Comparison of severity of exposure in ASTM E 119 and ISO 834 fire resistance tests

Using specimens similar to those described in the draft revision of ASTM E 119, tests were conducted in floor and wall fire test furnaces. The tests were designed to compare the practical consequences of following the ASTM E 119 and ISO 834 specifications for measuring and controlling the nominal furnace temperature. It has been found that in fire tests of shorter duration, perhaps up to 1.5 h, the ASTM test is slightly more severe than the ISO test. In longer tests the difference in severities is negligible. Some observations concerning the non-uniformity of heat absorption by the test specimen point to the importance of proper furnace design in the satisfactory performance of test furnaces.