Fiber-optic low-pressure sensors for space life support systems

To measure low pressure (measuring range 100...500 g/cm2) in narrow cavities and spaces with uneven surfaces of life support systems for aerospace objects, electrical measuring instruments are still used, which are unsafe for the health of astronauts, since an electrical breakdown of the electrical part of the measuring system of life support or electromagnetic effects from the measuring instrument on the human body. In addition to this fact, known pressure measuring instruments have large overall dimensions and a large (up to 30%) instrumental component of measurement error due to the interaction of the sensor with the measuring object. Work purpose – Development of small-sized low-pressure fiber-optic sensors operating in narrow cavities with uneven surfaces of life support systems for aerospace objects. Two designs of low-pressure fiber-optic sensors have been developed that implement a fiber-optic attenuator-reflective method for converting optical signals directly into a micro-optical-mechanical transducer system that combines the advantages of attenuator and reflective pressure transducers. It is proved that the special design of the sensing element and the outer casing of low-pressure waters can reduce the measurement error by 3...5 times. The developed high-precision low-pressure sensors of the attenuator-reflective principle of optical signal conversion can be used to measure low pressure in narrow cavities with uneven surfaces: in cosmonauts' spacesuits, in narrow pipelines of astronauts' life support systems and medical.