UL 962A:2023 Clause 38 Rigid Supporting Surface

For impact testing per UL 962A:2023 Clause 38, the rigid supporting surface consists of a layer of nominal 25 mm (1 in) tongue-and-groove oak flooring (actual dimensions 18 mm by 57 mm or 3/4 in by 2-1/4 in) mounted on two layers of nominal 19 mm (3/4 in) plywood. This assembly rests on a concrete floor or equivalent nonresilient substrate during testing. The rigid backing surface comprises 19 mm (3/4 in) plywood over a concrete or equivalent nonresilient rigid surface. UL 962A:2023 Clause 38.1.5 Tags: SMT-UL962AC38