SL-FL73 BS 476-7 Surface Spread Flame Tester Unlock faster, more reliable fire safety certification for your wall and ceiling linings with the SL‑FL73 - the ultimate solution for BS 476‑7 surface spread flame testing. Product Overview The SL‑FL73 Surface Spread Flame Tester is a reaction‑to‑fire test system designed for wall and ceiling lining materials, measuring the lateral spread of flame along the surface of vertically oriented specimens under opposed flow conditions. It