Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Spectrophotometric Method and Device for Chemosorbents Based on Alkali Metal Superoxides Absorption Capacity Diagnosing T.A. CHUPAKHINA, P.V. BALABANOV, YU.YU. GROMOV The article addresses the problem of controlling the absorption capacity of chemosorbents based on alkali metal superoxides (KO2 ) used in respiratory protective equipment. The objective of the work is to develop a non-destructive spectrophotometric method and device for diagnosing the suitability of a chemosorbent based on CO2 and O2 content. The method is based on recording the spectral radiance of samples in the visible (400–1000 nm) and near-IR (1000–1700 nm) ranges. Using the Principal Component Analysis (PCA) method, wavelengths of 465, 940, and 980 nm were identifi ed, where greatest differences between usable and unusable samples are observed. A linear discriminant analysis model was applied for classification, ensuring an accuracy of not less than 99 %. Chemosorbent samples of grade OKCh-3 with varying concentrations of CO2 and O2 were experimentally investigated. A prototype measuring device based on a photodetector, registering in three spectral channels (465, 940, 980 nm), was developed. Software in Python was created to automate the main measurement operations: calibration, graduation, and diagnostics. The photodetector sensitivity was 0,25 V/mW (465 nm channel) and 0,72 V/mW (940, 980 nm channels). Confidence intervals for calibration voltages and the conversion function of the measuring device were obtained. The results can be applied in the production and storage of respiratory protective equipment for rapid non-destructive testing of chemosorbent suitability, as well as in laboratory practice for spectrophotometric analysis of sorption materials. Keywords: absorption spectrum, visible and near-IR range, linear discriminant analysis, conversion function. DOI: 10.25791/pribor.6.2026.1685 Pp. 56-65.