Application:
An electric light source is a device that converts electric energy into light energy, widely used in daily lighting, industrial and agricultural production, national defense, scientific research, etc. Human began research on electric light source at the end of eighteenth century. Today, the electric light source has entered a new era of miniaturization, energy saving and electronic.
Classification of electric light source:
- Incoherent light source: generally can be divided into two categories: lighting source and radiation source. The lighting source is for the purpose of lighting, radiating the human eye visual electric light source (wavelength 380 ~ 780 nm). Radiation source is not for the purpose of lighting, radiating large amounts of electric light source with ultraviolet spectra (1 ~ 380 nm) and infrared spectroscopy (780 ~ 1 x 106 nm), which composes a ultraviolet light, infrared light source and non illuminated with visible light.
- Coherent light source: it emits light by the excited state stimulated particles, the output wavelength of light ranges from the short wavelength ultraviolet to far infrared, this kind of light source is called laser light source.
Light emitting method for electric light source:
- Resistance luminescence: This is a method that uses the inherent resistance of the conductor itself to generate heat effect, and then to glow, such as the commonly used incandescent lamps, iodine tungsten lamp etc.
- Arc light emission: This is a method of generating high heat arc by using two electrodes, such as carbon arc lamp.
- Glowing gas: This is a method of inputting rarefied gas and metal vapor into the transparent glass tube, using diode discharge for gas heat and light emitting, such as sodium lamp, dysprosium lamp etc.
- Phosphors lighting: This is a method of inputting rarefied gas and metal vapor into the transparent glass tube, the glass tube wall is then coated with a layer of fluorescent powder, uses gas luminescence effect of diode discharge, the fluorescent powder will absorb and send another optic, such as fluorescent lamps etc.
Material Selection:
The fine grain tungsten produced by powder metallurgy can simplify the machining process and obtain better mechanical properties. Tungsten powder doped with potassium, aluminum, silicon and thorium oxide, can improve the anti sagging performance at high temperature and reduce the electronic work function, which is applied to the high load cathode material. The tungsten doped with 1% content of thorium oxide can be drawn into a cathode blank with a diameter less than 0.25mm. Doping more content can be used for a larger diameter of the rod material.
Materials can be supplied (size, specification):
The fine grain tungsten used in the anode can be provided from 15mm to 100mm and even larger in diameter.
The tungsten doped with 1% content of thorium oxide can be drawn into a cathode blank with a diameter less than 0.25mm. Doping more content can be used for a larger diameter of the rod material.