When browsing products for UV-disinfection, performance is usually specified according to one or both of the above. What does it mean? What performance do I need to have safe water?
Log. reduction and dose delivery or UV-dose, tells you the disinfection rate at a specified flow rate, and for a certain water quality, usually specified in UVT, or ultraviolet transmittance. Keep this in mind, if you have a higher flow rate, the disinfection will be lower, and vice versa.
UV-dose is the more common of the two, especially when looking at UV-lamps. And from this, you can check the performance for a specific microorganism at the specified flow by looking up the dose response for said microorganism. UV-dose tells which intensity of UV-light the product gives on a surface, typically measured in mJ/cm², e.g. 10 mJ/cm². Some companies instead use J/m², 10 mJ/cm² is equal to 100 J/m².
Log.reduction, needs to be specified also for a specific microorganism. If this is not specified, you can not tell whether the performance is good or bad. Log. reduction tells you how much of the bacteria is removed or deactivated compared to the levels before and after the purification. A reduction of 1 Log. is saying that 90% of incoming bacteria is removed. 2 Log. is equal to 99% etc.
When it comes to choosing your product to cover the needs you have, you need to analyse the quality of your water, so that you know what levels of pathogens you have, and how much they need to be reduced to reach a safe level. You also need to consider the desired flow rate and how much the product will be in use.
We are here to guide you.