ISO 6942 is a test method in which a sample of material is exposed to the thermal radiation from a bank of silicon carbide heating rods and the energy transfer to a copper calorimeter measured. The equipment is capable of emitting thermal radiation up to 90 Kw/m2 when the power controller setting is maximum and the calorimeter is placed at its closest approach location. The test method calls for a heat flux 80 Kw/m2 or lower and there are two method of reducing the energy received by the calorimeter : turning down the power to the rods or changing the separation between the rods and calorimeter. Either method will allow material evaluation at heat fluxes of Kw/m2 or lower but turning down the power will result in a wavelength shift to longer wavelengths as the rod surface temperature will be reduced.