The best raw materials is borosilicate 3.3 glass, light the glass, high strength, raw material is by the ton in, some manufacturers from the raw material is not qualified, the poor and glass wall thin glass. The first is fragile, light is not good, and nonvolatile vacuum. To distinguish weighs on the line as long as. Heavy, of course, good raw materials.
Coating is the core technology of vacuum tube, the real complete master of the company is not much. The influence of the color is not very big, but the issue of beauty. Good coating is better than the absorption and emission ratio, do not just look at the absorption.
Vacuum degree is the effect of heat preservation, good vacuum tube to 200 degrees high temperature pumping more than 1 hours, in order to ensure that the air in the interlayer of the air and the discharge of the gas. Some manufacturers heating temperature low time is short, so you can save a lot of money. Identification method is in the sun is good when air drying tube and with the outer wall of the hand grip, if the temperature and vacuum degree is certainly not is very good cold vacuum and long service life.