The effectiveness of using germicidal UV is purely depended on the length of time a microorganism is exposed to light. The wavelength and the intensity of the light are also other important determinants of the entire result. The results can also be affected by the presence of some particles that can protect the microorganisms from the UV light. For you to obtain a near to correct results you have to circulate the water or the air several times through the UV light so that many microorganisms are exposed to the UV as much as possible. Sterilization is imagined in most cases as achievable. In reality it is not easy to say that you have reached sterilization results in any process and that is why you will realize many uses the word disinfection so that they do not appear to be lying about their results. You will find other firms say that they are offering 99% effectiveness. The damaged DNA of a cell can be corrected by the use of UV light. The process is referred to as light and dark repair. In this case the effectiveness will depend on the line of sight exposure to the UV light. If the bulbs have some dust coating it will lower the effectiveness. The bulbs will, therefore, have to be cleaned to make sure that the results do not interfere with so much.
At times they will also have to be replaced if you are to get results that are close to the right thing. The design of the germicidal bulbs determine how long they will live. They also rely on the various materials that are used. When there is airflow it cools the lamp making the output of the UV to go down. Therefore it is necessary to shield the lamps from airflow so that the efficiency of the UV is not affected by the cooling of the lamp. If you want to increase the performance of the UV, you can use reflection. One of the most efficient materials when it comes to reflection is aluminum. For you be able to measure the effectiveness of the UV in water disinfection, you need to compute the UV dose.
All these processes need a lot of care if you are to get the right results because a slight interference in the process will give completely different results. It is dangerous to get results that are far from the truth because that will mean the decision that are made are not correct and they will not have the intended effect. That will mean that the products made after the finds should not be trusted depending on how much are the results affected by the interference of the process. That is why regulatory bodies need to ensure everything goes in the right way.