By M. Clark, R. Zuber and M. Ribnitzky, Gigahertz-Optik The potential of UV-C ultraviolet light in combating the spread of COVID-19 has resulted in an increase in demand for conventional technologies, such as low-pressure Hg lamps (254 nm), as well as many rapid developments in UV-C LED (260 to 280 nm) devices and products. A significant limitation is that UV radiation is both … [Read more...] about Far UV-C Germicidal Sources: Measurement Challenges and Solutions

Jim Bolton, Ph.D., president, Bolton Photosciences, Inc. In 2006, the US Environmental Protection Agency (USEPA) issued the Long Term 2 Enhanced Surface Water Treatment Rules (LT2ESWTR) (USEPA 2006) and the Ultraviolet (UV) Disinfection Guidance Manual (UVDGM) (USEPA 2006b). In 2020, the USEPA issued an additional guidance document titled “Innovative Approaches for Validation … [Read more...] about Treatment of Dependent and Independent Variables in the USEPA Guidance Manuals

Felix Becker, Ph.D. , system and application manager, ZED Ziegler Electronic Devices GmbH Thomas Rathgen, head of technical department, ZED Rolf Ziegler, Ph.D., technical director, ZED Karin Ziegler, CEO, ZED  Water treatment with UV low-pressure mercury vapor lamps is an established method to reduce pathogens in municipal drinking water.1,2 The performance of UV … [Read more...] about Reference Radiometers – Requirements and Applications

Maria Wooldridge, director of marketing, International Light Technologies, Inc. The recent coronavirus outbreak has left many hospitals and healthcare facilities scrambling to extend the use of their PPE through disinfection. To that end, many are looking at using UV-C light to disinfect materials and surfaces of viruses and microbes. Those searching for meters that measure … [Read more...] about Evaluating UV Light Meters

R.W. Stowe UV applications engineering consultant, Heraeus Noblelight America LLC The visible portion of the output (luminous flux) of lamps used for illumination is expressed in lumens, a measure of the total quantity of visible light emitted by a source. This is possible because the output is measured only in the wavelength response range of the human eye. This response … [Read more...] about Why is There No Standard Unit Similar to Lighting Products for Radiant Output of UV Lamps?

Kari Sholtes P.E. University of Colorado Boulder, Linden Research Group Karl Linden Ph.D. University of Colorado Boulder, Linden Research Group The development of a protocol to measure the peak wavelength, spectral emission and irradiance of deep ultraviolet light emitting diode (UV-C LED) devices was initiated in 2015 to standardize methods of analysis and reporting. This … [Read more...] about Summary: UV-C LED Device Spectrometer and Radiometer Protocol Round Robin Results

Stephen W. Jaworowicz Process Engineer, Light Sources, Inc. Ultraviolet (UV) lamps are an important part of water treatment plants worldwide. Daily, millions of gallons of water are made safe by using UV to inactivate microbial pathogens. In designing an effective UV water treatment unit, it is necessary to know the total UV power emanating from the lamp.  Determining the … [Read more...] about Total UV Power from an Irradiance Measurement – Correcting the Keitz Equation

Ataollah Kheyrandish Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada Madjid Mohseni Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada Fariborz Taghipour Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada A robust, … [Read more...] about Protocol to Determine Radiant Power Output and Fluence in UV LED Systems