Light source of metallographic microscope and cleaning helper of metallographic microscope
Many customers are no strangers to metallographic microscopes, but they know very little about the light sources of metallographic microscopes. Let's learn about the four light sources of metallographic microscopes with the editor.
The light sources of metallographic microscopes usually use tungsten filament incandescent lamps, halogen lamps, carbon arc lamps and xenon lamps.
(1) Tungsten filament incandescent lamp
Generally, small and medium-sized microscopes are equipped with low-voltage tungsten lamps. This kind of lamp is suitable for observation of metallographic structures.
(2) Halogen lamp (tungsten halogen lamp)
At present, the low-voltage incandescent tungsten lamps used for observation in metallographic microscopes have gradually been replaced by halogen lamps. This is because when the tungsten filament in an ordinary light bulb emits incandescence, the tungsten on the surface will evaporate, diffuse and accumulate on the light bulb, causing the light bulb to turn black and reduce the lighting brightness. At the same time, the filament will gradually become thinner and even break. If a small amount of iodine is added to the bulb through the so-called "iodine-tungsten cycle", the above defects can be effectively avoided. Its principle is: iodine molecules decompose into iodine (I) near the high-temperature filament. The iodine atoms and the tungsten on the bulb wall can combine within a certain range to form volatile tungsten iodide (WI). Once the tungsten iodide diffuses to The high-temperature tungsten filament will decompose and precipitate on the filament. Obviously, such a cycle can prevent the bulb from turning black and extend the service life of the bulb. The bulb of the tungsten halogen lamp must be made of high temperature resistant quartz glass.
(3) Carbon arc lamp
The carbon arc lamp uses two carbon rods exposed to the air and close to each other. After being energized, a strong arc is generated to emit high-brightness light. Generally, AC power supply is used, but this will cause arc flashing and unstable light source, which is especially unfavorable for photography. This is its main shortcoming.
(4)Xenon lamp
The xenon lamp is a quartz glass tube equipped with a tungsten electrode and filled with high-voltage xenon gas, which uses discharge to emit light. It is characterized by high light intensity, stable output and long life. In addition, xenon lamps have a continuous spectrum similar to sunlight and can be used for color photography. Xenon lamp is one of the new light sources for metallographic microscopic observation.
Tips: Xenon lamps are prone to explosion, so pay special attention to safety when using xenon lamps. Wear protective glasses or masks and protective gloves when installing or replacing xenon lamps. The use time should not exceed the specified time at most. When using a new xenon lamp, the oil on the quartz surface should be wiped clean with alcohol before starting. After the xenon lamp is turned off, it must cool down before it can be turned on again. Minimizing the number of starts can significantly extend the life of your xenon lamp.
In addition, the cleaning of metallographic microscopes is often a problem that worries many people, because the cleaning of metallographic microscopes will affect the detection results, but cleaning of metallographic microscopes is not easy. Let's talk about a good helper that plays an important role in cleaning metallographic microscopes-dust covers.
It is recommended that you use a dust cover, which will help keep your microscope clean and dust-free. The dust cover can isolate the microscope from contact with dust when the metallographic microscope is not in use.
1. For the lens to be cleaned, use non-solvent special cleaning fluid to clean the optical lens.
2. Use a soft brush or compressed air to remove dust and tool microscope. Then moisten a piece of dry, lint-free paper towel or lens tissue and clean the lens surface by wiping it clean in a circular motion.
3. Repeat using dry lens paper again until the lens is clean and dry. The same process is used for eyepieces and objectives.
4. To clean the inside of the lens, use a bulb flow dust collector or a compressed gas tank designed for other optical instruments.
