The regulation concerning the electrical and electronic material involves the material assessment for their fire behavior. The CREPIM is accredited by the COFRAC to lead some of the tests for this kind of application. The different tests in relation with this field are the following ones:
Ces normes font références à différents sous-essais permettant la classification des matériaux selon les résultats à ces essais.
This test consists in putting the material horizontally under a 500W flame to assess its fire behavior for the horizontal propagation. Thus, a propagation speed can be measured. The classification depends on the measured speed.
This test consists in putting the material vertically under a 500W flame to assess its fire behavior for the flame persistence and thus for the self-extinguishing. Moreover, the fall of burning fragments is checked during the all test. Flame persistence and glowing duration when the burner is taken away, the flame vertical propagation and the fall of droplets which cause or not the ignition of the cotton under the sample allow the material classification.
Les temps de persistance de flamme après retrait du brûleur et les temps d'incandescence après extinction de la flamme ainsi que la propagation verticale de la flamme et la chute de goutte enflammant ou non un coton situé sous l'éprouvette permet la classification du matériau.
This test completes the previous one allowing the V0 classification. The complementary test consists in, thanks to a 500W flame, assessing the drilling behavior of the material. If the material is resistant to the flame and there is no drilling, it can obtain a 5VA or a 5VB classification.
This vertical allumability test allows the assessment of a film behavior. As a test giving the vertical classification (V0, V1 or V2), the measured parameters are: the flame persistence and glowing duration when the burner is taken away, the flame vertical propagation and the fall of droplets which cause or not the ignition of the cotton under the sample.
This test leads to the determination of the minimal oxygen concentration, in addition with nitrogen, which will support the combustion of small vertical samples under some specific conditions. This test is realized at an ambient temperature of 23°C ± 2°C. Results are defined as limit oxygen index (LOI).
Principle : A little sample is hold horizontally in an atmosphere mixing oxygen and nitrogen in a transparent chimney. The superior extremity of the sample is ignited and the fire behavior is recorded to compare the combustion duration, the burned length and the specific limits of this combustion. By testing several samples in atmospheres composed by different oxygen concentrations, it is possible to determine the limit oxygen index.
This test simulates, for instance, an electrical or electronic surge on electronic cards. Indeed, the glow wire allows a really local application (on few millimeters) with real high temperature (up to 960°C).
The principle is to apply, for 30 seconds, the glow wire on a material to assess the combustion duration, the flame persistence after the withdrawal of the wire and the presence or not of fragments fall (burning or not).
The wire temperature can vary from the ambient temperature to 960°C allowing the determination of parameters as the GWFI one or the GWIT one or to validate the behavior at a given temperature (750°C, 850°C …).