Introduction to infrared radiation
Infrared radiation is a natural form of radiation which accounts for nearly 50 % of the total radiation spectrum of the sun. When infrared radiation comes into contact with our skin it triggers a pleasant warming sensation. This is why it is also affectionately known as "heat radiation". Without the daily dose infrared radiation from the sun there would be no life on earth.
The word "infrared" (which stems from the Latin 'infra' meaning below or beyond) alludes to an area of electromagnetic radiation that lies beyond the red end of the visible light spectrum and does not contain any UV radiation.
There are, however, significant differences between the various infrared fields and wavelengths. Infrared rays can be broken down into the following three categories:
Short-wave infrared (IR-A)
Medium-wave infrared (IR-B)
Long-wave infrared (IR-C)
Infrared heated units in comparison
Emitter |
Infrared halogen lamp
|
Quartz |
Resistance heating
|
Degree of efficiency
|
92 % | 60% | 40% |
Heated phase
|
1 sec (90 % capacity) |
30 sec (90 % capacity) | 5 sec (90 % capacity) |
Emission peak
|
12 µm |
22 µm | 4 µm |
Visible light
|
6 % |
0,5 % | 0,05 % |
Spectrum |
34 % IR-A 50 % IR-B 10 % IR-C |
3,5 % IR-A
50 % IR-B 46 % IR-C |
1 % IR-A
14 % IR-B 85 % IR-C |
Wind sensitivity
|
No | High |
Very high |
Colour sensitivity
|
High | Medium | Low |
