Welcome to the LEDs Magazine UV Tech Insights newsletter for Nov. 11, 2021. The world, the English language world in particular, is full of words with subtle spelling and punctuation differences that make a huge difference in meaning. Earlier this week, our Carrie Meadows reverently mentioned a teacher that stressed the difference between “its” and “it’s.” I get that wrong sometimes, especially in text messages or emails. I know better.

But this past week, work on an article brought this situation to the forefront. And now, thinking back, I wonder if I have always correctly used the words “dose” and “dosage.” There is a difference in the two. Dose implies a simple amount while dosage is an amount over time. You might have a 50-mg dose of a medicine. But dosage might be 50 mg taken once every 24 hours.

The story that brought this issue to the forefront was a combination news report focused on UV-C technologies for disinfection. The larger section of that story covers research work done by a team from ams Osram and the University of Padua. The dose of a UV-C LED or light engine is simply the radiometric energy or wattage produced by the device or perhaps that amount related to size of the area being disinfected. The dosage becomes the value measured over time that is characterized by the far more complex mJ/cm².

In any event, the ams Osram-led research team sought to utilize an LED light engine operating at far-ranging power levels to determine equivalent dosages based on time for deactivation of a pathogen to a calculated variance. UV-C LEDs aren’t necessarily capable of producing sufficient power to immediately deactivate pathogens in a space. Instead, a product development such as an upper-air treatment system may need to account for multiples passes of air through the system to achieve the desired level of disinfection. The methodology in the research should be required reading for developers of disinfection systems.

That same article also covered a new UV-C LED from Crystal IS. The Klaran LA utilizes a homogeneous aluminum nitride (AIN) architecture. And the company says that it can produce a 100-mW dose at typical drive currents.

The whole idea of dose and dosage made me think back to some articles we have proudly produced. Early this year, we ran a contributed piece authored by experts on UV-C disinfection from Excelitas Technologies about determining the needed dose — or is it dosage — for a specific disinfection scenario. I stand by the value of that article. But we mistakenly allowed the use of dose where we really meant dosage. We’ve learned a lot this year about UV-C.

And speaking of learning, we have an upcoming opportunity for you. A week from now on Nov. 18 at noon Eastern we will have a webcast focused on accurately making UV-C measurements. We will have experts Carl Bloomfield and Jeff Davis of Intertek join with Jeff Hulett of Vektrex to present. I can assure you that it will be a valuable one-hour opportunity.

You will find many more stories of interest in the body of today’s newsletter. And always feel free to contact me to discuss content we post or to pitch a contributed article.

- Maury Wright, (858) 208-9442, [email protected]