Ultraviolet Germicidal Irradiation Uvgi Biology Essay

Ultraviolet bactericidal irradiation is the usage of ultraviolet energy electromagnetic radiation with a wavelength shorter than that of seeable visible radiation to kill or demobilize viral, bacterial, and fungous species. The UV spectrum is normally divided into UVA ( wavelengths of 400 nanometers to 315 nanometer ) , UVB ( 315 nanometer to 280 nanometer ) , and UVC ( 280 nanometer to 200 nanometer ) . The full UV spectrum can kill or demobilize many micro-organisms, but UVC energy provides the most bactericidal consequence, with 265 nanometers being the optimal wavelength. The survey of UVGI distribution is really of import to demo the effectual of germicidal and happen out a better location for UV illuming in order to better indoor air quality.

A all-out room ( 11.9 M3 ) fitted with a UVGI system dwelling of 14 louvered irradiated the top 30 centimeter of the room ( 12 W entire lamp powers per UVC lamp ) and assumed maintained at 25C and 50 % comparative humidness. Correspondingly, there are entire 1125 points of measuring and experiments were performed in some different conditions such as, height degree, grade of the louvre, being of the louvre, coefficient of reflection and figure of fives in the louvre between the measurings. Besides the point measuring, utilizing fluorescent stuff can besides mensurate the distribution of ultraviolet irradiation. The system irradiates the upper portion of a room while minimising radiation exposure to individuals in the lower portion of the room.

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1. Introduction

1.1 Background

Presents, people are more involvement in the air quality in different environments. Particularly after the eruption of terrible acute respiratory syndrome ( SARS ) in 2003, in which more than 8000 people were infected and over 700 people died ( WHO, 11 July, 2003 ) .As Hong Kong is an international metropolis, there are many high rise edifice such as offices, shopping centres, infirmaries. Many people need to remain interior country everyday. Hence, there are a batch of people who are infected by different infective diseases through air transmittal. Therefore, the survey of air quality in different indoor environments is now interested by different research workers in Hong Kong. One of methods to better the indoor air quality is that utilizing of UV ( UV ) energy to kill or demobilize viral, bacterial, and fungous species. Hence, the survey of UV distribution can better indoor air quality in these edifices becomes more of import.

1.2 Objective

In order to forestall eruption of infective diseases such as SARS, we should hold better information about the strength of ultraviolet irradiation within upper-room country in indoor environments. It is found that indoor air quality can be controlled by the ultraviolet irradiation as UVC can kill the contaminations. As there is non many research documents for distribution of Ultraviolet irradiation at upper-room country, the intent of this study is to understand the UV strength distribution in some different conditions such as, height degree, grade of the louvre, being of the louvre, coefficient of reflection and figure of fives in the louvre between the measurements.The system irradiates the upper portion of a room while minimising radiation exposure to individuals in the lower portion of the room.

There are several specific aims:

1 ) To analyze the distribution of Ultraviolet irradiation by experimental methods.

2 ) To analyze the factors impacting Ultraviolet irradiation by experimental methods.

3 ) To analyze utilizing fluorescent stuff to mensurate the strength of Ultraviolet irradiation

2. Literature reappraisal

Literature reappraisal is done with a sum-up of literature hunt methods and the figure of documents and articles found for the readying work of this undertaking. As a drumhead, UVGI system is affected by many factors.

2.1 In-Duct UVGI

In-duct UVGI systems are installed inside airing ductwork or inside AHUs. When selected to bring forth appropriate irradiance degrees, in-duct systems are effectual for surface and air disinfection. The end of surface disinfection is to cut down or extinguish microbic growing on inA­ternal surfaces of HVAC systems, typically chilling spirals and drain pans. The end of air disinfection is “ on-the-fly ” inactivaA­tion of bugs suspended in the air as it moves through the canal or AHU.

In-duct UVGI should ever be used in combination with filtration. Filters help protect UV lamps from dust that may cut down UV end product, and enhances the air cleaning capablenesss of the system. Filters remove larger bugs like fungous spores that are more immune to UVGI, while UV inactivates more susA­ceptible beings like bacteriums and viruses. It is recommended that the highest-rated filter the fan motor can manage be used, while still supplying equal air flow to the infinite.

2.2 Upper-Air UVGI

Upper-air UVGI involves lamp fixtures suspended from the ceiling and/or installed on walls. Lamps are shielded to direct radiation upward and outward to make an intense zone of UV in the upper part of the room while minimising UV degrees in occupied infinites. These fixtures inactivate airborne micro-organisms by enlightening them as air currents travel them into the way of the UV energy. Some louvered fixA­tures use little fans to heighten air commixture, which is a critical constituent of overall effectivity.

Where an in-duct UVGI system may non be executable, or where extra UVGI is desired to further cut down airborne infective disease transmittal, upper-air systems can supply an effectual solution. Application and arrangement standards for upper-air UV fixtures are provided in assorted publications, and manufacturer-specific advice on arrangement and operations should ever be followed. A regulation of pollex for upper-air installings has been one 30 W ( nominal input ) fixture for every 200 ft2 ( 18.6 M2 ) of floor infinite to be irradiated.16 Many effectual systems have been designed to this standard, yet it is of import to observe that non all 30 W lamps provide the same end product of UVC energy. UVC end product is dependent on the type of lamp, the lamp maker, and variA­ous other factors. Recent surveies have suggested installing fixtures to keep a unvarying UV distribution of around 30 I?W/cm2 to 50 I?W/cm2 in the upper part of the room.17 While basically “ normalising ” the recommended end product over all lamps, this degree of irradiance should be effectual at demobilizing most airborne droplet karyon incorporating Mycobacterium, and would presumptively be effectual for inactivation of most viruses every bit good.

The overall effectivity of upper-air UVGI systems improves significantly when the air within the infinite is good assorted. Although convection air currents created by residents and equipment can supply equal air circulation in some scenes, mechanical airing systems that maximize air commixture are preferred. If air blending with mechanical airing is non possible, fans can be placed in the room to guarantee equal commixture.

2.3 Relative Humidity

Relative humidness ( RH ) without a important impact on the public presentation of UV lamps, and it ‘s besides impact on the susceptibleness of microorganisms is non good understood. However, Try to microorganisms associated with the sensitiveness of the RH have yielded inconsistent consequences, but it seems to be organisms specific. 18, 19

The relationship between generative wellness, and the K values seem complicated, but most of the surveies the consequence of an addition merely in the comparative humidness values above 70 % . Recommended that UVGI system operation comparative humidness less than 60 %

This is in line with the recommendations of ASHRAE and other organisations to supply a comfy, acceptable indoor air quality, decrease of indoor microbic taint. Most upper-air UVGI systems are working decently to keep comparative humidness below 60 % . On the contrary, in the air canal systems, frequently operate in high humidness degrees.

2.4 Air Temperature and Velocity

Phillips Lighting ( 1992 ) states that the resonance line at 254 nanometers in a low-pressure quicksilver lamp is strongest at a peculiar vapour force per unit area that occurs in their proprietary UVGI lamps at a still air ambient temperature of about 68 F ( 20 C ) . For their lamps, this gives a lamp wall temperature of about 104 F ( 40 C ) , and the UVGI end product is greatest at that temperature. At both higher and lower temperatures, the UVGI end product is reduced, with the end product at 50 F ( 10 C ) being about 88 % of that at 68 F ( 20 C ) . In their merchandise literature, Westinghouse ( 1985 ) concurs. They note that the end product of their UVGI lamps, like all other gaseous discharge lamps, diminishes as the temperature increases or decreases from the design temperature, which for the Westinghouse lamps is stated to be 80 F ( 27 C ) in still air. They note that the end product of one lamp at 40 F ( 5C ) is merely two-thirds of its end product at 80 F ( 27 C. )

Westinghouse ( 1985 ) besides notes that low temperatures can cut down the operating life of the lamps and that another of their proprietary lamps responds otherwise. Another lamp, when operated at its highest current input, is said to be much less sensitive to ambient temperature alterations. Phillips Lighting ( 1992 ) makes a similar statement, stating that their medium-pressure quicksilver lamp, comparative to the low-pressure lamp, has a higher power denseness and higher wall temperature and is less sensitive to ambient temperature fluctuations. High lamp end product at the lower temperatures encountered in canals is a cardinal statement for the ” high end product UVGI emitter ” presented by Scheir and Fencl ( 1998 ) . Westinghouse ( 1985 ) further notes that low runing temperatures cut down the operating life of their lamps

The consequence of air flow on UVGI lamp end product is increased heat transportation that is due to the traveling air. If the air traveling past the lamp is ambient or cool, the lamp may be cooled below its optimal operating point, which reduces end product. If the air is warm, the lamp may be heated above its optimum, which besides reduces end product. Lamps in the return air of edifice airing systems are likely to be somewhat cooled below their optimal temperature, while lamps downstream of a chilling spiral could be well cooled due to a combination of airflow and low temperature. Lamps designed for operation at low temperatures should besides be immune to airflow effects.

Air temperature and speed by and large do non impact microorA­ganism susceptibleness to UVGI. However, their combined consequence on lamp temperature can do important fluctuation in lamp end product, and finally UV dosage. Depending on the lamp used, the UV end product for in-duct systems can change by more than 60 % across a scope of temperature and speed conditions typical of HVAC system operation, peculiarly in VAV systems where both can alter simultaneously.20 Modern UVC lamps are designed to cut down the end product fluctuation experienced by lamps designed to run at room temperatures and still-air conditions when they are used for in-duct applications. The impact of air temperature and speed should be considered in the design of in-duct sysA­tems to guarantee that coveted public presentation is maintained across all operating conditions. Output fluctuation due to air temperature and speed is non a concern for most upper-air systems.

2.5 Coefficient of reflection

In the air canal system, increasing the effectivity of UV is one of benefit of brooding tunnel. Contemplation can be an economical manner to increase the strength of UV because of the reflected energy increases the energy. Although the surface may reflect the seeable visible radiation, it may non reflect the UV light energy. For illustration, polished brass reflects the most of seeable visible radiation, but less than 10 % of ultraviolet radiation. Galvanized pipe stuff has UV coefficient of reflection rate of about 55 % . Aluminum and other brooding stuffs can be used to line pipes in order to better the effectual UV strength degrees. System interior decorators and makers can supply information on bettering the contemplation of UV in air canal applications. Reflectivity besides may be a concern about the upper-air system. For the properly designed, upper-air system installings indispensable for the remotion from the ceiling or against a wall in the UV coefficient of reflection found that more than 10 pess ( 3 metres ) from the lamp.

3. Methodology

3.1 Stainless Steel Chamber

The chromium steel steel chamber is made as a scaly chamber for the experiment of the Ultraviolet illuming systems. The scale ratio of the chamber is a full graduated table room for step the irradiance green goods by different instance of UVC lamp. In order to guarantee the quality of insularity of the chamber, it is made by utilizing unstained steel by the connexion of welding. A UVGI system is installed in the center of the full graduated table room and mounted in the overhead place 196cm above the land surface by wire and plastic belt. The wire is mounted on the two border of the wall by nail. This ensures the full unity of the wall surface. The plastic belt is used to keep the louvres as the weight of the louvres is really heavy. There are great fondnesss of the balance of the UVC visible radiation if we do non utilize the plastic belt. Furthermore, there are two air diffusors and one T5 lamp is installed on the ceiling of the room. There are 5 surface of the room is make of chromium steel steel. The staying side of wall which the door located is cover by canal tape.

3.2 Measurement Position at the Chamber

3.2.1 First measuring place

For the first measuring place, mean 5 ten 5 points is set up. However, there are some troubles for the equipments to mensurate the reading due to the country from the wall. Besides, the side walls constrained the measurement place.

3.2.2 Second measuring place

Due to the above ground, a new measuring place is set up. These measurement places converge to the lighting since there is a big UV strength difference. It can easy input the information for the simulation and increase the truth for the changing of UV strength.

3.3 Method of measuring

3.3.1 Preparation Work

1. Background of the room

There are some readying work demands to be done before we began to mensurate UV strength in different state of affairss in different conditions. First, we must turn out that the unity of the original environment of room. First, we need to look into the dark room conditions. Because we use double-sided pat adhere to the surface of the black paper in the room. There are some losingss after we measure a set of informations. After a period of clip, we use an excess high-quality double-sided pat solved this question. Although the issue has been resolved, but we still need to look into the position of the black paper before the start the experiment of every clip we test.

2. Position and degree of the UVC visible radiation

The position and degree of ultraviolet light demand to set every clip due to the heavy weight of the louvre that impacting the tenseness between the shutters and plastic tape. Therefore, we need to look into their place by the ultra-infrared detectors to guarantee the place right.

3. Angle of the louvre

As the heavyweight louvre, the nail of louvre can non repair the angle as a immense force per unit area on it. Therefore, the angle between the UVC visible radiation and louvre is varied due to a long clip period. We need to guarantee the accurate angle from the protractor, and so get down the experiment.

4. Calibration of the UV metre

The UV metre demands to put 0 Numberss at no UV irradiance status before utilizing in the room measuring. We were informed about the importance of taking careful and patient measurings.

5. Use of filter

The detector is necessary to put in with 2 type of filter that can mensurate the UVC 254nm wavelength irradiance. In the early clip, we have missed the use of the filter. Therefore, the reading of the UV metre we measured is about 10 times of the true UVC wavelength irradiance. It needs to pay much attending on this.

3.3.2 Procedures

The centre UVGI system is operated at full power, 12 W. The UVGI system is warmed up for 30 proceedingss before changeless irradiance reading occurred, after that the experiments were conducted. Cosine-response UV-meter is used to qualify the UVC distribution in the room. To mensurate the irradiance in the upper zone of the room.UV-meter were positioned at 45 planed separated points of different height degree from the floor. The UV metre is positioned by the tripod with three every bit height chairs. The UV metre is need to tune its tallness to different tallness by rise or decrease the tripod ‘s tallness. The tallness of tripod is measured by metre. Then, positioning the UV metre in one of 45 points marked on the land by metal plumb bob.

1. Black Paper Measurement

1. The UV lighting is confirmed horizontal by the horizontal metre

2. The tallness of detector is confirmed by the metre.

3. The irradiance reading is take topographic point on the tallness of 200cm, 205cm and 210cm at 0 degree measuring.

3. The UV lighting is switched on and warmed up for 30 proceedingss

4. The UV detector is ensured that confronting the UV illuming straight and the metal plumb bob is indicated the points for measuring right.

5. The UV strength is recoded from the UV metre for each measurement point

6. The measurement points are measured repetition for the tallness of 200cm, 205cm and 210cm and the weak lighting measuring for 205cm.

7. No airing was provided in this instance during this period and the UVGI lamps were kept on.

8. We need to reiterate the measuring until the reading of the points is symmetrical between A, B, C, D column ‘s side and F, G, H, I column ‘s side.

9. The 5 degree measuring for 205cm, 210cm and 215cm are repeated to mensurate.

10. After step the high end product lighting, the low end product lighting is besides measured at 205cm.

2. without Black Paper Measurement

1. The black paper is removed.

2. Repeating the same processs for Black Paper Measurement.

3. The irradiance reading is take topographic point on the tallness of 200cm, 205cm and 210cm at 0 degree measuring.

4. The irradiance reading of 205cm, 210cm and 215cm were measured at 5 grade.

5. There are airing supply by the diffusor and the escape supply outside of the room.

3. Upward Measurement

1. The UV lighting is confirmed horizontal by the horizontal metre

2. The tallness of detector is confirmed by the metre and no louvre is included in this instance.

3. The UV lighting is switched on and warmed up for 30 proceedingss

4. The UV detector is ensured that confronting upward to the ceiling and the metal plumb bob is indicated the points for measuring right.

5. The UV strength is recoded from the UV metre for each measurement point.

6. The measurement points are measured for 1 lamp and 2 lamps at 200cm.

4. New Louver

1. There is no black paper included.

2. The UV lighting is confirmed horizontal by the horizontal metre 5 and the louvre is tuned to horizontal 0 grade.

3. The tallness of detector is confirmed by the metre.

4. The UV lighting is switched on and warmed up for 30 proceedingss

5. The UV detector is ensured that confronting the UV illuming straight and the metal plumb bob is indicated the points for measuring right.

6. The UV strength is recoded from the UV metre for each measurement point

7. The measurement points are measured repetition once more for all fives, 7fins and 4 fives.

8. The 5 degree measuring for all fives, 7fins and 4 fives is repeated to mensurate.

3.4 Application of LabVIEW with Grayscale pel

3.4.1 Application of LabVIEW

At first, we use LabVIEW 7 as a platform for the connexion of the web camera. The first measure we need to make is that commanding the web camera in the computing machine. To make this application, it needs to put in the NI-IMAQ for USB Cameras which this plan can build the sub-VI for connect between the computing machine and the web camera. Besides the NI-IMAQ for USB Cameras, it besides needs to put in the plan which is Vision 8.5.0 Development Module. For this plan, it is most of import since this plan is used for image processing.

After the connexion between the computing machine and the web camera, it needs to capture the image from the web camera. The images have different pel and it can demo the value of pel from the plan of LabVIEW.

The above diagram is the VI block diagram for demoing the value of pel from the plan of LabVIEW. The VI block diagram is combined by two parts. The first portion is the connexion of the camera. After go throughing though the first portion of the camera, it will split to another portion which is IMAQ Image To Array. The map of this portion is used to observe the income image pel.

3.4.2 Grayscale pels

Grayscale images are frequently the consequence of mensurating the strength of visible radiation at each pel in a individual set of the electromagnetic moving ridge spectrum such as infrared, seeable visible radiation, UV, etc. The Grayscale images can be combined from a full colour image. In the instance of transmitted, the brightness degrees of the ruddy ( R ) , green ( G ) and bluish ( B ) constituents are each represented as a denary figure from 0 to 255, or binary 00000000 to 11111111. For every pel in a red-green-blue ( RGB ) grayscale image, R = G = B. The elation of the grey is straight relative to the figure stand foring the brightness degrees of the primary colourss. White is represented by R = G = B = 255 or R = G = B = 11111111 and black is represented by R = G = B = 0 or R = G = B = 00000000, and. Since there is 8 spot s in the binary representation of the grey degree, this imaging method is called 8-bit grayscale. As with 8-bit grayscale, the elation of the grey coloring material is straight relative to the figure of stand foring the brightness degrees of the primary colourss.

3.4.3 Procedures

1. The UV lighting is confirmed horizontal by the horizontal metre

2. The tallness of fluorescent home base is confirmed by the metre.

3. The UV lighting is switched on and warmed up for 15 proceedingss

4. The fluorescent home base is ensured that confronting the UV illuming straight and the metal plumb bob is indicated the points for measuring right.

5. The UV strength is recoded from the LabVIEW.

3.5 Equipments

3.5.1 UV Lamps and Ballasts

Both were 36.8m long, T5 ( 0.73 centimeter diameter ) . The ballasts were connected to the lamps through three-pin power connections. Power was provided to the terminal of lamp by wires running from power connection through the hole in the corner merely above the land outside of the room. Both high end product lamps agreement is the same, there is reflector behind the lamp to reflect and louvres to lend the UVC beam discharge horizontal from the lamp. Their end product is the same as mention informations provided by provider. They are 12W low quicksilver lamp but their UVC end product is non the same due to associate to the different working life of them and different angle of the reflector which located inside the lamps. Because the industry does non utilize a standard trial or mention method to mensurate UVGI lamp end product presented in the sample proficient paper. Hence, the trial of lamps is through direct measuring. The two trial lamps were indistinguishable visually except the UVC end product is different. The two lamps end product are measured by UV-meter before the experiment start and shown below

In our experiment, we chiefly focus on the high end product lamp.

3.5.2 UV metre ILT1400

Broadband UVC measurings require a two measure zeroing procedure. The SEL240/TD measures both UVB ( 280 to 315 nanometers ) and UVC ( 200 to 280 nanometers ) wavelength light. The SEL240/UVB1/TD combination adds a crisp cut filter ( UVB1 ) to mensurate merely UVB. The SEL240/TD can be used entirely in a individual measure measuring for most genera cubic decimeter purpose Ultraviolet applications.

3.5.3 UV detector and Tripod

UV detector is used to observe UV irradiance. To divide the UVA, UVB and UVC constituents, it needs to put in the filter in forepart of the detector. All ILT1400 sensors attach to the card border at the top of the ILT1400 metre. The “ L ” listed in the sensor theoretical account figure signifies the usage of the sensor card border connection required for connexion to the ILT1400 Meter ( Internet Explorer. SEL, XRL, SPL ) .The sensor card border connections have been carefully designed so that sensors and extension overseas telegrams can be plugged onto the card border both frontward and backward.

The SEL240 254 base sensor contains a specially coated 0.33 cm2 UV stabilized Si cell with a vitreous silica window. The SEL033 is one of our most normally used detectors. It can be used with a big mixture of filters, input optics and standardizations and covering the wide spectrum of 200 – 1100 nanometer.

3.5.4 UV Lighting and Original Louver

The louvre is used to cut down and centralise UV irradiance. The UV lighting is equipped with homocentric 14 black louvres of 0.7 centimeter spacing. The tallness of the louvre is about 11 centimeters and they were installed so that the lower border was located 1.96 m above the floor and the top was 14.5 centimeter below the ceiling. This agreement discharges a set of UVGI in the upper degree of the room, with an mean deepness of about 20 centimeter. The deepness of the set is different throughout the room, the narrowest distance being closest to the lamps at 15 centimeter and the widest discharge tallness is about 20cm.

3.5.5 New Louver

As the fives inside the original louvre is fixed, a new louvre is designed which can take the fives inside the louvre.

3.5.6 Metal plumb bob

The metal plumb bob connected to the centre of Tripod. The map of the metal plumb bob was a arrow to bespeak the point for measuring.

3.5.7 Fluorescent Material

In order to reflect the value of UV which was emitted from the UV lighting, the fluorescent stuffs are applied.

In the instance of dark room state of affairss, the irradiance of three different degree 200cm, 205cm and 210cm are measured. The consequences of the UV metre measurings for the UVGI lamps runing are presented in the above figure. The above contour shows 0 degree louvre with high end product illuming trial. For the horizontal degree with UV illuming which is 205cm, the UV irradiance extremum in the part closest to the leading lights and the country along the diagonals of the room. In the instance of 205cm, there are two set of measuring with different UV visible radiation. For the strong visible radiation, the highest value of 205cm was 432AµW/cm2. For low end product lighting, the maximal value is 381I?W/cm2 and the lower limit is 2.4I?W/cm2. The UV irradiance value lessening far off from the lamp in the instance of 205cm. At 200cm, it shows that the UV irradiance value is low but addition far off from the lamp and all readings is about 30AµW/cm2. The maximal value is 45.2I?W/cm2 and the lower limit is 0.5I?W/cm2. There is same instance occurred at 210cm but the UV irradiance value is lower than the readings of 200cm and all the readings is lower than 3AµW/cm2. The maximal value is 2.9I?W /cm2 and the lower limit is 0.61I?W /cm2. Besides, all the reading in this set measuring informations is symmetrical.

The UV irradiance with UV lamps runing at 5 degree upward is besides measured. At horizontal degree of the louvre, the UV irradiance readings at 205cm are the largest value. However, when the UV lamps operate at 5 degree upward of the louvre, the UV irradiance is shifted from 205cm to 210cm. In the instance of 205cm, there are two set of measuring with different UV visible radiation. For the instance of 205cm of high end product illuming at 5 grade, the maximal value is 375I?W/cm2 and the lower limit is 0.42I?W/cm2. For the low end product lighting, the maximal value is 259I?W/cm2 and the lower limit is 0.42I?W/cm2.Besides, it shows that the UV irradiance lessening at 205cm and 210cm severally. Furthermore, the above contour shows that the value of UV irradiance addition at the back side at 215cm. However, in the instance of 215cm, the maximal value is 30I?W/cm2 and the lower limit is 0.1I?W/cm2.Besides, all the reading in this set reading is symmetrical. Hence, it proves that the louvre is affected the UV irradiance way and strength signifier this contours.

4.1.2 2 Lamps with Original Louver

In the instance of dark room state of affairss, the irradiance at degree 200cm with state of affairs of one lamp and two lamps is measured. The UV metre faces to the roof of the room to mensurate the irradiance at oculus degree since there is no different between one lamp and 2 lamps as the detector can confront the either lamp merely.

In the instance of 200cm with one lamp, the maximal value is 107I?W/cm2 and the minimal value is 0.1I?W/cm2. In the instance of 200cm with two lamps, the maximal value is 92.6I?W/cm2 and the minimal value is 1.2I?W/cm2. Furthermore, all the reading is symmetrical in this set informations. From the above contour, it can reason that utilizing 2 UV lighting in the room can supply an mean UV irradiance status and it can increase the efficiency of inactivate viral, bacterial, and fungous species.

4.1.3 No Louver

In the instance of 200cm, the maximal value is 1860I?W/cm2 and the lower limit is 0.42I?W/cm2. In the instance of 205cm, the maximal value is 3000I?W/cm2 and the lower limit is 1.4I?W/cm2.In the instance of 210cm, the maximal value is 3000I?W/cm2 and the lower limit is 2.5I?W/cm2. Besides, all the reading in this set information is symmetrical. From the above contour, it can reason that residents can non utilize UV illuming in the room under no louver status as the UV strength value is excessively big.

4.1.4 Discussion

In the instance of 205cm with all fives of louvre, the maximal value is 465I?Wcm2 and the lower limit is 2.8I?W/cm2. In the instance of 205cm with 7 fives, the maximal value is 555I?W/cm2 and the lower limit is 4.5I?W/cm2.In the instance of 205cm with 3 fives, the maximal value is 602I?W/cm2 and the lower limit is 3.3I?W/cm2.

The UV irradiance with partial fives of new louvre is measured. For the 0 degree new louvre with high end product illuming trial, the highest value of 205cm is 465AµW/cm2 and the UV irradiance value lessening far off from the lamp. At 7 fives, it shows that the UV irradiance value is larger than all fives reading and the highest value of 7 fives is 555AµW/cm2. There is same instance occurred at 3 fives and the UV irradiance value is the highest reading in 3 sets informations at 205cm and the highest value of 3 fives is 602AµW/cm2.

The UV irradiance with partial fives of new louvre with 5 grade is besides measured. In the instance of 205cm with all fives of louvre, the maximal value is 1108I?Wcm-2 and the lower limit is 6.2I?W/cm2. In the instance of 205cm with 7 fives, the maximal value is 1211I?W/cm2 and the lower limit is 5.9I?W/cm2.In the instance of 205cm with 3 fives, the maximal value is 1680I?W/cm2 and the lower limit is 7.4I?W/cm2. All the UV irradiance value lessening far off from the lamp in all fives, 7 fives, and 3 fives. Besides, all the readings in 3 fives louver is the highest irradiance value comparison with all fives and 7 fives. For the above contours, it proves that the louvre fives are affected the UV irradiance way and strength.

4.2.3 Discussion

The UV irradiance with different background stuff was besides measured. The maximal value with black paper measured by UV metre is 432AµW/cm2 and the maximal value without black paper is 257AµW/cm2. Besides the instance of 205cm, the maximal value is 17.3I?W/cm2 and the lower limit is 0.1I?W/cm2 in the instance of 200cm. Besides, the maximal value is 1.1I?W/cm2 and the lower limit is 0.1I?W/cm2 in the instance of 210cm. There have some mistake occur at the above information. In normal state of affairs, the readings without black paper should be larger than the readings with black paper since there is a coefficient of reflection with unstained steel. However, the experience reading is opposite. The grounds of an mistake occurred in this set informations due to the alteration of air temperature or speed as the airing system is operated. Hence, there is an mistake occurred in this set informations. Although the informations should be holding an mistake for strength, it can cognize that the UV irradiant is besides diverge to 200cm and 215cm signifier the above contour.

There is same instance in the 5 grade without black paper. In the instance of 205cm, the maximal value is 251I?W/cm2 and the lower limit is 1.1I?W/cm2. In the instance of 210cm, the maximal value is 58I?W/cm2 and the lower limit is 0.72I?W/cm2. There have same error occur as the 0 grade informations. In this state of affairs, the readings without black paper are smaller than the readings with black paper. Hence, the experience reading is opposite normal state of affairs. The grounds of an mistake occurred in this set informations due to the alteration the air temperature or speed as the airing system is operated. Hence, there is an mistake happening in this set informations.

4.2.3 Discussion

It is so surprised that the irradiance of measuring is more important for the black paper room than the reflected room. The ground why may be the ratio of reflected irradiance in the measuring tallness is so little in entire irradiance. Another ground may be the wall stuff will absorb the irradiance by the light beginning. The last ground as instance 4 measuring is under airing position. The ice chest air watercourse or the lower humidness of the room may be decreasing the irradiance on the upstream of the room. Therefore the irradiance of the reflected room is lower than the black room.

4.4 Fluorescent measuring

When the UV irradiance meets the fluorescent stuff, it will demo the different strength. As the consequence shows in Different degree earlier, there are different pel values showed in the LabVIEW.

There is a big different between the UV lighting on and off. The fluorescent stuff shows the UV strength straight. After that, the LabVIEW can demo the grayscale pel value. This method is more convenience than utilizing the UV metre to mensurate the UV strength value since UV metre is a point measuring but utilizing fluorescent stuff home base is a 2 dimension measuring.

This is an illustration utilizing in the 0 grade with high end product power lighting. When the fluorescent home base is located at the point 2, the mean pel value is 255. For the horizontal degree with UV illuming which was 205cm. The highest value of 205cm is 432AµW/cm2 and the UV irradiance value lessening far off from the lamp. When the fluorescent plane is located at the point 3, the mean pel value is decrease. Furthermore, when the fluorescent plane is located far off the UV lamp, the pel value besides decrease far off from the UV lamp. It can utilize this VI to make some direction for the web camera and cognize the pel from the LabVIEW. Furthermore, after acquiring the information of pel, it can make image processing from the Vision 8.5.0 Development Module. It can do a scene for a scope of strength or pel from the image.

Besides all fives with new louvre, the above diagram shows that the LabVIEW utilizing in 7 fives with new louvre. When the fluorescent plane is located at the point 2, the mean pel value is 255 as the UV strength value is 347AµW/cm2. The UV irradiance value lessening far off from the lamp. When the fluorescent plane is located at the point 3, the mean pel value is decrease to 216. Furthermore, when the fluorescent home base is located far off the UV lamp, the pel value besides decrease far off from the UV lamp. It shows the pel value is 42 and the UV strength is 48.2AµW/cm2 when the fluorescent plane is located at the point 7.

The above diagram shows that the LabVIEW utilizing in all fives with new louvre at 5 grade. When the fluorescent home base located at the point 2, the mean pel value is 255. For the horizontal degree with UV illuming which is 205cm, the UV irradiance extremum in the part closest to the leading lights. The highest value of 205cm was 550AµW/cm2 and the UV irradiance value lessening far off from the lamp. When the fluorescent plane located at the platinum 4, the mean pel value is decrease. Furthermore, when the fluorescent plane is located far off the UV lamp, the pel value besides decrease far off from the UV lamp. It shows the pel value is 61 and the UV strength is 64.8AµW/cm2 when the fluorescent plane is located at the point 7.

The above diagram is the standardization curve which is combined from the above consequence. It shows that the grayscale degree is straight relative to the figure of stand foring the brightness degrees of the fluorescent colourss. The brightness degree of the fluorescent colourss depends on the strength of UV. However, we can see the restriction from the above standardization curve as grayscale value is 255 when the maximal value is about 280AµW/cm2.

5. Decision

To reason the above consequence, it is know that the different tallness degree will supply different reading in UV illuming. In normal state of affairs, the reading should be applied for reverse square jurisprudence as UV is one sort of EM Wave. However, the UV distribution can be affected by many factors such as the tallness degree, air temperature, speed. Besides, there has a louvre in forepart of the UV lighting in the chamber. Hence, inverse square jurisprudence is non applied in this experiment but it can nearest the existent life and application of infirmary.

Hence, the above consequences can be used to happen out the best climb location of UV illuming since it shows that the strength in different conditions such as, height degree, grade of the louvre, being of the louvre, coefficient of reflection and figure of fives in the louvre between the measurings. For utilizing of ultraviolet energy to kill or demobilize viral, bacterial, and fungous species, the above factors must be concerned. The system irradiates the upper portion of a room while minimising radiation exposure to individuals in the lower portion of the room.

Future development

For the Future development, it needs to see the measurement

In this experience, there are some factors need to better,