The use of fiber optic technologies in measuring low pressure in space life support systems

The reproducibility of the metrological characteristics of sensors of various physical quantities used in noninvasive medical procedures or in diagnostic, rehabilitation, or life support systems currently does not exceed 30%. This fact requires new approaches to sensor design for medical and space applications. When measuring pressure in a spacesuit using low-pressure sensors in the range of 100-500 g/cm², it is required that they be safe for astronauts, since they are located close to the human body. In the developed low-pressure fiber-optic sensors, the longitudinal and transverse dimensions are reduced by 1.5...2 times in comparison with analogues. The upgraded sensor designs enable placement in cavities with limited dimensions and uneven surfaces, without resorting to special fittings or threaded connections. The design of the sensing element and the external housing of the low-pressure sensor with an attenuator-reflecting modulating element reduces the instrumental component of the error by 2...3 times. The introduction of a fixed mirror surface as an optical modulating element enabled increased manufacturability in the design of the upgraded fiber-optic pressure sensors. The proposed low-pressure sensors based on fiber-optic technologies of the attenuator-reflective principle of optical signal conversion can be used to measure low pressure in narrow spaces with uneven surfaces: in astronauts' spacesuits, in narrow pipelines of life support systems, in artificial ventilation devices, in medical diagnostic and rehabilitation systems.