Setup for the Realization, Maintenance, and Dissemination of the Unit of Irradiance of Low Levels in the Wavelength Range from 0.2 to 0.4 μm

The article considers issues associated with ensuring uniformity in measuring radiometric quantities within the ultraviolet range, specifically, the relevant problem of ensuring uniformity in measuring low-level irradiance (less than 10⁻⁷ W/m²) within the most required spectral range of 0.2–0.4 μm. As a result of improving GET 162-2012 State Primary Standard of the units of radiation flux, irradiance, spectral irradiance, and radiant exposure within the wavelength range of 0.0004–0.4 μm to expand the irradiance unit reproduction range toward lower levels, a modern compact measuring system was created for realizing, maintaining, and disseminating the unit of irradiance from 10⁻⁸ to 10⁻⁶ W/m² within the wavelength range of 0.2–0.4 μm. The system is included in GET 162-2022 State Primary Standard of the units of radiation flux, irradiance, spectral irradiance, and radiant exposure within the wavelength range of 0.0004–0.4 μm. The composition, operating principle, and results of studying the metrological characteristics of the system are presented. Conducted in 2020–2021, the studies confirmed the stability of the metrological characteristics defining the created system. The system provides uniformity in measuring low-level irradiance within the ultraviolet range. The obtained results can be used in various fields of technology, medicine, and biology, where highly sensitive photodetectors and low-power UV sources find a wide application.