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An automated system for controlling oxygen flow in vacuum-plasma magnetron deposition of oxides with simultaneous monitoring of gas impurities in a vacuum chamber is proposed. Features of using compact spectrometers in such a system are considered. The precision of controlling the flow of metal and oxygen particles during deposition of Ti and Al oxides is determined. The sensitivity to impurity content is estimated. The effect of sputtered metal and type of coating (metal or oxide) on the sensitivity to impurities of air, water vapor, and oil in the vacuum chamber is found.Introduction. The use of optical-spectral flow controllers for gases [1][2][3] in magnetron deposition of oxides causes technical difficulties with the recording of the intensity of oxygen spectral lines using optical sensors in light filters. A narrow-band interference light filter with a transmission half-width of less than 1.5 nm and a low transmission beyond the limits of the operating range is required to identify the strongest line OI at 777.3 nm because this line lies very close to bright argon lines, the main component of the working gas. The discharge power and pressure in the vacuum chamber must be very stable for controllers with a single-channel control algorithm to operate if the optical sensor records the intensity of spectral lines of the sputtered material [4]. Compact multi-channel radiation-spectrum recorders, for example, S100 and SL40-2 models of Solar [5, 6], and spectrometers of Ocean Optics [7] have been recently produced. These are of great interest for use in optical-spectral systems for controlling gas flow. This is due to the rather high-quality specifications of the spectrometers and their rather small size. Moreover, owing to the rapid recording of the spectrum (minimal recording time is 7 msec) and the spectral resolution, which is comparable with narrow-band interference light filters, they can also be used simultaneously to monitor the chemical purity of process plasma streams. Herein we propose a system for automated control of working gas flows in vacuum-plasma magnetron processes for depositing coatings of complicated chemical composition with simultaneous monitoring of gaseous impurities in the vacuum chamber. Features of using compact S100 and SL40-2 spectrometers in such a system as a multichannel sensor are examined using deposition of titanium and aluminum oxide films as an example. The capabilities of the system for simultaneous monitoring of oxygen, water, and oil impurities in the vacuum chamber are determined.Experimental. Experiments were conducted in a vacuum apparatus for magnetron sputtering that was equipped with a gas-flow controller [3] and devices for regulated admission to the vacuum chamber of oxygen, water vapor, and oil. We used a planar DC magnetron with discharge power of 1.0-1.5 kW and a vacuum-chamber pressure of 0.3-0.4 Pa. Oxygen flow during deposition of titanium and aluminum oxide films was controlled by a single-channel algorithm by identifying atomic spectral lines of sputtered ...