The heat flux emitted by the near- and medium-IR radiators
was calculated by the time required for the temperature
to increase from 50 to 100 C (DT = 50 C) using a
black-painted reference copper plate (5 cm 5 cm
0.6 cm) with a thermocouple in the centre. The distance
between radiators and the black body was 50 cm. The radiators
produced heat fluxes for near-IR of 11–23 kW/m2
and for medium-IR of 5–11 kW/m2, corresponding to an
output power between 25% and 100% for both wavelengths.
To guarantee uniform heat flux, the black body
was always placed in the same position in the oven