Main parameters
Critical radiant flux CHF (kW/㎡) : The lowest value of either the radiant flux (CHF) at the point where the flame is extinguished or the radiant flux (HF-30) at the farthest position where the flame propagates within 30 minutes (i.e., the radiant flux at the farthest distance the flame propagates within 30 minutes).
2. The radiation flux corresponding to the farthest distance of flame propagation on the specimen at the beginning of the HF-X (kW/㎡) test for X minutes.
3. Flame propagation distance: The maximum distance that a continuous flame can travel along the length of the specimen within a specified time.

EN 11925-2: To determine the flammability of building products by directly striking a vertically placed sample with a small flame in the absence of external radiation.

These test standards are used to evaluate different aspects of the fire resistance performance of products and provide information on factors such as ignition, flame spread, smoke generation and heat release. The results of these tests are used to classify products based on their fire resistance performance, while also helping designers and manufacturers develop safer and more fire-resistant products.