Fire test methods heat release

ISO 5660-1 Reaction-to-Fire Tests—I leal Release, Smoke Production and Mass Loss Rate—Part 1 Heat Release Rate (Cone Calorimeter Method). International Organization for Standardization, Geneva, Switzerland. ISO 5660-2 Reaction-to-Fire Tests—I Ieat Release, Smoke Production and Mass Loss Rate—Part 2 Smoke Production Rate (Dynamic Measurement). International Organization for Standardization, Geneva, Switzerland. ISO 9705 Fire Tests—Reaction-to-Fire—Room Fire Test. International Organization for Standardization, Geneva, Switzerland. 

A number of modern full-scale fire test methods have been developed for products, relying on heat release rate measurements, such as those involving testing of upholstered furniture (ASTM E 153792 and CA TB 13391), mattresses (ASTM E 1590,85 CA TB 129,82 CA TB 603,88 16 CFR 1633,19 and ASTM F 1085 [Annexes A1 and A3]171), stacking chairs (ASTM E 1822172), electrical cables (ASTM D 5424,173 ASTM D 5537,174 and UL 1685123), plastic display stands (UL 1975),175 other decorative items (NFPA 289,176 a generic furniture calorimeter test), electrical equipment (UL 2043),120 or wall-lining products (NFPA 265,116 NFPA 286,115 ASTM E 2257,177 and ISO 9705178). In fact, room-corner tests are now being used in the codes, as alternatives to replace the... 

Fire-test method development has followed two separate but complementary paths. One path, theoretically oriented, is characterized by the measuring of scientifically-meaningful fire properties, such as mass loss and rate-of-heat release. This approach also includes the development of mathematical models incorporating these properties to predict propagation and flame spread. A new lab-scale apparatus, the "cone calorimeter" developed at NIST is an example of the hardware now available to measure these fire properties. 

A comparison of results for fire effluents from full scale and small scale fire tests has to be done in steps. A full scale fire is a developing event where temperature and major constitutions changes continously. A small scale fire test either take one instant of that developing stage and try model that or try to model the development in a smaller scale. On a priority one level rate of heat release, temperature, oxygen concentrations and the ratio of C02/C0 concentrations have to be similar for a comparison. The full scale fire experiments reaches a temperature of 900 C at the moment of flashover, while the small scale fire tests are reaching temperatures just above 400 °C for NT-FIRE 004 and the cone experiments. For the DIN 53436-method the temperature was set to 400 °C. 

The versatility and accuracy of the oxygen consumption method in heat release measurement was demonstrated. The critical measurements include flow rates and species concentrations. Some assumptions need to be invoked about (a) heat release per unit oxygen consumed and (b) chemical expansion factor, when flow rate into the system is not known. Errors in these assumptions are acceptable. As shown, the oxygen consumption method can be applied successfully in a fire endurance test to obtain heat release rates. Heat release rates can be useful for evaluating the performance of assemblies and can provide measures of heat contribution by the assemblies. The implementation of the heat release rate measurement in fire endurance testing depends on the design of the furnace. If the furnace has a stack or duct system in which gas flow and species concentrations can be measured, the calorimetry method is feasible. The information obtained can be useful in understanding the fire environment in which assemblies are tested. 

Method of Test for Fire and Smoke Characteristics of Electrical Wire and Cables, 1990. Standard Method of Test for Heat and Visible Smoke Release Rates for Materials and Products, 1990. 

Studies are currently being conducted on smoke development and heat release rate from treated and untreated wood and wood products (52,56). An evaluation of the available treatment systems for wood shingles and shakes was completed using artificial weathering (11). A further development from this work was a new ASTM Standard Method D2898 (67,68) for testing durability of fire-retardant treatment of wood. 

Often it is very difficult to determine the burning behavior of complex objects on the basis of the performance of its individual components in bench-scale reaction-to-fire tests. It is much more practical to measure the heat release rate and related properties for the complete object. This requires a large-scale test. In other cases, it is not possible to capture certain aspects of real fire behavior such as melting, delamination, joint effects, etc., in a bench-scale test. A large-scale test is needed to assess these effects. Two commonly used large-scale reaction-to-fire tests are test methods are discussed as follows. 

In the early 1980s, Vytenis Babrauskas, at the NIST (then NBS), developed a more advanced test method to measure RHR the cone calorimeter (ASTM E 1354).71164 This fire test instrument can also be used to assess other fire properties, the most important of which are the ignitability (as discussed earlier), mass loss, and smoke released. Moreover, results from this instrument correlate with those from full-scale fires.165-170 To obtain the best overall understanding of the fire performance of the materials, it is important to test the materials under a variety of conditions. Therefore, tests are often conducted at a variety of incident heat fluxes. The peak rates of heat release (and total heat released) of the same materials shown in Table 21.15 at each incident flux, are shown in Table 21.16.147... 

EN 50399, Common test methods for cables under fire conditions—Heat release and smoke production measurement on cables during flame spread test—Test apparatus, procedures, results, European Committee for Standardization, Brussels, Belgium. 

ISO 5660 Reaction-To-Fire Tests—Heat Release, Smoke Production And Mass Loss Rate—Part 1 Heat Release Rate (Cone Calorimeter Method), ISO, Geneva, Switzerland, 2002. 

Basic Mechanisms. Finally, further work is necessary on fundamental mechanisms of individual fire retardants. These mechanisms are a function of the particular chemicals involved and the environmental conditions of the fire exposure. There is a need to establish common methods and conditions for determining these mechanisms in order to compare different treatments. This would give us a better understanding of how these compounds work in action and would provide a more efficient approach for formulating fire-retardant systems than a trial and error approach. Correlations also need to be established between rapid precise thermal analysis methods and standard combustion tests. Retardant formulations could be evaluated initially on smaller (research and development size) samples. The more promising treatments could be tested for flame-spread index, heat release rate, and toxic smoke production. 

Noncombustible (NFPA 13)—A material that, in the form in which it is used and under the conditions anticipated, will not ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat. Materials that are reported as passing ASTM El 36, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750°C, shall be considered noncombustible materials. 

ISO 5660-1 (1993), Fire test—Reaction to fire—Part 1, Rate of heat release from building products (cone calorimeter method),... 

ISO 5660-1 2002, Reaction-to-fire tests Heat release, smoke production and mass loss rate Part 1 heat release rate (cone calorimetra method)... 

ASTM E1354-04 (standard test method for heat and visible smoke release rates for materials and products using an oxygen consumption calorimeter) and ISO 5660-1 2002 (reaction-to-fire tests-heat release, smoke production, and mass loss rate - part 1 heat release rate, cone calorimeter method) for heat release and oxygen consumption. 

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