The National Institute of Standards and Technology (NIST) has updated its UV calibration facility to ensure accurate calibration of UV detectors. The Ultraviolet Spectral Comparator Facility (UVSCF) measures and calibrates UV detection equipment sent in by industry. The germicidal properties of UV light make it useful in sanitation and disinfection, especially in healthcare settings. It is also used to combat microbial contamination in water, and for curing epoxy. This automobile-sized black box is the heart of NIST’s Ultraviolet Spectral Comparator Facility (UVSCF), which holds the instruments used to calibrate UV detectors. Courtesy of NIST/B. Hayes. Organizations that use UV light, from the military and research institutions to universities and industrial manufacturers, use calibrated UV detectors to check that UV light sources are emitting the right amount and intensity of light. NIST’s calibration system accommodates all three categories of UV light — UVA, UVB, and UVC — with each spanning distinct wavelengths. The recent update specifically emphasizes UVC light in the 200 to 300 nm range. NIST has maintained a UV calibration facility since the late 1980s, but by the mid-2010s, the facility was no longer able to meet the needs of emerging technologies like UV disinfection as it was not optimized for that particular wavelength range. The upgrade was spurred in part by the increased adoption of these technologies in the wake of the COVID-19 pandemic, NIST said.