 by 57 mm or 3/4 by 2-1/4 in) mounted on two layers of nominal 19 mm (3/4 in) plywood. The assembly rests on a concrete floor or an equivalent nonresilient floor during the test. The rigid backing surface consists of 19 mm (3/4 in) plywood over a rigid surface of concrete. An equivalent nonresilient backing surface may be used. UL 962A:2023 Clause 38.1.5 Tags: SMT-UL962AC38