The rate of heat release during material combustion is an important parameter to measure the fire hazard, especially in a confined space, such as buildings, ships, and aircraft cabins. From the perspective of the rate of heat release, there are two experimental methods:
1. Study the heat release rate of the actual fire through the experiment of reduced size, such as ISO 5660 cone calorimeter, FAA microcalorimeter, etc.;
EN ISO5660-1 cone calorimetry method / ISO 5660-1 heat release rate MARHE please refer to: https://www.fire-test.com/newsinfo/2144910.html
2. The heat release rate in case of fire will be investigated through medium and large size experiments, such as SBI monomer combustion tester, ISO 9705 house corner calorimeter, large calorimeter, etc.
At present, countries in the world have developed more than 70 methods and standards for combustion experiments, which extend from microscale and small scale to large scale. Among the many experimental methods, although large-scale fire experiments can more roughly reflect the fire scenes when the real materials are finally applied, they are not suitable for widespread use in the field of research and testing because of the time-consuming and huge cost. At present, the most widely used experiments are small and micro experiments. One of the typical small experimental method is cone calorimetry, which has become one of the most important tests in the fire science research. The micro experiment was conducted with a microcalorimeter (MCC) based on the pyrolysis combustion flow calorimetry experiment method.
The microcalorimeter and the conical calorimeter is based on the principle of oxygen consumption, but it only needs a very small number of samples, after pyrolysis and then combustion, and then the oxygen loss in the combustion process can be determined by the concentration of oxygen and the flow rate of the combustion gas, so as to obtain the heat release rate. The experimental data can be associated with fire test data (cone calorimeter, OSU heat release rate tester), flammability test (high temperature oxygen index meter, UL 94 horizontal vertical flame combustion tester) and combustion test (oxygen bomb calorimeter). It is an efficient research tool to determine and predict the properties of fireproof materials. It is widely used in the evaluation of material performance, new product design, screening, etc., which greatly reduces the test cost, and is of great significance to the material research and exploration of universities and the majority of scientific research departments!
Test method for the microcalorimeter
The experimental method for pyrocombustion flow heat (The Parolysis Combustion Flow Calorimeter, PCFC) was proposed by Rehard E.Lyon, Richard N.Waiters and collaborators at the Federal Aviation Administration Laboratory (Federal Aviation Authority Laboratories). Rehard E.Lyon, Richard N.Waiters systematically described the principles and method of the paper Pyrolysis combustion flow calorimetry published in 2004.
The American Association for Materials and Experimentation (ASTM) has issued the standard ASTM D7309, The latest standard is ASTM D7309 Standard Test Method for Determining Flammability Characteristics of Plastics and Other Solid Materials Using Microscale Combustion Calorimetry (Standard Test Method for determining the Inflammable Characteristics of Plastics and Other Solid Materials with Micro-combustion Calorimeters). FTT in the UK, in cooperation with the Federal Aviation Administration (FAA), developed a microcalorimeter MCC based on the ASTM D7309 standard and introduced it to the market. The "micro" mainly refers to the very small sample quantity required for testing (typical value of 2~5mg).
Correlation of the microcalorimeter with the UL 94 test
Some studies have shown a quantitative correlation between the material intrinsic combustion performance parameters measured by microcalorimeter (MCC) and UL 94 grade. Typical associations include:
When HRC is> 400 / J (g .K), the material is HB;
When HRC = 200 J / (g .K) ~400J / (g .K), the material has self-quenching, may be V0 / V1 level;
When HRC <200 J / (g .K), the material is not easy to ignite and is usually grade V0.
In addition, Schartel et al. studied the flame retardant PC / ABS system with two-step decomposition reactions, and found that the sum sumHRC and the mean avgHRC of HRC corresponding to single-step decomposition also had some correlation with UL 94 grade.
Microcalorimeter features
The microcalorimeter only needs milligram samples to obtain the heat release rate (W / g), combustion heat (J / g) and ignition temperature (K) and other parameters, which can quickly and effectively determine the main combustion performance parameters of various plastics, wood, textiles or synthesis, and then get sufficient data on the combustion and flammable risk of materials.
Micro-heat meter features and advantages
Ability to produce quantitative results within several minutes
Automatic control of the temperature and gas flow rate
Small sample size
Both test furnaces have overtemperature protection
Technical specification of micro-heat meter
Test principle: pyrolysis combustion flow rate calorimetry method
Operating temperature range of the combustion chamber: 25~1000°C
Heating Rate: 0.4~4°C / s
Sample size: 1~20mg (typically 2-5mg)
Probe limit: 5 mW
Reproatability: ± 2%
Dimensions: 1050mm (high) 350mm (wide) 550mm (deep)
Microcalorimeter is a necessary test equipment in the fields of plastics, textiles, synthetic materials, flame retardant research and other fields. The combustion performance of materials can be quickly measured only by trace samples, which has a positive promotion effect in improving the research efficiency. Nanjing Smart provides ISO5660-1 micro heat meter heat release rate test, tel: +86 25 -86583475.
Nanjing Smart Contact information:
Tel.: +86 25 -8658 3475 +86 25 -86583465
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