Abstract: The experiments of smoke characteristics of the reduced scale test fires were carried out based on the 4 standard test fires. The change rule of smoke characteristics of test fire in the process of gradual reduction of its scale was studied and the change of the obscuration coefficient of fire smoke with time was analyzed. Alarm response characteristics of rack fire detector, inspiratory smoke fire detector and point smoke fire detector to test fire of various scales was analyzed too. Suggestions for fire test with reduced scale suitable for detection and evaluation of high sensitive fire detectors were given.

Key words: test fire, reduced scale, high sensitivity fire detector, smoke characteristics, storage rack