극저온 밸브용 위치지시기 설계 및 제작

The position indicator for cryogenic valves used in space launch vehicle should have high reliability and accuracy. Because the valves operate in cryogenic environment, the position indicator has to measure the valve status independently of the environmental factor, such as moisture and external contamination. We have developed the position indicator using a permanent magnet and reed switches to satisfy these requirements. We analyzed the characteristics of a permanent magnet and reed switches, then selected the appropriate components for cryogenic temperature. The shape and position of components were also considered to measure the open/close information of valve accurately Finally, the position indicator was applied to the valve prototype model, and verified the feasibility of design parameters.