2019 Volume 61 Issue 195 Pages 37-42
Hydrogen flame was visualized by imaging at 309 nm and about 10 μm. The ultra violet light at 309 nm was the emission spectrum of the OH radical, and the far infrared light at about 10 μm was the heat ray of the water vapor formed during combustion. The ultra violet image was amplified by an image intensifier. These images were converted the binarized-images using a threshold level of a brightness value. The spatial area that the ultra violet and far infrared light are emitted was extracted, and the flame image was displayed on the background image which was obtained simultaneously. The use of this method allowed imaging of hydrogen flame in outdoor, daylight conditions, up to a distance of 30 m. In addition, a hydrogen flame visualization method by imaging near infrared light was developed. Hydrogen flame was visualized by imaging at 950 nm, which coincides with the principal peak in the emission spectrum of the H2O molecule. The background image at 900 nm was obtained simultaneously, and the spatial region corresponding to the flame image was extracted by using differential imaging. The use of this method allowed imaging of hydrogen flame in outdoor, daylight conditions, up to a distance of 20 m.