home > news

why does the uv lamp turn black? 6 reasons to solve the problem for you from the root! -爱游戏app官方

2019-5-29 10,258
in the process of using the ultraviolet sterilizer, the following similar situations may sometimes be encountered. the ultraviolet lamp is normal before use, but part of it turns black after use. is it because the tube has quality problems? or an operating error? why does the uv lamp turn black? will the sterilization efficiency be affected after it turns black? todon’t worry, the main reason for the blackening of the uv lamp has been sorted out for you, and the root cause can be better solved! 

1. the new lamp tube is black, and the lamp tube contains debris?

ultraviolet lamps commonly used in ultraviolet sterilizers are made by using mercury vapor pressure to mix gas with various other dissimilar metals and placing them in a vacuum glass cavity. the lamp tube contains an indispensable element: mercury. before the mercury is completely evaporated, its shape is stored in the lamp tube in the form of particles. other metals will also attach to the tube wall like dirt, which will appear particularly clear in some transparent tubes. but don’t worry, this is generally normal.


2. black at the beginning

the new lamp tube of the ultraviolet sterilizer or some lamps that have not been used for a long time, once the lamp is turned on, there will be a cloud of black gas in the filament part. is this a bad rhythm? of course not. this black gas is actually mercury vapor. the mercury gathered around the filament begins to evaporate when heated, and volatilizes upwards along the tube wall. the color becomes lighter and lighter, and finally disappears.

of course, not every lamp is like this, because not every lamp’s mercury happens to gather around the filament, which is a normal phenomenon unique to new lamps.


3. the lamp turns black after turning off the light

after the uv sterilizer lamp is off, mercury will condense due to cooling, which has the characteristic of gathering at the coldest end of the lamp. therefore, in the coldest part of the lamp, or near the air conditioner, there are often mercury pollution traces left by repeated evaporation and condensation of mercury. this is a normal phenomenon.

4. cold end black spots

after a short-term use of the uv sterilizer lamp, a black spot on the side of the filament is often seen, and it will become larger and larger as the use time extends. the reason is that the lamp tube is getting thinner and thinner, the power is getting bigger and bigger, the filament is getting longer and longer, and the filament electrode gets closer and closer to the tube wall. in each preheating of the lamp, if the ion bombardment is too large, it is easy to there are several reasons for the black spots attached to the pipe wall:
  • the power supply error is too large during use.
  • too many frequent switches.
  • the starting voltage is too high or the preheating time is incorrect, and there are too many flashes.
  • the preheating current of the ballast is too large.
  • the starting voltage is too high or the preheating time of the electronic ballast is insufficient.

5. black circles like rings

after long-term use of the uv sterilizer tube, the metal halide bulb has a black ring around the filament. this is because each time the lamp is turned on, the ions produced by the cathode are relatively heavy, and the caused by the tube wall, this is a natural phenomenon and has nothing to do with the life of the tube and the light effect.


6. cause discoloration of the pipe wall

in the production process, if the heating and baking and exhausting and vacuuming processes are not perfect, hydrogen will remain, which will also be combined with mercury to deteriorate and pollute the fluorescent lamp powder. if a new tube occurs immediately, it is a defective lamp. tube-(yellow and black). in addition, the soda lime glass or high-lead glass used to make the lamp tube contains a large amount of sodium. during the lighting process, sodium will precipitate from the glass tube, combine with mercury, and become sodium amalgam, which is deposited in the fluorescent lamp powder layer, resulting in fluorescent lamps powder spoiled.

in summary, there are many reasons for the blackening of the ultraviolet sterilizer lamp, but most of them will not affect the normal use of the lamp.

of course, the safest way is to install an ultraviolet intensity monitor to help us grasp the working conditions of the ultraviolet lamp.


爱游戏app官方-爱游戏app官网入口 vision: by focusing on the continuous development of products and services to guide customer needs, become a professional company recognized by global users.
爱游戏app官方-爱游戏app官网入口 mission: establish a highly competitive technology company through a unique culture, provide customers with excellent products, and enable them to establish a deep relationship with the company.
this article is renownuv’s original article, please attach the source for reprinting:爱游戏app官方-爱游戏app官网入口

a professional brand focused on offering complete proposals of air and water cleaning, has advanced purification compounding technology of photochemical reaction and photophysics process and design capability from europe.
about us
about us