The National Technical Code for Disinfection (2002 Edition) stipulates that：

3.1.4 UV disinfection

3.1.4.1 Scope of application: Used for disinfection of indoor air, object surfaces, water, and other liquids.

3.1.4.2 UV disinfection lamp and UV sterilizer

(1) The UV used for disinfection is C-wave UV, with a wavelength range of 200nm~275nm, which has the strongest bactericidal effect

The wavelength range is 250nm~270nm, and the ultraviolet light source used for disinfection must be able to produce sterilization ultraviolet radiation with an irradiation value that meets national standards

Line lights.

(2) To prepare UV disinfection lamps, grade grade grade quartz glass tubes should be used to obtain satisfactory UV irradiation intensity.

(3) UV disinfection lamps can be equipped with reflective covers made of materials with high UV reflection coefficient, such as polished aluminum plates

(4) UV lamps for disinfection are required to operate at a voltage of 220V, an ambient relative humidity of 60%, and a temperature of 20 ℃,

The intensity of 253.7nm ultraviolet radiation (in use intensity) shall not be less than 70 μ  W/cm 2 (regular 30W straight tube ultraviolet lamp

It is measured at a distance of 1 m from the lamp tube, and the special violet outer line lamp is measured at a distance of use, and the violet outer line strength meter used must be calibrated.

During the period of validity; The UV intensity monitoring indicator card used should be obtained from the health permit and used within the validity)。

 (5) During the use of ultraviolet lamps, their radiation intensity gradually decreases, so the intensity of disinfected ultraviolet rays should be regularly measured. Once the intensity decreases

When the required strength is below, it should be replaced in a timely manner

.

(6) The service life of ultraviolet disinfection lamps is reduced from the intensity of the new lamp to 70 μ  Time of W/cm 2 (power ≥ 30W),

The time to reduce to 70% of the original new lamp intensity (power<30W) should not be less than 1000h. UV lamp production units should

Provide actual service life.

(7) Currently, there are several types of ultraviolet disinfection lamps used in China:

1) Ordinary straight tube hot cathode low-pressure mercury ultraviolet disinfection lamp: The lamp tube is made of quartz glass or other materials with high ultraviolet transmittance

Made of glass, with powers of 40W, 30W, 20W, 15W, etc. Require the intensity of 253.7nm ultraviolet radiation from the factory's new lamp (within

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Measured at a distance of 1m, without reflector, for lamps with a power greater than 30W, ≥ 90 μ  W/cm 2; Power>20W lamp, ≥ 60 μ

W/cm 2; 15W lamp, ≥ 20 μ  W/cm 2. Due to the fact that this type of lamp not only radiates 253.7nm ultraviolet radiation, but also emits

Emitting a portion of 184.9nm ultraviolet light can generate ozone.

2) High intensity ultraviolet disinfection lamp: requires an intensity of 253.7nm ultraviolet radiation (at a vertical distance of 1m from the center of the lamp tube

Measured as: 30W lamp,>170 μ W/cm 2; 11W light,>40 μ W/cm 2.

3) Low ozone ultraviolet disinfection lamp: It is also a hot cathode low-pressure mercury lamp, which can be a straight tube or H-type, due to the use of special

Due to the process and lamp material, the ozone production is very low, requiring an ozone production rate of<1mg/h.

4) High ozone ultraviolet disinfection lamp: Due to the adoption of a special process, this lamp produces a large proportion of wavelengths of 184.9nm

Ultraviolet radiation leads to a higher production of ozone.

(8) UV sterilizer:

1) Ultraviolet air dis infector: manufactured with low ozone ultraviolet sterilization lamp, it can be used for indoor air disinfection under human conditions

Poison.

2) UV surface sterilizer: manufactured with low ozone and high intensity UV sterilization lamps to quickly achieve satisfactory results

Disinfection effect.

3) UV disinfection box: Made with high ozone high intensity UV sterilization lamp or straight tube high ozone UV lamp, on the one hand

Utilize the synergistic bactericidal effect of ultraviolet and ozone, and on the other hand, use ozone to disinfect areas that cannot be irradiated by ultraviolet radiation.

3.1.4.3 Scope and conditions of application

(1) Ultraviolet radiation can kill various microorganisms, including bacterial pro pagules, spores, micro bacteria, viruses, fungi, and Ricketamine

Any surface, water, and air contaminated by the aforementioned microorganisms, such as secondary organisms and micro plasma, can be disinfected using ultraviolet radiation.

(2) Ultraviolet radiation has low energy and weak penetration, and can only kill directly irradiated microorganisms. Therefore, it is necessary to disinfect

The toxic parts are fully exposed to ultraviolet radiation.

(3) When disinfecting rough surfaces such as paper and fabric with ultraviolet radiation, the exposure time should be appropriately extended, and both sides should be exposed to radiation.

(4) The suitable temperature range for ultraviolet disinfection is 20 ℃ to 40 ℃. If the temperature is too high or too low, it will affect the disinfection effect

When extending the disinfection time for air disinfection, it is better to have a relative humidity of less than 80% in the disinfection environment, otherwise it should be appropriately extended

Shooting time.

(5) When using ultraviolet radiation to kill microorganisms protected by organic matter, the irradiation dose should be increased. The suspended particles in air and water are also

It can affect the disinfection effect.

3.1.4.4 Usage

(1) Disinfection of the surface of items:

1) Exposure method: It is best to use a portable ultraviolet sterilizer for close range mobile irradiation, or use a UV lamp suspension for illumination

Shoot. Small items can be placed in a UV disinfection box for irradiation.

2) Exposure dose and time: Different types of microorganisms have different sensitivity to ultraviolet radiation, and when using ultraviolet radiation for disinfection, it is necessary to

The irradiation dose required to kill the target microorganisms is achieved using the irradiation dose.

When killing general bacterial propagules, the irradiation dose should reach 10000 μ W. S/cm 2; When killing bacterial spores, it should reach 100

000 μ W. S/cm 2; The resistance of viruses to ultraviolet radiation is between bacterial propagules and spores; Fungal spores have a stronger resistance than bacteria

The spores are stronger and sometimes require irradiation up to 600000 μ W. S/cm 2, but generally pathogenic fungi have more resistance to ultraviolet radiation than bacterial buds

Cellular weakness; When the target microorganisms for disinfection are unknown, the irradiation dose should not be less than 100000 μ W. S/cm 2. The irradiation dose is the product of the irradiation intensity and irradiation time of the ultraviolet lamp used at the surface of the irradiated object. Therefore, based on the irradiation intensity of the ultraviolet light source, the time required for irradiation can be calculated. For example, using an irradiation intensity of 70 μ A W/cm 2 ultraviolet surface disinfector is used to irradiate the surface of an object at close range, with a selected irradiation dose of 100000 μ W. S/cm 2, then the required irradiation time is:

100 000 μ W. S/cm 2 ÷ 70 μ W/cm 2=1429 s ÷ 60s Å 24 min.

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(2) Disinfection of indoor air:

1) Indirect irradiation method: High intensity ultraviolet air disinfector is preferred, which not only has a reliable disinfection effect but also can be used indoors with people

For use during activities, it is generally recommended to turn on the machine and disinfect for 30 minutes to achieve qualified disinfection.

2) Direct irradiation method: Under unmanned indoor conditions, ultraviolet lamp suspension or mobile direct irradiation can be used. Adoption room

When using internal suspended UV disinfection, install a UV disinfection lamp indoors (30W UV lamp with an intensity of>70 at 1.0m) μ W/cm 2)

The average quantity is not less than 1.5W per m3, and the irradiation time is not less than 30min.

(3) the disinfection of water and other liquids can be irradiated in or out of water, and ultraviolet light source can be used in the method of internal irradiation in water.

Quartz glass protective cover should be installed, no matter what method is taken, the thickness of the water layer should be less than 2cm, according to the intensity of the ultraviolet light source

Determine the speed of the current. After disinfection, the water must meet the national standards.

3.1.4.5 Precautions

(1) During use, the surface of the UV lamp should be kept clean, usually wiped with an alcohol cotton ball every two weeks

When there is dust or oil on the surface of the lamp tube, it should be wiped at any time.

(2) When disinfecting indoor air with ultraviolet lamps, the room should be kept clean and dry to reduce dust and water mist, and the temperature should be below 20 ℃

When the temperature is above 40 ℃ and the relative humidity is greater than 60%, the exposure time should be appropriately extended.

(3) When disinfecting the surface of items with ultraviolet radiation, the irradiated surface should be directly exposed to ultraviolet radiation and sufficient illumination should be achieved

Radiation dose.

(4) Do not expose ultraviolet light sources to people to avoid damage.

(5) The UV intensity meter should be calibrated at least once a year.