Heat release


Heat Release Rate is the key measurement required to assess the fire hazard of products and materials, as it quantifies fire size, rate of fire growth and consequently the release of associated smoke and toxic gases. It is measured using a technique called oxygen consumption calorimetry.


A new Rate of Heat Emission parameter has been introduced in EN 45545­2. This parameter is known as MARHE or Maximum Average Rate of Heat Emission. The heat release rate is determined using the oxygen consumption technique from which an Average Rate of Heat Emission (ARHE) is calculated. The maximum ARHE over the testing period is MARHE. The MARHE parameter was selected because it is not greatly affected by normal experimental variation or measurement noise. It has also proved to be a fairly robust measure of the propensity for fire development under real scale conditions.


ISO 5660­1 Cone Calorimeter


Heat release rate is determined with the Cone Calorimeter according to ISO 5660­1.


Thresholds concerning the potential heat release for almost all combustible materials and products used in the railway industry are required by EN 45545­2. These requirements depend on the end use of the product and the Hazard Level of the carriage.


The Cone Calorimeter is the most significant bench scale instrument in the field of fire testing because it measures important real fire properties of the material being tested, under a variety of pre­set conditions. These measurements can be used directly by researchers or can be used as data for input into correlation or mathematical models used to predict fire development.


Table 1: Requirements concerning Heat Release (MARHE) Requirement set Heat flux


R5, R20 R9 R8


R10


R19, R21 R1, R7


R6, R11 R12 R17 R2


50kW/m2 25kW/m2


The FTT Dual Cone Calorimeter has been the benchmark in this field for its ease of use, robustness, sophisticated software that guides users through the calibration, testing and report protocols. Building on this expertise FTT has developed a new generation of Cone Calorimeter called iCone® that utilise state­of­the­art technology to improve the efficiency and accuracy of the fire test process.


Test parameter and unit MARHE [kW/m2 ]


HL1 50 90 –


75 –


90 60 – –


Maximum threshold HL2 50 90 50


HL3 50 60 50


––– 50 90 90 60 90 –


50 60 60 60 60 90


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EN 45545-2:2013 – NEW F I R E C LASSIFICATIONS AND FIRE TES T METHODS FOR THE EUROPEAN RAILWAY INDUSTRY


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