Heating by Infrared![Spektrum Infrarot]()
Technological Background of IR Radiation
Infrared beams are invisible to the human eye.
According to DIN 5031, IR radiation lies in the spectral range from 0,78 μm (= 780 nm) to 10,0 μm.
This quite big range can be divided into the following areas:
- IR-A or short wave (0,78 μm to 1,4 μm)
- IR-B or medium wave (1,4 μm to 3,00 μm)
- IR-C or long wave (3,00 μm to 10,0 μm)
Radiation Source Ralotherm
What are Ralotherm Lamps made of?
Ralotherm IR-A-lamps are - technologically thinking - halogen incandescent lamps: Most important components are the quartz tube and the tungsten filament as heating coil, the gas-filling contains halogen in order to avoid blackening and prolong the lamp's life.
The filament has been designed so that the maximum radiation is situated at a wavelength of about
1100nm (1,1µm), but it also emits visible light. In addition, it can be segmented and so adapted to the application that the heat is distributed over the length as needed.
The bulb material quartz glass is practically translucent for radiation below 4000nm wave length, so that this does not cause any losses. Should the radiation be emitted to one side, the bulb wall can be coated with a reflector made of aluminium oxide at the opposing side, which increases the efficiency of the heating process further.
Operation = Simple!
For operation, just a mains connection with 235 V (for some types also 400 V) and a suitable fitting / socket is needed.
So, they can be installed in machines and production lines with minimum space and maintenance requirements and show accurate controllability and high efficiency.
Due to loads of variations, the lamps are available in different geometrical shapes and with various bases or end-connectors. There is a suitable lamp for almost any application.
The operating position preferred should be horizontal, a slight tilt of up to 15° upwards or downwards will be tolerated by the lamp (without deviations in technical or service live data).
Ralotherm IR lamps are nearly maintenance-free, just need to be replaced at their life's end.
Notes on Operation
Ralotherm lamps are sensitive towards anything containing sodium due to their quartz glass bulb. hey should never be touched with bare fingers since oils or other residue causes diversification of the quartz which leads to premature lamp failure. Prior to operating the lamp, any fingerprints must be removed by using a suitable cleaning solvent.
Lamps are sensitive to torsion forces, i.e. the lamp must not be clamped at the seals during installation. During operation, tensions caused by different expansion coefficients must be avoided. According to EN 60061-2 the contact force of lamp holders R7s shall be between 20 and 35 N. Lower contact pressure can lead to corrosion while higher pressure can lead to deformation of the lamp.
Power cables must be installed with sufficient distance from the lamp. A minimum of 3 mm is recommended.
Deviations from the nominal voltage influence the lam's life, excess voltage reduces it regardingly.