The principle of germicidal disinfection by ultraviolet light: The principle of germicidal disinfection by ultraviolet light photons is to use the energy of ultraviolet light to break the DNA structure of various viruses, bacteria and other pathogens in the water body. The main purpose is to make various structural bonds in DNA break or photochemical polymerization reaction, such as making DNA thymine dimer, so that various viruses, bacteria and other pathogens lose the ability to replicate and reproduce, to achieve the effect of sterilization.
How to use the UV lamp
1. Scope of application: For disinfection of indoor air, object surfaces and water and other liquids.
2. Use methods.
(1) Disinfection of indoor air.
a) Indirect irradiation method: preferred high-intensity ultraviolet air disinfection, not only reliable disinfection effect, and can be used when indoor activities, generally disinfection lamp on 30min can reach disinfection qualified. The lamp is less than 2m from the working floor.
b) Direct irradiation method: Under unoccupied indoor conditions, UV lamps can be suspended or mobile direct irradiation. When using indoor suspended UV disinfection, the number of UV disinfection lamps (30W UV lamp, intensity >70μW/cm2 at 1.0m) installed indoors is not less than 1.5W per m3 on average, and the irradiation time is not less than 30min.
(2) disinfection of the surface of the item: the best use of portable ultraviolet disinfector close mobile irradiation, but also can take the UV lamp suspended irradiation. For small items can be placed in the UV disinfection box irradiation. Specific requirements: lamp distance from the surface of the object shall not exceed 1 m, should use the irradiated surface is subject to direct irradiation, and should achieve sufficient irradiation dose (to kill bacterial spores should reach 100000μWs/cm2).
a) During use, the surface of the UV lamp should be kept clean and generally wiped with an alcohol cotton ball once a week.
b) When disinfecting indoor air with UV lamps, the room should be kept clean and dry to reduce dust and water mist.
c) When disinfecting the surface of articles with UV light tube light, the irradiated surface should be exposed to direct UV light and should reach a sufficient dose of exposure.
d) When using UV direct irradiation for disinfection, people should not be in the room. The UV light source should not be irradiated to people to avoid damage.
e) Make good records of use and measure the radiation intensity once every six months, and have records.
f) Kindergartens use UV lamps to isolate people for disinfection for 30 minutes, and let the air circulate for 30 minutes after disinfection is safe and effective.
4. Personal protection for operators.
In the absence of protective measures, short-wave UV radiation can cause direct harm to
1) Human eyes and skin exposed to ultraviolet light lines can not exceed 3 minutes.
2) If the direct exposure after 15 minutes, it will cause corneal damage leading to electrophthalmic uveitis, sudden severe pain in both eyes, foreign body sensation, photophobia, tearing or eyelid spasm, etc.
3) Long-term exposure can damage the eyes and skin, leading to eye trauma and severe skin burns, and may lead to skin cancer. Must require UV lamp disinfection operators must wear protective equipment, such as the use of multifunctional protective glasses for eye protection, must not be directly irradiated; should also avoid skin contact with ultraviolet radiation. When UV disinfection is carried out in public places, extraneous persons should be avoided, especially to prevent the elderly and children from entering the UV lamp work area by mistake.